issn 2193-4673 • Vol. 16 • Issue 3/2020 roots international magazine of endodontics 3/20 study 3D accuracy of dynamic navigation in locating calcified canals case report The importance of irrigation in challenging cases technique Remover: The ultimate solution for removing gutta-percha

editorial | Magda Wojtkiewicz Managing Editor New challenges in endodontic treatment Endodontic treatment during the COVID-19 pandemic seems to be more challenging than ever before. How do dentists ensure both their own safety and the safety of patients during therapy which cannot be performed without drilling? While the Centers for Disease Control and Prevention recommended restricted use of aerosol-generating procedures in dentistry, such as root canal preparation, and minimised risk by offering less invasive palliative care to emergency patients, many endodontists carried out successful treatment. Does it mean that they were taking unnecessary risk? Definitely not. The results of Patel et al. have shown that palliative care has been proved successful, but it is important to real- ise that this level of endodontic emergency management is only a temporary solution and that ultimately aerosol- generating procedures cannot be avoided.1 Further- more, some endodontic emergencies, such as cellulitis, can lead to major health problems, including systemic inflammatory response syndrome, osteomyelitis, para- pharyngeal abscess, cavernous sinus thrombosis and sepsis, and treatment for such endodontic emergencies should not be postponed by more than several days or even hours. Dental professionals are very aware of the importance of infection control and implement cleaning and dis- infection procedures in dental offices daily. Also the use of protective equipment, such as masks, shields and disposable aprons, is a standard procedure in most clinics; therefore, there is nothing new with respect to strict hygiene protocols in dentistry. In conclusion, avoiding endodontic treatment during the COVID-19 pandemic is not a solution, but all procedures should be conducted according to the protocols and recommendations of the relevant advising organisations. It will probably take a great deal of time before we learn how to live with SARS-CoV-2, but what we know so far has made it clear that respecting the necessary pro- cedures can allow us all to work safely. Magda Wojtkiewicz Managing Editor Reference 1 Patel B, Eskander MA, Ruparel NB. To drill or not to drill: management of endo- dontic emergencies and in-process patients during the COVID-19 pandemic. J Endod. 2020 Aug 22;46(11):1559–69. doi: 10.1016/j.joen.2020.08.008. roots 3 2020 03

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feature | “Hopefully, the fi ndings of our study will help dentists manage patients without aerosol-generating procedures during periods of lockdown.” m o c . k c o t s r e t t u h S / v o n a g a a G l among dentists about all in-process pending procedures started before the statewide shutdowns. To drill or not to drill? Researchers from the Department of Endodontics at the University of Texas (UT) School of Dentistry conducted a two-part study in order to investigate how endodontists could work around these extreme conditions while man- aging their patients’ pain. The results of the first part of the study showed that 81 % of the 21 patients who presented with endodontic emergencies in 25 teeth during the state- wide shutdown required no further treatment or interven- tion after palliative care at a follow-up rate of 96 %. In the second part, 31 teeth had received partial or full root canal debridement before the statewide shutdown. The mean time for completion of treatment was 13 weeks. At a recall rate of 100 %, 77 % of the teeth did not expe- rience any adverse events resulting from delays in treat- ment completion. The most common adverse event was a fractured provisional restoration (13.0 %), followed by a painful and/or infectious flare-up (6.4 %). These events were managed appropriately and therefore deemed successful. Only one tooth was fractured and nonre- storable (3 %), leading to the failed outcome of tooth extraction. The remaining four outcome failures (13 %) were due to patient unwillingness to undergo school- mandated SARS-CoV-2 testing or patient unwillingness to continue treatment because of perceived risk of SARS-CoV-2 infection. In an interview with Dental Tribune International, study co-author Dr. Biraj Patel explained the reasoning behind this study: “The school decided to defer aerosol-generating procedures in accordance with the state guidelines. We managed cases very differently to what we would have routinely done and were interested to see how successful we were. Furthermore, the literature has limited data on the effect of delaying treatment in endodontics and the out- comes of the palliative management of endodontic disease. Our report on the management of endodontic emergencies has important clinical implications for the dental commu- nity worldwide and aims to provide an insight into the effect of conservative management of endodontic emergencies without the use of aerosol-generating procedures.” As results have shown, palliative care proved success- ful for the UT researchers, but it is important to note that this level of endodontic emergency management is only a temporary solution and aerosol-generating procedures cannot be avoided forever. “The state witnessed a lock- down from 23 March to 20 May 2020, and palliative care was successful in managing patient symptoms during this time. However, if this lockdown had been longer, we may have had to reevaluate patients if they became symptomatic and potentially intervene with aerosol-generating procedures,” said Patel. What is the long-term solution? “At present, our school reduces the risk of transmission by testing all patients for SARS-CoV-2 using reverse transcription-polymerase chain reaction (RT-PCR) prior to aerosol-generating procedures,” the endodontist added. “We make sure to follow the state and CDC guidelines, especially with regard to social distancing measures and personal protective equipment. We hope that a better understanding of the transmission of SARS-CoV-2, along with developments in rapid testing, will eventually reduce the risk to healthcare professionals. This will hopefully result in a reduced need for clinics to stay closed. The expectation is that we will see further lockdowns if cases of COVID-19 become uncontrolled. Hopefully, the findings of our study will help dentists manage patients without aerosol- generating procedures during periods of lockdown.” Editorial note: The study, titled “To drill or not to drill: Management of endodontic emergencies and in-process patients during the COVID-19 pandemic,” was published on 22 August 2020 in the Journal of Endodontics. roots 3 2020 09

study | a b o p c g k d h l e i m q u v w r s t f j n x y z Figs. 1a–z: The Navident workflow. Scan: A pre-op CBCT scan of the custom TrueJaw model is acquired (a & b). Plan: The CBCT scan is imported into Navident, and the 3D virtual access trajectories are planned. The CBCT coronal and sagittal views of tooth #41 (c–f), tooth #33 (g–j) and the second mesiobuccal canal of tooth #16 (k–n), serving as a guide for planning non-surgical virtual 3D access cavities/paths of 1 mm in diameter. Trace: Six landmarks (starting points for tracing) selected on the 3D rendered image on each of the maxillary (o) and mandibular models (p) on the screen. Clinical tracing on the jaw model with a tracer tool in order to register the CBCT scan to the model for the following navigation step (q). Place (navigated access): The bur orientation and the drilling guided by target views on the computer screen for tooth #41 (r–t), tooth #33 (u–w) and the second mesiobuccal canal of tooth #16 (x–z). The depth of the burs was monitored and indicated by the green bar of the depth gauge; the colour changed from green to yellow when within 1 mm of the desired depth and from yellow to red when the correct depth was reached. roots 3 2020 11

study | canal orifice depth and the discrepancies between the actual and planned access cavities. The discrepancies were measured in the 2D entry, 2D horizontal and verti- cal deviation from the canal orifice, 3D deviation from the canal orifice and 3D angular deviation. In addition to the discrepancies, a model for the total time was fitted with the same predictors. The significance level was set at p = 0.05. Backward elimination was used to reach a par- simonious model. Only terms with p < 0.05 were consid- ered for the final model. Post hoc pairwise comparisons were adjusted using Tukey’s adjustment. The null hypoth- esis was that the discrepancies and drilling time were independent of the tooth type, jaw and canal orifice depth. Results A total of 138 canals were drilled, 78 in maxillary and 60 in mandibular teeth. Of these, 36 were in anterior teeth, 72 were in molars and 30 were in premolars. The average drilling time was 57.8 seconds, and the average canal ori- fice depth was 12.4 mm. The overall mean 3D canal orifice deviation was 1.3 mm, the mean 3D angular deviation was 1.7°, and the mean 2D entry deviation, horizontal deviation from the canal orifice and vertical deviation from the ca- nal orifice were 1.1 mm, 0.9 mm and 1.0 mm, respectively. Descriptive summary statistics and the results of the ANCOVA analysis are given in Table 1 and Table 2, respectively. Drilling time was dependent on the canal orifice depth (p = 0.0007), tooth type and jaw, and the differences in tooth type were dependent on the jaw (p < 0.0001). For a 1 mm increase in the canal orifice depth, the drilling time increased by 7.6 seconds (95 % confidence interval [CI]: 3.26–11.91). The 2D entry deviations were higher in the maxilla (1.23 vs 0.85; 95 % CI on difference: 1.05–0.65). The 2D horizontal deviation from the canal orifice was significantly higher for the maxillary teeth compared with the mandibular teeth (p = 0.0206). The average deviation for the maxillary teeth was 0.97 mm compared with 0.70 mm for the mandibular teeth, producing an average difference of 0.27 mm (95 % CI on difference: 0.04–0.50). The 2D vertical deviation from the canal orifice was depen- dent on the tooth type (p = 0.0344). Post hoc pairwise com- parisons found that molars had significantly higher average deviation than premolars did (adjusted p = 0.0270). The 3D deviation from the canal orifice was marginally significantly different between the two jaws (p = 0.0523). The average deviation was higher in the mandible at 1.4 mm compared with 1.2 mm for the maxilla (95 % CI on dif ference: 0.00–0.44). Overall, 3D angular deviation was dependent on the tooth type (p = 0.0288). The average deviation for molars was 1.9°, significantly higher than the 1.4° average for premolars (adjusted p = 0.0403; 95 % CI on difference: 0.02–1.00). The average for anterior teeth (1.5°) was not significantly different from that for molars (adjusted p = 0.1633) or premolars (adjusted p = 0.7943). All 2D and 3D discrepancies were independent of the canal orifice depths (p > 0.05). Discussion This is the first study to demonstrate and evaluate the potential use of high-speed drills and precision micro- endodontic high-speed burs with dynamic navigation to effectively prepare conservative access cavities in anterior Table 1: Summary of time, depth and discrepancy measures by jaw and tooth type (mean, SD) Measures Overall Jaw.. Tooth Type Maxilla Mandible Anterior Molar Premolar Total time (s) 57.8, 61.91 45.6, 41.20 67.2, 72.89 142.1, 63.46 32.2, 21.14 18.2, 8.11 Canal orifice depth (mm) 12.4, 4.04 13.6, 3.71 11.5, 4.08 18.8, 1.83 10.2, 0.89 10.2, 1.84 2D entry deviation (mm) 1.1, 0.80 0.9, 0.65 1.2, 0.87 1.0, 0.80 1.0, 0.80 1.2, 0.82 2D horizontal deviation from canal orifice (mm) 2D vertical deviation from canal orifice (mm) 0.9, 0.69 1.0, 0.78 0.7, 0.51 0.8, 0.57 0.9, 0.77 0.8, 0.60 1.0, 0.64 0.9, 0.68 1.0, 0.60 0.9, 0.63 1.1, 0.66 0.7, 0.52 3D deviation from canal orifice (mm) 1.3, 0.65 1.2, 0.57 1.4, 0.70 1.3, 0.59 1.4, 0.71 1.1, 0.56 3D angular deviation (°) 1.7, 0.98 1.7, 0.90 1.7, 1.04 1.5, 0.78 1.9, 1.14 1.4, 0.62 roots 3 2020 13

study | of 3.5°.28, 29 Studies on in vitro models for implant placement indicate that dynamic navigation systems with slow-speed drills have a mean entry deviation approximating 1.2 mm and a mean angular deviation approximating 4°.30 The 2D horizontal deviation from the canal orifice has greater significance for endodontic applications because increased drilling depths could lead to loss of tactile guidance. In such an event, horizontal deviations can cumulatively increase the risk of perforation or iatrogenic error.31 The results of our study found a mean 2D horizontal deviation of 0.9 mm from the canal orifice with high-speed drills. This discrepancy could be considered relatively safe for deep endodontic access cavity preparation. The indirect method of locating the access cavity through the placement of a drill in the cavity for the postoperative CBCT may have introduced possible errors from image ac- quisition and bur positioning. These errors can be cumula- tive and interactive, impacting on all the parameters. Future studies using sophisticated segmentation techniques, 3D image processing (micro-CT) and analysis to quantify the difference between the planned and the prepared access cavities are warranted for detecting higher 3D accuracy.32 A certain level of technical skill, hand–eye coordination and manual dexterity is necessary in order to drill from the entry point to the target while looking at the computer screen. Clinical success can be dependent on the hand skills of the operator owing to the inaccuracies caused by hand tremor and perception of 0.25 mm and 0.5° involved with bur and handpiece tracking.33 Simulation of dynamic navi- gation shortened the learning curve for clinicians perform- ing colonoscopy and improved training of novice endosco- pists.34 Novice operators have demonstrated a significant improvement in implant placement skills with dynamic navigation with as few as three attempts to up to 20 at- tempts.21, 35 The operator in this study practised on over 20 samples and developed a stable and consistent work- flow to minimise the influence of the learning curve and operator-induced error. The updated second-generation trace registration system can perform registration with pre-existing small field of view CBCT scans, thereby reducing the amount of radiation exposure. This is distinctively different from the first- generation navigation system, which requires additional CBCT scans with thermoplastic stents (NaviStent) and radiographic fiducial markers.26 The cost and time con- siderations associated with thermoplastic stent fabrica- tion and errors associated with it can be eliminated, mak- ing it clinically feasible for endodontic procedures. Future studies on the application of this technology in the areas of endodontic retreatment and microsurgery may unlock new synergies and minimise iatrogenic error. The recent upgrades in this technology have enhanced chairside clin- ical feasibility, which may lead to efficient patient care and predictable outcomes. Conclusion Optically driven, computer-aided 3D dynamic navigation technology with high-speed drills can achieve minimally invasive access cavities in locating highly difficult simulated calcified canals with a mean 2D horizontal deviation of 0.9 mm from the canal orifice, mean 3D deviation of 1.3 mm from the canal orifice and mean 3D angular deviation of 1.7°. Acknowledgements This project was supported by a grant from the Virginia Commonwealth University School of Dentistry. The authors (SDJ and CKC) report no conflicts of interest related to this study. One co-author (IB) is an employee of ClaroNav. The authors acknowledge Dr George Deeb (associate professor in the Department of Oral and Maxillofacial Sur- gery at the Virginia Commonwealth University School of Dentistry) for allowing access to the Navident system. Editorial note: A list of references is available from the pub- lisher. This article originally appeared in the Journal of End- odontics (Volume 46, Number 6, June 2020), and an edited version is provided here with permission from the author. about Dr Sameer D. Jain, BDS, MS, MSD, is an assistant professor in the Department of Endodontics of the Virginia Commonwealth University School of Dentistry in Richmond in the US. 520 North 12th Street Box 980566 Richmond VA 23298-0566 USA sdjain@vcu.edu Dr Caroline K. Carrico, BS, PhD, is an assistant professor in the Department of Dental Public Health and Policy of the Virginia Commonwealth University School of Dentistry. 1101 East Leigh Street Box 980566 Richmond VA 23298-0566 USA ckcarrico@vcu.edu Dr Ido Bermanis, DMD, MSc, is director of clinical affairs at ClaroNav. 1140 Sheppard Avenue West, Unit 10 Toronto ON M3K 2A2 Canada ido@claronav.com roots 3 2020 15

case report | 2 a c b d e Fig. 2: Surgical procedure. A full-thickness mucoperiosteal flap was raised, ex- posing the overlying the intact cortical bone of tooth #15 (A). The periphery outline of the cortical window (bone lid) is shown. The efficacy and accuracy of Dynamic Navigation enables minimally invasive resection owing to the real-time feedback capability of the software (B). The calibrated avatar saw tip is visible in the frames of the Navident interface (C); camera view of the patient and optical tags (a); panoramic view (b); rendered view (c); coronal view showing the saw position (d); axial view showing the saw position (e). The coronal and axial views show the move- ment of the saw, providing real-time feedback of its position during the surgery. the maxillary sinus while performing EMS on a maxillary premolar in an anatomically challenging space. Case report A 50-year-old male patient presented with moderate pain associated with a previously treated maxillary right second premolar (tooth #15). The medical history was non-con- tributory. The tooth had been endodontically treated and restored with a cast post and core and a complete crown. The patient’s CBCT scan revealed two separate roots, an intact buccal plate and an apical lesion associated with the palatal root (Fig. 1). The tooth was moderately sensi- tive to vertical percussion, and periodontal probing depths and mobility were within normal limits. The diagnosis was symptomatic periapical periodontitis associated with a pre- viously treated tooth. After consultation, the patient chose to have EMS treatment done with dynamic navigation. The proximity of the palatal root apex to the sinus floor raised the issue of an existing sinus perforation or the risk of iatrogenic creation. Dynamic navigation enabled real-time feedback of the position of the instrument tip on the z-axis as it accessed the palatal root apex. Lidocaine (2 %) with 1:80,000 adrenaline (New Stetic) was used to achieve profound local anaesthesia, and a full-thickness mucoperiosteal flap with a vertical re- leasing incision was elevated (Fig. 2A). Three landmarks (up to six can be used) were marked on teeth displayed in the patient’s scan in a non-collinear array. A head tracker (optical marker) was secured to es- tablish jaw position, a tracer tag attached to a tracer tool and a stentless trace registration of the maxilla done by creating a cloud of points around the landmarked teeth, thus accurately mapping the avatar maxilla on the CBCT. An accuracy check was performed to verify the trace regis- tration, a drill tag (optical marker) was secured to the Piezo- tome Cube handpiece (ACTEON) with an adapter, the LC2 saw (ACTEON) secured to the handpiece and the saw tip calibrated. The dynamic navigation software algorithms enable the micron tracker (stereoscopic camera) to identify the avatar saw tip as it cuts the periphery and depth of the cortical window (Figs. 2B & C). The position of the saw at the periphery of the palatal root resection can be precisely tracked, thus preventing a sinus communication (Figs. 3A & B). The retro-preparations were done using an E30RD ultrasonic tip (NSK). Fig. 3: Preparation of the root end. The progress of the saw is monitored as it moves through the bone and resects the apex of the root (A). The bone lid has been removed, the buccal and palatal roots resected and the apical extent of the root canal space retro-prepared (B). The retro-preparations were retro-sealed (C). 3 roots 3 2020 17

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case report | 8 10 9 11 After positioning of the dental dam (Fig. 2), the existing composite filling in the centre of the crown was removed using a diamond-coated bur driven by a high-speed handpiece. In this way, the access cavity was created and refined in order to see the pulp chamber (Fig. 3). The existing root canal filling was removed using rotary instruments specifically designed for retreatment, and then ultrasonic tips were used to remove the remnants on the pulp chamber floor. The chamber was filled with 5 % sodium hypochlorite (Fig. 4), and the second mesio- buccal canal, which had not been shaped, cleaned or filled during the initial treatment, was located and shaped according to the standard protocol. or activation of irrigants1 by means of ultrasonic/sonic devices15 or negative pressure devices.16 The closer the needle is to the working length, the greater the irrigation is. For this reason, using products that fol- low the anatomy of the prepared root canal can help in this clinical step. However, the flux must not be violent, in order to decrease the risk of extruding debris into the periapical tissue.17 Several articles have described the use of a novel poly- propylene needle (IrriFlex, Produits Dentaires) charac- terised by a back-to-back side vent design that helps the clinician irrigate the root canal space efficiently and safely. This product, with its 30-gauge tip, has the ad- vantages of reaching the working length effortlessly and of bringing a high volume of irrigant close to the apex. The product has been shown to be effective in curved canals, but what about challenging cases? The following case reports demonstrate the use of IrriFlex in two dif- ferent scenarios: a retreatment and a primary treatment of a calcified canal. Case 1 A 62-year-old patient was referred to our clinic for end- odontic retreatment. The patient reported swelling of the maxillary left gingiva. The radiographic examination revealed the results of a previous endodontic therapy and the presence of periapical radiolucencies (Fig. 1). Since the results of the previous therapy could be improved, we decided to retreat the tooth, passing through the existing crown. 12 roots 3 2020 21

case report | 18 19 enlarged using ultrasonic tips. Then nickel–titanium rotary instruments were used to complete the shaping of this narrow root canal space (Fig. 15). Multiple irrigation sequences were repeated using IrriFlex and ultrasonic activation of the sodium hypochlorite, both in order to have the endodontic instruments work in the presence of an irrigating solution and to decrease the bacterial load.20 The great advantage of using a polypropylene irrigation cannula was that, once the last shaping instrument had reached the working length, the cannula reached the working length smoothly too (Figs. 16 & 17), allowing the dentist to bring the irrigant as close as possible to the apical constriction.1 In both cases, the use of a flexible irrigation cannula that follows the path created by the endodontic instruments pre- cisely made the treatment easier and reduced operating times, because it was possible to deliver a large volume of irri- gating solution where it was needed the most. The presence of length marks on the cannula helped the clinician establish the needle penetration inside the root canal; the yellow stop was put on the cannula to emphasise the correspondence between working length and IrriFlex depth of penetration in- side the prepared canal. Obturation with warm gutta-percha was performed in order to seal the root canal space in 3D, and the choice to restore both teeth in the same appointment as that of the root canal therapy was meant to prevent cor- onal leakage often associated with provisional restorations. When the root canal walls looked sufficiently clean and shiny, obturation with warm gutta-percha was performed. As a last step of the endodontic treatment, a build-up was done with composite (Fig. 18) and a periapical radiograph was taken (Fig. 19). about Conclusion The same experienced practitioner performed the two root canal therapies reported in this article. The cases were extremely different, an initial treatment of a single-rooted tooth and a retreatment of a multi-rooted tooth, but both of them were challenging. The instruments and the sequences used for shaping the root canal system differed between the cases, since the root canal taper was differ- ent and the apical size of the lateral incisor was discernibly smaller than that of the molar. The thing that did not change in the approach to these cases was the attention paid to the irrigation step. In the retreatment, the eradication of bacteria was the key to success in a tooth that had already received an endodontic treatment that had failed, whereas in the lateral incisor, the presence of a narrow canal made it more difficult to clean the complexity of the root canal system.21 Dr Marco Martignoni graduated from the Gabriele d’Annunzio University of Chieti–Pescara in Italy in 1988. From 1989 through 1991, he completed continuing education courses at the Boston University Henry M. Goldman School of Dental Medicine in the US, presented by Dr Herbert Schilder. In 1992, he completed a continuing education programme presented by Dr Cliff Ruddle in Santa Barbara in the US. He runs a private clinic in Rome in Italy, and the practice is dedicated mainly to endodontics, pre-prosthetic core build-ups and prosthodontics. He has conducted and published research on post-endodontic core build-ups. He is a well-known speaker and has given numerous lectures and practical workshops in Italy and worldwide on endodontics, on core build-ups and on the use of the operating microscope in dentistry. He is founder of the Accademia Italiana di Odontoiatria Microscopica (Italian academy of microscopic dentistry) and an honorary member of the Société Française d’Endodontie (French society of endodontics). roots 3 2020 23

research | Chemomechanical systems Positive pressure systems Negative pressure systems XP-endo Finisher Self-Adjusting File Hand dynamic Sonic Multi-sonic Ultrasonic Laser-activated irrigation (PIPS* and SWEEPS**) EndoVac * PIPS = photon-induced photoacoustic streaming. ** SWEEPS = shock wave enhanced emission photoacoustic streaming. Table 2: Irrigant agitation techniques. Chlorhexidine Chlorhexidine (2 %) has good antibacterial properties, but it is not able to dissolve pulp tissue. This suggests its use only in an additional final decontamination step because of its unique substantivity property, which could allow persistent residual antimicrobial action. It is important to prevent interaction between NaOCl and chlorhexidine, by rinsing the canals with distilled water in between solutions to avoid the formation of precipitates that may discolour the tooth and that may contain potentially mutagenic compounds.9,10 Its inability to dissolve organic tissue also explains the absence of toxicity to periapical tissue.11,12 Other solutions Other chemical solutions have been investigated and used in endodontics. Among these, hydrogen peroxide, iodine, citric acid, ozone (gas) and ozonated water are available, but none of them have demonstrated supe- rior properties and results to the previously cited NaOCl and EDTA solutions. EDTA plus Cetavlon and a mixture of doxycycline, citric acid and a detergent are new solu- tions that combine different components, surface-active agents and antibiotics which can be very effective and have broader action. The experimental use of nanoparti- cles is also very promising. Irrigant activation techniques The initial irrigation phase and the irrigation during shap- ing are performed using a syringe with an end- or side- vented needle that can only negotiate the canal up to the middle third. Therefore, it must be considered that the ef- ficacy of hand irrigation is quite limited; thus, supplemen- tary, active and dynamic irrigation (Table 2) is proposed at the end of the treatment to ensure the cleaning of the dentinal walls and the deep decontamination of the endo - dontic system.13 Among the various activation methods, we can find systems that heat the irrigating solutions or that activate the solutions by agitation, with positive or negative apical pressure. Heating Scanning electron microscope studies on intra-canal heating of NaOCl at 180 °C have proved this method to be more effective for cleaning the canal walls than extra- canal heating at 50 °C, which left a higher quantity of debris and the smear layer widely distributed.14 Other studies have reported that NaOCl at a concentration of 1 % heated to 60 °C was significantly more effective than 5.25 % at 20 °C. The advantage of using lower concen- trations of NaOCl, heated to higher temperatures, could be related to a twofold effect: the same effectiveness and less systemic toxicity than that of non-heated, high- concentration NaOCl.15 Agitation techniques However, the effect of agitation on tissue dissolution was proved greater than that of temperature and with contin- uous agitation resulted in the fastest tissue dissolution.16 Comparing the efficacy of various agitation systems, De Gregorio et al. found a limited penetration of the irrig- ant into lateral canals using an apical negative pressure irrigation system, whereas passive ultrasonic irrigation demonstrated significantly more penetration of irrigant into lateral canals.17 Nevertheless, it could be reasonable to combine the two techniques, using heated NaOCl and agitating it with the preferred method. Laser-activated irrigation using SWEEPS The physical concepts behind laser-activated irrigation and SWEEPS technology have already been explained in a previous issue (4/2019) of this magazine.18 One of the great advantages of SWEEPS over all of the other acti- vation techniques is its profound effectiveness. Unlike all the other techniques, SWEEPS action is not limited to the vicinity of the tip, as is the case with ultrasonic irrigation, but it is also effective at distant regions of the root canal system.19,20 For this reason, SWEEPS only requires posi- tioning of the tip in the access cavity to stream the irrigant into all of the endodontic space at the same time. This is different to other techniques, which require needle or tip/ roots 3 2020 25

research | preliminary step is mandatory to minimise leakage and reinfection. Furthermore, good marginal sealing prevents any irrigant extrusion during laser-activated irrigation. Access cavity preparation At this point, the access cavity is opened using a small carbide, or cylindrical or round diamond bur under mag- nification (4.5–6.0 x). Traditional access cavity prepara- tion, following the laws of centrality and concentricity, is advisable (Fig. 5).30 Several studies have demonstrated the lack of usefulness of ultra-conservative “ninja” ac- cess cavity preparation in terms of fracture strength and preservation of the original canal anatomy during shaping compared with traditional access cavity preparation, par- ticularly at the apical level. Furthermore, standardised ac- cess cavity preparation is advisable when the X-SWEEPS modality is chosen for laser-activated irrigation. Future publications will explain this topic in depth in order to es- tablish the correct laser settings to be used with stan- dardised access cavity preparation volumes. Whatever the pathology is, the concept is to minimise the root canal shaping, optimising the cleansing and decontam- ination of the endodontic space by exploiting the che- momechanical flushing of SWEEPS. The main difference between asymptomatic and symptomatic pulpitis and apical periodontitis therapy is in the longer or shorter ini- tial NaOCl SWEEPS-activated irrigation phase. Retreat- ment also involves a few differences in the energy ap- plied during the initial phase when filling material has to be removed. Asymptomatic and symptomatic irreversible pulpitis In the case of irreversible pulpitis, the pulp is irreversibly inflamed, with or without acute symptoms. The patient’s age and preoperative radiograph give information on a possible immature apex; this condition contra-indicates a full-power SWEEPS irrigation and suggests a more care- ful intervention and lowering of the energy used (more to follow). Once the pulp chamber has been opened, ex- cessive bleeding may be present, indicating the pres- ence of inflamed pulp tissue inside the chamber and root canals. In this case, one-visit therapy is advisable. The treatment starts with NaOCl irrigation by syringe (3–5 ml) and simultaneous activation by Er:YAG laser (2,940 nm; LightWalker AT, Fotona), using the dual-pulse (25 µs du- ration) Auto-SWEEPS modality for 30–40 seconds. The resting time after irrigation can be extended to 1–2 min- utes to allow more NaOCl pulp dissolution. A flat- or radial-ended SWEEPS tip (400 μ) is used. The pulp tissue may show different grades (levels) of inflammation, up to initial necrotic degeneration. It is important to consider at this stage whether the pulp tissue itself is preventing any extrusion of the irrigant so that full-power Auto-SWEEPS activation (20 mJ at 15 Hz and 0.6 W) can be performed up to almost complete pulp dissolution, which is indi- cated by a progressive decrease in bleeding. According to the tooth type and condition, this initial phase can be 6 Fig. 6: After the cavity access has been prepared, laser-activated irrigation of NaOCl using SWEEPS is performed in the access cavity. Then lubricant gel containing urea peroxide is placed on the file (or in the cavity) to lubricate and avoid tissue plugging when sliding the file to the apical constriction. (Courtesy of Dr Giovanni Olivi) repeated for two to three cycles for single-rooted teeth and up to three or four cycles for premolars and molars. The initial irrigation phase also decreases the bacterial load. The access cavity can now be observed under magnification (6–10 x) in order to locate all canal orifices. If the orifices are not all visible, the use of ultrasonic tips can easily discover orifices hidden under calcification in the pulp chamber. These are usually located at the angles, at the floor–wall junction and at the terminus of the root de- velopmental fusion lines. Then pre-flaring of the orifices and enlarging of the coronal thirds of the canals allow easy and direct access to the canals. Subsequently, a direct glide path to the apical third is established by hand or dedicated rotary instruments, up to 3–4 mm from the apex. This manual or rotary instrument step produces debris and dentine chips that must be removed by Auto- SWEEPS NaOCl irrigation, again for 30–40 seconds, followed by 30 seconds of resting time. At this point, use of a small stainless-steel hand file (ISO 06 to 10) is rec- ommended with a cream containing urea peroxide or EDTA to lubricate and avoid tissue plugging when slid- ing the file to the anatomical opening to scout the canal and determine the anatomical length (Fig. 6). It must be emphasised that by now most of the pulp tissue will have already been dissolved by NaOCl and the possibility of dislodging pulp remnants or debris inside unreachable anatomical areas is very difficult if the previous phases have been correctly followed. Also, the bacterial load is highly decreased so that apical transportation of bacte- ria is minimal or absent. Use of an electronic apex locator and radiographic confirmation provide verification of the anatomical length of the tooth. Different approaches to the apical constriction can be used: working to the anatomical length or 1 mm shorter, roots 3 2020 27

research | ing is more than ISO 40–50, a simple operation that per- mits control of any unwanted irrigant extrusion is the use of a particularly smooth needle file of different calibres (from ISO 40 to ISO 100). The apical end closes the api- cal opening of the canal while laterally all the irrigant flows throughout the canal. Calcified canals Sometimes canal restrictions and calcifications, due to tertiary dentine formation, may be found, hindering the negotiation of the canal (Figs. 9 & 10). In case of a multi- rooted tooth, another canal may be accessible and the usual protocol can be applied up to completion of root canal filling (Figs. 11–13). In a separate session, the cal- cified canal is irrigated by EDTA solution, activated and forced by full-power Auto- SWEEPS, at 40 mJ and 15 Hz (Figs. 14 & 15). The single-pulse USP mode (25 µs) can also be more effective for pressure generation. Note that, if the canal is obstructed by calcification while the other canals have already been prepared with files, this proce- dure at higher energy is very safe. EDTA in this case is used to chelate and soften the dentine, but sometimes the use of a thin, rigid ultrasonic tip is necessary to re- move the calcification in the coronal third. Stainless-steel hand files with EDTA gel can be used to help bypass the blockage in the middle and apical thirds. Final irrigation protocol At the end of the preparation and before the final irriga- tion protocol, the root canal system has already been cleansed and disinfected by the SWEEPS protocol used from the beginning of the therapy. Further research is re- quired to confirm the reported efficacy and effectiveness of SWEEPS’s cleansing ability and pressure generation regarding decontamination. Several researchers have re- ported the superior decontamination results of the SSP modality using PIPS.34–36 Therefore, this evidence-based protocol is used for the final NaOCl disinfection (Fig. 16). Continue using the tip size and shape (flat- or radial- ended) chosen: – Two cycles of 30-second EDTA (15–17 %) irrigation by syringe is performed, delivered in the access cavity and activated by Auto-SWEEPS at 20 mJ and 15 Hz. In case of an open apex, the energy can be reduced to 15 or 10 mJ. Each cycle is followed by 30 seconds of resting time, to allow the solution to react on the dentinal walls. At this point, gutta-percha points can be tested after calibrating length and apical size. Apical friction and retention should be checked and adjustments made if necessary. This simple operation contributes, with its hand dynamic action, to irrigation efficacy. – One cycle of 30-second irrigation with distilled water (or water directly from the 0/1 laser spray) is performed to rinse the canals before the final decontamination. 9 10 11 12 13 14 15 Fig. 9: The symptomatic maxillary second premolar showed a periapical lesion on radiographic examination. The preparation of the buccal and palatal canals was performed with a 25/.08v ProTaper Gold (F2) to 4 mm short of the radiographic apex. A size 10 hand instrument was used up to 2 mm short of the apex. Fig. 10: The calcified canals hindered the nego- tiation of the apical constriction. Full-power Auto-SWEEPS (40 mJ, 15 Hz) activation of 15 % EDTA solution was able to force through the blockage to cleanse and disinfect the last 2 mm of the confluent curved canals. Obturation was performed with Thermafil and AH Plus sealer. Fig. 11: A symptomatic maxillary first molar with large mesioocclusal decay and a large periapical lesion. Fig. 12: Root canal preparation was performed with a 25/.06 ProTaper Next X2 (Dentsply Sirona) in the buccal canals and 40/.06 X4 in the palatal canal, which demonstrated pre- existing api- cal resorption. Obturation was performed with EndoSequence BC Sealer (Brasseler) and gutta-percha. The first and second mesiobuccal canals merged into one unique larger canal in the apical third. Fig. 13: The three-month post-op radiographic examination showed that healing was progressing rapidly. Fig. 14: Radiograph showing deep distal caries with a large periapical lesion on symptomatic tooth #47. The mandibular molar presented with a typical C-shaped canal, and it was prepared with an ISO 25/.06 TF Adaptive file. Fig. 15: Auto-SWEEPS (20 mJ, 15 Hz) ac- tivation of 4 % NaOCl and 15 % EDTA solution was able to dissolve the tissue and debris from the complex radicular anatomy, allowing a sealer (EndoREZ, Ultradent) to fill the full endodontic space (five-month post-op radiograph). roots 3 2020 29

technique | 3a 3b 3c 3d 3e 3f 3g 3h Figs. 3a–h: Retreatment of a tooth #46 pre-op radiograph (a); the Remover is positioned at the entrance to the mesiolingual canal (b) and is progressively advancing into the gutta-percha (c); pathway created by the Remover after its first central advance into the gutta-percha (d); mesial canals after shaping and mechanical irrigation (2Shape TS2 and F35 finishing files, COLTENE MicroMega) (e); pre-op radiograph to check the master cones (f); post-op radiograph centred (g); post-op radiograph offset (h). (Images 3–4: © Jean-Philippe Mallet) mechanical performance of nickel–titanium (NiTi) files led to new file systems that are more flexible and more resis- tant to cyclic fatigue. The Remover (COLTENE) has bene- fited from all these technological advances and concepts for removal of obturation material. Removal of different sealers A retreatment file is supposed to go through the deficient obturation material and remove it from the canal. This material generally includes a core material (gutta- percha) sealed to the canal walls with a fine film of end- odontic sealer. Different types of sealers have been used over the years. Historically, zinc oxide eugenol sealers were the first, but many others have been proposed to improve different properties of the sealer. These include resin-based sealers to improve the hermetic seal and adhesion to the canal walls; silicone-based sealers, which are well tolerated by tissue and have low water resorption; epoxy resin-based sealers for the possibility of adhesion to dentine and lower rates of water solubil- ity; sealers based on mineral trioxide aggregate which have a predilection towards mineralisation; calcium silicate sealers, commonly referred to as “bioceramics” owing their excellent biological properties; and calcium phosphate and calcium-enriched mixture sealers with roots 3 2020 33

technique | 6a 6b Figs. 6a & b: Pre-op radiograph of a maxillary first molar presenting with periapical periodontitis with a forgotten canal in the mesiovestibular root (a). Post-op radiograph after filling removal with the Remover, cleaning and shaping with the 2Shape and apical finishing with the F40 (0.40 tip and 4 % taper) in palatal and distobuccal canals (b). Flexible retreatment about The Remover is available in two lengths: 19 and 23 mm. A large number of cases can be addressed with 19 mm files. If the 19 mm Remover does not reach the full extent of the filling material, the 23 mm file can be used to make up for the missing millimetres. This new instrument, specifically designed for endodontic retreatments, embodies the current concepts in endodontics and uses the most recent advances in technology (asym- metry, electropolishing and heat treatment). The diameter of the wire of the Remover is only 1 mm, which makes it smaller than that of the majority of reshaping or retreatment instru- ments. Moreover, it allows for minimally invasive removal of filling material while ensuring increased blade flexibility. It is a single-use instrument; however, removing the filling material from two teeth in the same patient is possible. In this case, the instrument should be carefully inspected after use and discarded when unwinding occurs. Conclusion This instrument allows the removal of gutta-percha canal filling swiftly, thoroughly and safely, transforming this dif- ficult procedure into a more predictable and easier task. Finishing the preparation size and taper varies accord- ing to the anatomy of each clinical case. Clinicians should keep in mind that the size and taper of the selected final shaping file should allow a total elimination of the filling material and the cleaning and shaping of the apical third. This step should obviously be accompanied by abundant irrigation and activation of the irrigants using specifically designed ultrasonic generators and tips such as Endo Ultra (COLTENE MicroMega). Thorough cleaning and shaping complete the retreatment procedure, facilitate the 3D ob tu- ration and promote a successful root canal therapy outcome. Prof. Walid Nehme is a clinical professor in the department of endodontics of Saint Joseph University of Beirut in Lebanon, where he received his DDS in 1988 and MSc in 1994. His academic activities lie in undergraduate and postgraduate education in endodontics and focus on clinical training and practice and supervision of research projects. He runs postgraduate endodontic courses and hands-on courses in the Middle East, Africa, Europe and Canada. Prof. Nehme works in a referral-based practice limited to endodontics in Beirut and Abu Dhabi in the UAE. He is an analyst and opinion leader for clinical trials for endodontic manufacturers and has contributed to the development of new files and devices in endodontics. He has published scientific and clinical articles in peer-reviewed journals nationally and internationally on such subjects as root canal anatomy, instrumentation techniques, NiTi files, irrigation procedures, obturation and retreatment. He is a fellow of the International College of Dentists, an international member of the American Association of Endodontists, a council member of the Asian Pacific Endodontic Confederation, a founder member and a past president of the Arab Endodontic Society, and a past president of the Lebanese Society of Endodontology. contact Prof. Walid Nehme Space 2 Center New Jdeiden Street Beirut Lebanon walidnehmeendo@gmail.com roots 3 2020 35

6 9a industry report | 7 8 Fig. 6: After the core build-up. Fig. 7: After preparation of teeth #11 and 21 for a veneer and crown, respectively. Fig. 8: Lithium disilicate restorations. Figs. 9a–c: Result after treatment: intra-oral view (a); extra-oral view (b & c). 9b 9c was made to do an endodontic retreatment and re- store tooth #21 with a glass fibre post, core build-up and crown. A veneer on tooth #11 was planned as well in order to correct the shape and create sym- metry. ment errors, as all steps and components are optimally adjusted to each other. Acknowledgement The author would like to thank master dental technician Roberto Della Neve for his diligent work. For the post and core build-up, GRADIA CORE (GC) was chosen. The reason why GRADIA CORE was cho- sen is that it is a dual-cure composite that can be used as a luting cement and for a core build-up. Because of the thixotropy of the material, it easily retains its shape during the build-up. However, during insertion of the glass fibre post (Fig. 5), shear thinning occurs, which makes the material more fluid and easily adapted to the shape of the root canal. When the post space was prepared, an apical seal of 5 mm was left (Figs. 3 & 4).1 The universal adhesive G-Premio BOND (GC) was used in conjunction with GRADIA CORE. Inside the root ca- nal, it was mixed with the dual-cure activator (G-Premio BOND DCA, GC) to ensure proper polymerisation over the entire depth. After the build-up, both central incisors were prepared (Figs. 6 & 7) for treatment with lithium disilicate resto- rations (Fig. 8). The end result was aesthetically pleasing: the restorations were fully integrated into the surround- ings, and the patient was very satisfied with the appear- ance of her new smile (Figs. 9a–c). Conclusion A post and core build-up often entails a multitude of treatment steps. With GRADIA CORE, the luting and build-up material are contained in one product, simpli- fying the procedure considerably and minimising treat- References 1 Abramovitz L, Lev R, Fuss Z, Metzger Z. The unpredictability of seal after post space preparation: a fluid transport study. J Endod. 2001 Apr; 27(4):292–5. doi: 10.1097/00004770-200104000-00016. about Dr Giancarlo Pongione obtained his DDM from the University of Rome Tor Vergata in Italy in 1991 and his PhD on the biocompatibility of dental materials from the University of Siena in Italy. Currently, he has private practices in Naples in Italy and Rome, specialising in aesthetic adhesive restorations and endodontics. In the past, he was a visiting professor at the Sapienza University of Rome. He has authored more than 90 articles on endodontics and aesthetic dentistry and has lectured at numerous national and international congresses. Dr Pongione is an active member of the Bio-Emulation Group, Italian Society of Endodontics and Società Italiana di Odontoiatria Conservatrice (Italian society of conservative dentistry), and a certified member of the European Society of Endodontology. roots 3 2020 37

manufacturer news | Dedicated configuration for any clinic ACTEON X-Mind prime family expands The ACTEON X-Mind prime range has been extended with two new cephalometric configurations, the X-Mind prime 2D-CEPH and the X-Mind prime 3D-CEPH, expanding the fields of applica- tion of the device to orthodontic analysis and improving diagno- sis and treatment planning. The line can now offer a dedicated reference integrated in the ear rod ensure quick and precise patient positioning. Its patented collimation system allows up to 17 different cepha- lometric program selections, including new reduced size modes, which ensure a perfect assessment of the region of interest at the lowest radiation dose. X-Mind prime CEPH continues the tradition of the unmatched ease of use of the X-Mind prime product line, thanks to the user-friendly interface of its virtual control panel, which leads the user through all of its functions in just a few simple steps. The use of a state-of-the-art digital sensor, combined with the high performance of ACTEON Imaging Suite software, ensures superior image quality. configuration for any clinical need, from the most basic pan- oramic image only to the most complete panoramic/CBCT/ cephalometric one, guaranteeing a state-of-the-art implemen- tation of the internal technology and presented in the stylish and compact design which characterises the whole range. Premiered in September 2020, the new CEPH configurations now complete the ACTEON X-Mind prime family and retain the same key concepts of the other members. X-Mind prime devices are designed to fit any environment with their minimalistic and compact design, which, combined with their outstanding ease of operation, provides the operator and patient with the best examination experience available. The unique innovative and effortlessly mounted solution, com- bined with a lightweight framework and a compact footprint, make X-Mind prime CEPH one of the easiest and most complete extra-oral solutions for any dental practice. The new cephalostat, specifically designed for optimising patients’ comfort and stability, and the smart Frankfurt plane www.acteongroup.com roots 3 2020 39

Cell type atlas New research may expedite regenerative dentistry Understanding of cell types and the mechanisms of dental growth is essential for the reconstruction and engineering of teeth. There- fore, researchers from Karolinska Institutet in Stockholm have investigated the cellular composition of growing and non-growing mouse and human teeth. They believe that the new data on the cellular make-up and growth of teeth could accelerate develop- ments in regenerative dentistry and in the treatment of tooth sensitivity. Even though major tooth cell types have long been identifi ed, the spectrum of various tooth cells and stem cells, their differentiation, and the interactions that enable tooth growth remain poorly understood. Teeth develop through a complex process in which soft tissue, with connective tissue, nerves and blood vessels, is bonded with three different types of hard tissue into a functional body part. to gnawing, making this model attractive for studies of stem cell generation, cell differentiation and injury-induced regeneration. Using a single-cell RNA sequencing method and genetic tracing, the researchers examined the characteristics of growing mice incisors, compared them with non-growing mice molars and evaluated the extent to which the mouse model refl ects the growth of human teeth. In this manner, the researchers at Karolinska Institutet, in collaboration with the Medical University of Vienna in Austria and Harvard University in the US, identifi ed and character- ised all cell populations in mouse teeth, in young growing human teeth and in adult human teeth. In addition, the fi ndings might explain complex aspects of the immune system in teeth and help in understanding the formation of tooth enamel. In contrast to humans, whose teeth are completed before adult- hood, mice and many other species have teeth which continue to grow throughout life. The incisor stem cell population in mice continuously self-renews and replenishes tissue that is lost owing Editorial note: The study, titled “Dental cell type atlas reveals stem and differentiated cell types in mouse and human teeth”, was published online on 23 September 2020 in Nature Communications. news | news | news | news | | | news news news news news news news news news news news news m m o o c c . . k k c c o o t t s s r r e e t t t u u h h S S / / a a r r a a h h c c t t a a w w © AD SPECIFICATIONS SCAN ME roots 3 2020 41

dontists, 7,778 paediatric dentists, 5,790 periodontists and 3,708 prosthodontists, and 426 work in oral and maxillofacial pathology, 827 in public health dentistry, and 144 in oral and maxillofacial radiology.1 This calculation counts a dentist toward each practice area for which he or she holds a degree. For example, a dentist possess- ing degrees in orthodontics and paediatric dentistry is counted in both categories. According to these figures, there were 1,007 dentists with multiple specialty degrees. Nevertheless, although dentists tend to obtain a specialty degree, if we compare the number of general dentists to the number specialists in 2001 and 2017 in the US, there is evident growth in the number of GPs: from 130,775 in 2001 to 156,992 in 2017.1 The most popular specialty in the US is orthodontics, and in 2001, there were 9,265 orthodontists, compared with 10,658 in 2017.1 Since there is no true quality control oversight in dentistry except for our personal ethics, if the patient demands a procedure that the dentist is legally licensed to perform, but technically inexperienced in doing so, yet there is a financial reward for conducting it, the risk of things going wrong is quite high. This begins to explain the fine line between high-risk and low-risk dentistry. The American Academy of Oral Medicine (AAOM) de- veloped a risk assessment that affirms that the patient evaluation process requires inclusion of determination of risk associated with dental treatment, as it is essential for the delivery of safe and appropriate dental care as well as the overall health of the patient. AAOM classifies high- risk treatments according to the patient’s age and the potential for infections and complications, among others.2 Nevertheless, it does not consider the experience of the treating dentist, the technologies that the clinician is using or even the time the dentist has in which to perform the treatment. In dentistry, it is my understanding that the higher the degree of complexity of treatments you carry out, the more technology and materials you need, and the more experienced and trained your team must be. For this reason, most clinics that offer high-end dentistry usually have a large team and invest significantly in technology and materials. 1 Fig. 1: Use of platelet-rich fibrin to accelerate wound healing after extraction and to avoid alveolitis. be taken on lightly and requires a great deal of train- ing and technology. No matter how simple a procedure might be, I consider this field to be high risk. There are so many things that can go wrong, and the fact that in many cases the surgeon is not the one doing the restorative work can lead to complications. All it takes is poor posi- tioning of the implant to really create a huge headache for the restorative team. When things go wrong, who is to blame? Restorative work too is high risk, but thankfully, digital technologies are here to provide better solutions to this problem with guides and immediate preoperatively milled temporary restorations. Complex root canal therapy usually requires a microscope, expensive rotary instruments and a highly trained profes- sional, and it can sometimes take many hours to ensure Once you move into the realm of dental aesthetics, you are entering into an emotional relationship with your patient; unless you are able to deliver what the patient desires, you will encounter complications down the road. It requires an expert cosmetic dentist and a great dental technician to ensure that the patient is happy. I consider most complex aesthetic dental work in the anterior area to be high risk in nature. 2 Implant dentistry has been growing in double digits for years, around the globe. It is not something that should Fig. 2: Use of dental dam isolation and ozone therapy to guarantee elimination of any bacteria. roots 3 2020 43

practice management | “I believe that the development of technologies will help and assist GPs and less skilled dentists to perform high-quality dentistry.” Of course, also included are any other procedures that have little impact for the patient or the dentist if things go wrong and for which arising problems can be eas- ily remedied. I see so many simple restorations create such huge headaches due to rushed treatment and a poor protocol. Nevertheless, although complex risky procedures should be performed by highly trained dentists, nowadays, with the development of new technologies in the dental field, it is easier to perform high-quality complex dentistry even if you are a GP without a specialty degree. One the one hand, it is important to understand that it requires time to learn how to use technologies in the dental practice and manage costs, and dentists should not consider a quick training session from a sales person to be the same as a proper accredited course. On the other hand, the dentist’s experience and knowl- edge as well as the application of high-quality materials at the right time can be influencing factors in the per- formance of dental treatments, making them more or less risky. One example is the placement of a crown or bridge, even if it is out of the aesthetic zone. This is a common procedure that has all the risk factors. If the dentist knows how to employ a minimally invasive approach, such as Pascal Magne’s,3 using high-qual- ity materials, has the requisite time for treatment and works with a great laboratory, what would otherwise have been considered a high-risk treatment would then be a low-risk one. 5 To sum it all up, I believe that the development of tech- nologies will help and assist GPs and less skilled den- tists to perform high-quality dentistry. Things are rapidly progressing, and artificial intelligence is coming to help us better diagnose and plan. Yet, for those like myself who are managing teams and trying to get the best out of each clinician, from the planning of a treatment se- quence, which is key to achieving perfect results, we can now rely on the cloud to help us work with teams in other parts of the world, and delegate responsibilities by en- suring that the quality of the treatment plan is perfect. I believe that, if dentists work in teams, surrounded by good materials and technology, they can work more safely and practise higher-quality dentistry as a standard. It is up to universities to ensure that the ethical bound- aries of business practice and dental practice are never blurred. Science and dentistry must always win over pure profit, and a well-managed team can do both. Editorial note: A list of references is available from the publisher. contact Dr Miguel Stanley Rua Dr. António Loureiro Borges, ed. 5, 1º Andar Arquiparque Mirafl ores 1495-131 Algés Portugal info@whiteclinic.pt roots 3 2020 45

practice management | about the situation you’re in before you start to speak. Allow yourself time to consciously breathe in order to balance yourself and take control of the interaction. Envision yourself as the conductor of an orchestra who is responsible for making the individual players follow your desired path. It is vital that you never ever engage in a discussion or start treatment on a patient if you are angry about him or her, or about the situation involving this particular patient. 2. Don’t take anything personally Rude or impolite patients are mostly angry with them- selves, rather than with you—their dentist. Remember that it is only human to project one’s self-discontent onto others. Whatever these patients say to you, it is most likely something that only has more to do with them- selves, rather than with you or with something you might have done wrong. Here’s a trick: try to imagine these pa- tients as being physically very small before and during your encounter with them. In this way you will be able to take control of situations like these more efficiently. 3. Be proactive Be sure to send out the treatment protocols of rude pa- tients immediately after having finished their treatment sessions. Here’s why: usually, these types of patients have issues with trust. Being rude or impolite is often only a protective shield protecting them from being hurt or disappointed. It is therefore vital to do everything you can in order to make them feel safe, and to show them that they have no reason to be suspicious. 4. Be brave, be vocal! If patients are being rude to you—be brave and call them out on it! Figure out what could be the worst possible scenario while assessing the situation. With this risk man- agement tip, you will immediately be able to acknowledge the fact that you could master any arising circumstance. Express your feelings verbally and tell your patient that he or she is being rude to you. You might be surprised about how ignorant the other person is towards the en- tire situation. Listen to what they have to say in defence. Show empathy and react with phrases like ‘I understand you’, instead of saying ‘you are right’. It would be a pity to not see the forest for the trees! 5. Be calm and humane Good interpersonal skills are essential for building last- ing relationships. Therefore, always speak the truth with- out letting hurt feelings get in your way. Try to get to the bottom of a concrete issue by asking your patient ques- tions, sit down with him or her and work out a solution that works for the both of you. A true win-win situation. At the end—make a gesture. For instance, offer your pa- tient a warm handshake to show your positive attitude towards resolving the problem and departing with him or her on good terms. How easy was that, right? Use the above-mentioned steps as a protocol in your daily practice and you will soon notice that you are in con- trol again and have greater peace of mind. With these five steps at your disposal, you will know exactly how to re- solve a difficult problem and how to establish a customer- oriented service culture. In addition, I am confident that— if implemented correctly—these tips will help you achieve a significant increase in income. Just try it and feel free to share your thoughts with me! I am sure that you are looking forward to the next issue of roots magazine with great anticipation, where in the fourteenth part of this series I will take a deep dive into yet another fascinating topic, namely: how to reject a patient (politely) without putting the reputation of your practice in jeopardy as a consequence. I will present you with the five most important steps that will help you remain calm and balance your stress levels. Until then, remember that you are not only the dentist at your clinic but also its manager and leader. In case you have any questions or requests, if you would like to have further information on this topic, or if you simply need guidance in solving certain situations, don’t hesitate to get in touch by e-mailing me at dba@yiannikosdental.com or visit our website, www.dbamastership.com. I am looking forward to our next step towards business growth and educational development. Let’s keep in touch! Part XII of this series: “Turning medical tourists into loyal patients” will appear after the restrictions related to the ongoing global pandemic are lifted. about Dr Anna Maria Yiannikos (DDS, LSO, M.Sc., MBA) is one of the first two women worldwide to have obtained a master’s degree in laser dentistry. She has owned a dental clinic for 30 years now and leads the innovative Dental Business Administration Mastership Course at RWTH Aachen University in Germany. She is an adjunct faculty member of the Aachen Center for Laser Dentistry. contact Dr Anna Maria Yiannikos Adjunct Faculty Member of AALZ at RWTH Aachen University Campus, Germany DDS, LSO, M.Sc., MBA dba@yiannikosdental.com www.dbamastership.com roots 3 2020 47

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THE THE ACE RACE LEGACY LEGACY SAFE. EFFICIENT. SOFT CONTROL. www.fkg.ch/race-evo RECIPROCATION REDEFINED SAFE. EASY. MINIMALLY INVASIVE. www.fkg.ch/r-motion