Implant Tribune Middle East & Africa No. 6, 2023

PUBLISHED IN DUBAI www.dental-tribune.me Vol. 13, No. 6 Im m ediate or delayed loadin g in the fu lly edentu lou s m a xilla By Drs Yassine Harichane, Rami Chiri & Benjamin Droz Bartho- let, France Although scientiﬁ c and techni- cal advancements have been made in the ﬁ eld of dentistry, there are still many patients who are either partially or fully edentulous. Eden- tulism has a negative impact on both dental and general health, leading to physical problems like the inability to eat normally and mental health issues such as a de- crease in self-esteem. Oral implantology has made tremendous progress, allowing pa- tients to have clinical outcomes similar to natural dentition. Im- plant-supported prostheses pro- vide edentulous individuals with daily satisfaction, enabling them to enjoy food and social interactions.1 When a single tooth or multiple teeth are lost, ﬁ xed solutions are suggested, whereas in the case of complete edentulism, the patient can choose between an overden- ture or a ﬁ xed complete denture on implants. The McGill consensus state- ment recommends an overdenture supported on two implants as the ﬁ rst choice for the edentulous mandible. Numerous protocols de- scribe technical aspects of implant surgery and prosthetic restoration, whether in immediate or delayed loading. While the McGill consen- sus statement considers a conven- tional tissue-supported denture for the maxilla to be problem-free, some patients may wish for a more comfortable solution to improve their dental health. Can we oﬀ er them a maxillary implant solution that is supported by scientiﬁ c re- search? Can patient management be improved by modifying implant placement and loading protocols? These are the two questions we will aim to answer with the aid of recent scientiﬁ c literature. Fig. 1: Maxillary anatomical obstacles. Fig. 2: Maxillary prosthesis on axial and tilted implants. 3 Fig. 3: All-on-4 and All-on-6 prostheses. Fig. 4: Surgical guide and dynamic navigation. Surgical steps In implant surgery, considering anatomical obstacles is crucial. Re- garding the maxilla, the nasal cavity and maxillary sinuses pose chal- lenges, while in the mandible, the inferior alveolar nerve and mental foramen can be problematic (Fig. 1). ▶ Page C2 Fig. 5: Implant loading timeline. Fig. 6: Patient satisfaction timeline.

C2 ◀ Page C1 The two areas also diﬀ er regarding bone density, the maxillary bone usually being less dense than that of the mandible. To overcome ana- tomical obstacles like the maxillary sinus, either axial implants can be placed after a sinus lift or zygo- matic implants can be placed to by- pass the obstacle (Fig. 2).2,3 Many implant designs have been devel- oped to provide satisfactory pri- mary anchorage, regardless of bone density. Brånemark’s work in oral im- plantology established success cri- teria that have become standard in implant practice. Scientiﬁ c research has enabled advancements in oral implantology, such as immediate placement after extraction proce- dures for single or multiple teeth in both the maxilla and mandible. While the McGill consensus recommends statement an overdenture on two implants for the mandible, there is no estab- AD lished consensus for the maxilla. This lack of consensus is due to the heterogeneity of results and the diﬃ culty of conducting systematic reviews on the subject. However, Malò et al. have pushed the clinical boundaries of maxillary implant treatment with the All-on-x proce- dure (Fig. 3), which is demanding but eﬀ ective and satisfying for pa- tients.4 Digital workﬂ ows have also im- proved surgical protocols through static guides and dynamic naviga- tion (Fig. 4). Static guides involve planning the implant position in software and reproducing it in a surgical guide, while dynamic navi- gation allows for real-time adjust- ments based on CBCT imaging during surgery, providing greater precision5. Prosthetic steps Brånemark recom- mended allowing several months initially IMPLANT TRIBUNE for implants to heal, but current literature supports the possibility of immediate load- ing, whether for a single implant or multiple implants in the maxilla or mandible (Fig. 5). Research has validated immediate loading in fully edentulous maxillae, whether using conventional or zygomatic implants, with high success rates. However, certain condi- tions need to be considered.3 This accelerated-care approach has prevented patients from experiencing dis- abling edentulism and has been shown to improve their overall satisfaction and oral health-related quality of life. Studies have found that implant-supported overden- tures can improve the general well-being of edentulous patients, and ﬁ xed implant prostheses are even more eﬀ ective (Fig. 6).1 The eﬀ ectiveness of immediate loading of implants is comparable to that of de- layed loading, although the evidence is not strong enough to make a deﬁ nitive clinical recommendation. Studies have shown that there is no statistically signiﬁ cant diﬀ erence in survival rates between immediate and delayed loading of implants and prosthe- Implant Tribune Middle East & Africa Edition | 06/2023 ses. However, it is worth noting that early implant failure in the maxilla is quite common, with half of the failing implants being lost within the ﬁ rst six months. This is often attributed to poor bone quality in the maxilla.2 Patients may be more satisﬁ ed with a functional ﬁ xed prosthe- sis regardless of the time of loading, but there is limited evidence to support this. Prosthesis instability may also contribute to dif- ferences in loading times. For example, one study showed no dif- ference in patient satisfaction between immediate and delayed loading after three months, although patients in the delayed-load- ing group had relined provisional restorations. At 12 months, pa- tient satisfaction levels were similar, suggesting that the percep- tion of the prostheses does not change much over time. Studies have shown that patients have an excellent level of satisfaction with immediate loading, and the protocol is generally well toler- ated with careful preoperative, perioperative, and postoperative management.6 Recent research has expanded the indications for zygomatic implants, which oﬀ er suﬃ cient primary stability but may still be susceptible to lateral forces that can cause implant fracture. This is particularly problematic in clinical cases in which the maxillary ﬁ xed prosthesis opposes natural mandibular dentition. One pos- sible solution is to use a hybrid prosthesis on a bar.3 Marginal bone loss data indicates a loss of 1.67mm for the maxilla after ten years, regardless of the type of implant used. However, a more pronounced loss was observed around implants supporting acrylic prostheses than those supporting ceramic prostheses, beginning at the ﬁ fth year of follow-up. This under- scores the importance of surface polishing to reduce plaque build-up when using acrylic prostheses.2 Conclusion Dynamic navigation is a promising technique that allows for precise implant placement in fully edentulous patients. Zygomatic implants are a reliable and predictable option for maxillary reha- bilitation.3 The existing literature provides limited evidence on the com- parative eﬃ cacy of immediate versus delayed loading of implants. Evidence supports the eﬀ ective use of immediate loading for ﬁ xed complete dentures without the need for augmentation. Immedi- ate loading and ﬁ xed hybrid restorations are the most commonly used methods for their rehabilitation. However, delayed loading and bar overdentures are also eﬀ ective and well tolerated by pa- tients. Patients seem to be at least as satisﬁ ed with immediate loading, and clinical complications may be comparable to those of delayed loading. The choice of immediate loading should be based on the practitioner’s expertise in providing such treatment and on patient selection. Editorial note: This article was ﬁrst published in implants international ma- gazine of oral implantology, Vol. 24, Issue 2/2023. Please scan this QR code for the list of references. Dr Yassine Harichane graduated from the former Paris Descartes University in France and conducted a number of research projects there. He is an author of numerous publications and a member of the cosmetic dentistry study group at the University of Paris. He can be contacted at yassine.harichane@gmail.com. Dr Rami Chir holds a DDS and is in private practice in France. Dr Benjamin Droz Bartholet holds a DDS and is in private practice in France.

Implant Tribune Middle East & Africa Edition | 06/2023 C3 IMPLANT TRIBUNE Extra-shor t and u ltra-shor t im plants in tran screstal sinu s lift with autologou s bone obtained from dr illin g as graftin g m ater ial Retrospective study By Dr Eduardo Anitua, Spain Introduction Sinus elevation, both through the lateral approach and the transcr- estal approach, is one of the most widely used techniques for the reha- bilitation of the posterior maxillary area with dental implants when this area is atrophic in height.1-3 Both techniques have a long history with multiple publications in the interna- tional literature that endorse their use, with success rates for implants placed by both methods of 96.9% success when placed directly (at the same time as the elevation proce- dure) and 97% when placed after the height recovery process (in the case of lateral sinus elevation exclusively).4 In most of the articles that analyze the indications for each of the two surgical procedures—transcrestal or lateral elevation—they recommend the use of the conventional lateral window when there is less than 5 mm of residual bone height or the exist- ing bone volume presents low den- sity with diﬃ culty in stabilizing the dental implant. In the rest of the sit- uations, transcrestal elevation would be indicated, there being therefore a range of clinical cases where both techniques would be indicated.1-8 If both techniques are indicated, it is usual to select the one that presents the least morbidity for the patient, which is why the transcrestal eleva- tion technique is gaining importance nowadays. In order to make its use increasingly safe and predictable, the neoalveolar genesis protocols have been modiﬁ ed (diﬀ erent drill- ing protocols and drills) as well as the morphology of the implants and their surface, allowing better primary stability in more extreme situations and faster integration for more com- plex cases.9-12 Our study group has described a variation of the conventional transcr- estal elevation technique described by Summers in 199413 in which a bio- logical drilling procedure (at low rev- olutions) is used to create the alveo- lus where the implant will be placed, and the ﬁ nal portion of the sinus ﬂ oor is removed using a front cutting drill.10,12,14-16 This drill is atraumatic and allows gradual wear of the sinus cortex with a low risk of perforation of Schneider's membrane. Further- more, both procedures, when per- formed at low revolutions without ir- rigation (normal and cortical drilling), allow us to harvest all the bone dis- lodged from the crest to subse- quently form a particulate bone graft, which can sometimes even be the only graft material to be placed in the elevation, embedded in PRGF-Endoret14 from the time of har- vesting. With this procedure based on the density of the receptor bed, the morphology of the implant, and a meticulous analysis of each clinical situation, the placement of ex- tra-short implants has been achieved by means of transcrestal elevation in residual bone height of less than 5 mm, which is the limit recom- mended by most studies for using this procedure, without renouncing the predictability of treat- ment.10,12,15,16 In the following retrospective study, the survival of extra-short (5.5 and 6.5 mm) and ultra-short (4.5 mm) implants inserted using the previously described transcrestal el- evation technique, with autologous bone obtained from drilling as the only grafting material, was assessed as the main variable. As secondary variables, mesial and distal crestal bone loss after loading and the maintenance of bone volume achieved at the implant apex after loading were assessed. the Material and methods We reviewed retrospectively the clinical histories of patients undergo- ing transcrestal sinus lift with the in- sertion of extra-short and ultra-short implants with autologous bone ob- tained from the drill itself as grafting material in the period between No- vember 2019 and November 2021. The data were collected in a data col- lection notebook for subsequent statistical analysis, the main variable of the study being the survival of the implants placed using this technique, and the secondary variables being the measurement of crestal bone loss (mesial and distal), bone gain at the apex of the implant, and its main- tenance after functional loading of the implant. Diagnostic and surgical proto- col All patients were studied prior to implant insertion by means of diag- nostic models, intraoral exploration, and a dental CT scan (Cone-beam) subsequently analyzed using speciﬁ c software (BTI-Scan III). Prior to im- plant insertion, antibiotic pre-medi- cation consisted of amoxicillin 2g orally one hour before surgery and paracetamol 1g orally (as an analge- sic). Subsequently, patients were treated with amoxicillin 500-750 mg orally every 8 hours (according to weight) for 5 days. The implants were placed by the same surgeon, using the biological drilling technique, at low revolutions, without irrigation, collecting all the bone and keeping it in PRGF-Endoret (fraction 2 without activation) until it was used as a particulate graft for transcrestal elevation.10 The ﬁ nal milling of the sinus cortex is carried out with the frontal cutting drill (de- signed for this technique, as de- scribed above), which allows us to re- move the ﬂ oor of the maxillary sinus by progressive wear without damag- ing Schneider's membrane. Once the membrane is accessible through the crestal perforation, it is carefully re- moved with a blunt instrument that allows the graft and the implant to be placed without generating exces- sive pressure on it. Once this maneuver has been carried out, the implant is inserted with the surgical motor set at 25 Ncm and 25 rpm, ﬁ nalizing the insertion of the implant with the torque spanner. The drilling is adapted to achieve correct primary stability, considering the density of the area and the resid- ual bone volume. The implant slowly lifts the membrane as it is inserted into the neo-alveolus and contains between the apex and the mem- brane the bone graft which will be the volume to be increased added to the total length of the implant. Follow-up visits Patients are subsequently seen for intraoral radiographs with a con- trol parallelizer, and the necessary measurements are taken on these radiographs to check the stability and crestal bone loss of the implants. Once the radiograph was obtained in digital format, it was calibrated using speciﬁ c software (Digora for Win- dows, SOREDEX Digital Imaging sys- tems) through a known length in the radiograph such as the dental im- plant. Data collection was carried out by two independent examiners. Statistical analysis Medical records were reviewed to obtain demographic, social, pres- ence of parafunctions, and medical data of interest. The implant was the unit of analysis for descriptive statis- tics in terms of location, implant di- mensions, and radiographic mea- surements. The patient was the unit of measurement for the analysis of age, sex, and medical history. A Shapiro-Wilk test was per- formed on the data obtained to ver- ify the normal distribution of the sample. Qualitative variables were described by frequency analysis. 1 Fig. 1: Implants included in the study according to diameter and length. The po- sitions of the inserted implants varied from second premolar to third premolar. 2 Fig. 2: Positions of the implants included in the study, where we observe that the right and left ﬁ rst molars and the right second molar are the most frequent. 3 Fig. 3: Bone type and different lengths of residual ridge with a similar distribution in both groups. Quantitative variables were de- scribed by mean and standard devi- ation. Implant survival was calculated using the Kaplan-Meier method. The diﬀ erence between the apical bone volume at the time of surgery (sum of implant and bone graft over the apex) and the ﬁ nal bone volume after loading was compared using a Student's t-test. Data were analyzed with SPSS v15.0 for Windows (SPSS). Statistically signiﬁ cant diﬀ erences were considered to exist when p<0.05. Results Seventeen patients were re- cruited, and 25 implants were in- serted that fulﬁ lled the above-men- tioned inclusion criteria. Forty-eight percent of the patients were female, and the mean age of the study group was 56 +/- 13.35 years. The length of the implants included in the study the most was 6.5 mm in 12% of cases, 5.5 mm in 12% of cases, and 4.5 mm in 76% of cases. The diameter ranged from 2.5 mm to 6 mm maximum diameter, with frequent being 4.75 mm in 36% of cases, followed by 4.25 mm in 24% of cases. All the diam- eters of the implants analyzed ac- cording to their length (Fig. 1). The most commonly rehabilitated posi- tions were 16, 17, and 26, each ac- counting for 28% of the cases. The re- maining positions with their fre- quency (Fig. 2). The mean bone height of the re- sidual ridge was 4.34 mm (+/- 0.78), with a range between 3.18 and 6.37 mm in the sample. The bone type was III in 52% of the cases and IV in the remaining 48%. The height distribu- tion between the two bone types was ▶ Page C4

C4 ◀ Page C3 IMPLANT TRIBUNE Implant Tribune Middle East & Africa Edition | 06/2023 very similar (Fig. 3). The mean inser- tion torque of the implants was 26.20 Ncm (+/- 15.69). All implants were rehabilitated in two surgical stages, using screw-retained pros- theses with transepithelial, bridging at least 2 units. The mean crown/im- plant ratio for all implants was 2.44 (+/- 0.41). The mean follow-up of the loading was 13.5 months (+/- 3.2), and no adverse events were encountered during this time, with 100% implant survival. implants after The mean crestal bone loss of all implants studied was 0.29 mm (+/- 0.59), and the mean distal bone loss was 0.30 mm (+/- 0.61). When an- alyzing the bone volume above the apex at the mesial level of the apex, a mean gain of 1.29 mm (+/- 0.59) and at the distal level of the apex of 1.30 mm (+/- 0.61) were obtained, with a total mean of 0.90 mm (+/- 0.76). This in- crease remains stable one year after loading in 60% of the cases and de- creases on average in the remaining cases by 0.30 mm mesially after load- ing for one year and 0.45 mm distally (+/- 0.51), with the variation not being statistically signiﬁ cant (p=0.686 for mesial and p=0.142 for distal). The evo- lution of bone volume over the apex at the initial insertion and after one year of loading (Fig. 4). Figures 5-11 show one of the cases included in the study. Discussion Short and extra-short implants have become a routine technique for the rehabilitation of edentulous maxillary posterior sectors. When comparing the insertion of these im- plants with other larger diameter im- plants (for which regenerative tech- niques with greater morbidity are generally necessary), it is found that there is no statistically signiﬁ cant dif- ference in implant survival (P=. 24; RR:1.35; CI: 0.82-2.22), nor in crestal bone loss (P=.06; MD: -0.20; CI: -0.41 to 0.00) nor in surgical (P=.08; RR:0.54; CI: 0.27-1.09) and prosthetic (P=.92; RR:0.96; CI: 0.44-2.09) compli- cations between the two groups, ac- cording to a meta-analysis focusing on this topic.17 In many cases, these implants can be inserted directly, without ac- cessory techniques, but when the re- sidual bone volume is below the minimum dimension of the implant available, we can use them in con- junction with small trans-alveolar sinus lifts, a procedure of proven ef- ﬁ cacy in the international litera- ture.14-16,18-19 When we choose to in- sert these implants, we are generally faced with a residual ridge with ex- treme resorption, so the main diﬀ er- entiating factor that will mark the success of our treatment will be to achieve the initial stability necessary for implant integration. The achievement of primary sta- bility in these cases in which we per- form a transcrestal elevation with ex- tra-short and/or ultra-short implants where bone density is generally very low generally involves seeking ves- tibulo-palatal and mesio-distal bi- corticalisation. To achieve this, a thorough study of the density of the area and the insertion of implants with large diameters rather than lon- 4 Fig. 4: Length of implants with apical bone height achieved with crestal elevation and their progress at one year of loading. Fig. 8: Post-surgical image of the insertion of both implants and the increased bone volume on the implants immediately after surgery. Fig. 9: Image of progressive loading of the implants six months after insertion. This loading is performed with a hinged bar structure and a resin prosthesis, screwed on transepithelial. Fig. 5 & 6: Planning of two of the implants located in the left sinus to be placed with transcrestal elevation, where we can see the low residual bone volume of 2-3mm. Fig. 10: Image of the deﬁ nitive prosthesis after loading at one year follow-up, with no incidences or bone loss in either implant. Fig. 7: Transcrestal elevation technique with autologous particulate as graft ma- terial. As can be seen, we perform a low-speed drilling where all the autologous bone is harvested and kept in PRGF-Endoret until it is used. Subsequently, the bone is inserted once the membrane has been raised and ﬁ nally the implant. Fig. 11: A periapical X-ray at three years shows the bone over the apex of the im- plants, being greater in the case of the implant in position 26 in the distal area and equally so in the implant in area 27. ger lengths is used, as the portion of the implant that is placed inside the sinus in the transcrestal elevation will not provide us with a gain in inser- tion torque or load distribution.16,20 In this study, the insertion torque was not very high at 26.20 Ncm (+/- 15.69), which is usual considering that all the implants were placed in areas of low density (type III and IV bone) and with ridges with excessive resorption. Even so, the three-di- mensional positioning and the cor- rect choice of implant allowed us to achieve a 100% success rate, with no failures in the initial osseointegration or in the one-year follow-up after loading. During this follow-up pe- riod, some of the implants have even shown not only apical consolidation of the graft but also a small increase in the graft, which leads us to believe that the technique used has favored bone proliferation around and on the implant. The material used for transcr- estal elevation was autologous bone obtained from milling in 100% of the implants studied, which makes its in- tegration easier thanks to its capacity for osteoinduction and osteocon- duction, which is even more favored when it is mixed for use with PRGF-Endoret as we have done in this study, which is why we also be- lieve that despite being borderline situations, the grafts have func- tioned as expected in all cases. transmission of The maintenance of the bone volume achieved in elevation and its increase in some cases is largely de- termined by the initial consolidation and loads through the implant.25,26 For this rea- son, in the cases shown, we have opted for screw-retained prosthe- ses, with intermediate elements (transepithelial) and with a ﬁ rst pro- gressive loading phase as shown in the clinical images, which gradually transfers the tension and then ends with the deﬁ nitive prosthesis. the Conclusion Extra-short and ultra-short den- tal implants inserted by means of transcrestal sinus lift with biological drilling and the use of a front cutting drill, adapting the drilling to the re- cipient bed, have proved to be highly predictable in this series of cases. Even so, further studies with im- plants of similar characteristics and recipient bed qualities as those in this study are needed to be able to extrapolate the results obtained more widely. Editorial note: The list of references is available upon request from the publis- her. Eduardo Anitua is a doctor of medicine and surgery, specializing in stomatology, who runs a research laboratory. When asked why he dedi- cates part of his time to research, he always answers that he is fortunate to be able to develop and focus his creative capacity within his professi- on. It is a privilege that he ﬁ nds fun, motivating, and fulﬁ lling.