PUBLISHED IN DUBAI www.dental-tribune.me July-August 2018 | No. 4, Vol. 8 “He brought a world of enthusiasm and knowledge to the global endodontic community” SUBSCRIBE NOW https://me.dental-tribune.com/e-paper/ issn 2193-4673 Vol. 13 • Issue 4/2017 roots international magazine of endodontics 42017 dontic meetings together. Fred was a character, but in the best sense of the word. He was entertaining, charming and unpredictable. That was Fred. But to those of us who knew and loved him, he was much more than that. He was a loyal friend who made a maximum effort to understand each of us in a personal and support- ive way. Really, at the end of the day, Fred was a mensch. He will be very much missed.” Weinstein was born in 1939 in Win- nipeg, Manitoba. He graduated from the University of Manitoba at the age of 22 with a degree in general den- tistry, and then he went on to study endodontics at the University of Pennsylvania School of Dental Medi- cine in Philadelphia, under the tute- lage of Dr. Louis Grossman, known as the “Father of Endodontics.” After receiving his Certiﬁcate in Endodon- tics from the University of Pennsyl- vania in 1969, he moved his family to Vancouver and established an ofﬁce in the Fairmont Medical Building, where he would go on to practice for more than 40 years. “He loved his patients, and he equal- ly enjoyed teaching and lecturing throughout the world to advance the learning within dentistry,” his family wrote in an obituary published in the Vancouver Sun. Weinstein’s accomplishments with- in the profession were notable. He served as an assistant clinical profes- sor at the University of British Co- lumbia and was a past president of the Canadian Academy of Endodon- tics, the British Columbia Society of Endodontics, the Interspeciality So- ciety of British Columbia and the In- ternational Federation of Endodontic Associations (IFEA). He was a mem- ber of the Royal College of Dentists, and he was a fellow of the American College of Dentists and the Interna- tional College of Dentists. Fred Weinstein, DMD, MRCD(C), FICD, FACD, who passed away Oct. 15, 2017, at the age of 78, is pictured in Anaheim, Calif., at the California Dental Association meeting, CDA Presents the Art and Science of Dentistry, in 2012. A retired endodontist from Vancouver, British Columbia, Weinstein often traveled to dental meetings to keep his knowledge of the specialty current and to visit with his many friends. (Photo/Fred Michmershuizen, Managing Editor of DT America) By Fred Michmershuizen, USA He will be remembered as a friend, a teacher and a healer. Fred Weinstein, DMD, a retired endodontist from Vancouver, British Columbia, died Oct. 15, 2017, at the age of 78, after a brief illness. His fellow specialists expressed sadness at his passing and acknowledged how his passion for the profession rubbed off on them through many decades of friendship. Many are also remembering him for his ability to have fun — especially when it came time to promote an international endodontic conference hosted in his native country. “Fred has been an inspiration for me for all these years, ever since we met over 30 years ago,” said Gerald N. Glickman, DDS, MS, professor and chair at Texas A&M College of Den- tistry in Dallas, one of many endo- dontists who shared fond memories of Weinstein. “What a remarkably kind and in- sightful individual he was — always inquiring about me and others and never letting on about himself,” Glickman remembered. “He brought a world of enthusiasm and knowl- edge to the global endodontic com- munity. I will miss him dearly.” “Fred was that special kind of person who would do anything he could to help out when needed. He cared for everyone and was a dear friend,” said John J. Stropko, DDS, of Prescott, Ariz. “Fred was a teacher, always encourag- ing others to use the latest technolo- gy to deliver better treatment results for their patients. During the process, he went to great lengths to clearly communicate his beliefs in an easy- to-understand manner. Our specialty has lost one of its great members.” “I knew Fred for more than 25 years, and I always found it entertaining to be in his company,” said Anne Lau- ren Koch, DMD. “We went to hockey games, basketball games and endo- Dr. Fred Weinstein with ‘Queen Elizabeth,’ at the IFEA meeting in 2007. (Photo/Fred Michmershuizen, Managing Editor of DT America) Dr. Fred Weinstein in Hamburg, Germany, in the summer of 2017. (Photo/Fred Michmershuizen, Managing Editor of DT America) research Photodamage of dental pulpa stem cells during 700 fs laser exposure case report Apexiﬁcation treatment with MTA REPAIR HP interview Understanding sonic-powered irrigation He served on advisory boards for sev- eral leading dental manufacturers, and he lectured extensively through- out the world. He also served as a volunteer endodontist at the 2010 Vancouver Winter Olympics, and performed root canal treatment on world boxing champion Sugar Ray Leonard in the 1980s. He was especially proud to have served as the general chairman for the 2007 IFEA World Congress in Vancouver. To drum up excitement for that meeting, he dressed as a Royal Canadian “Mountie” at several events leading up to it — something that friends and colleagues remem- bered for years. “Fred always had a smile and was known as ‘the Canadian Mountie’ for his outﬁt that he wore at every dental meeting to promote the IFEA meeting in Vancouver in 2007,” re- membered Samuel O. Dorn, DDS. “He was truly dedicated to the Cana- dian Academy of Endodontics and its place in global endodontics. His pas- sion for endodontics and his friend- ship will never be forgotten.” “I cherish my photo of us with him dressed as a Mountie when he was president of IFEA,” said Dr. William Ben Johnson. “Fred and I started out as endodontic colleagues, then be- came friends. So much so he would go snow skiing with me even when he didn’t care for skiing, and I would drink wine with him when I preferred scotch. I’ve lost a friend.” After his retirement from practice, Weinstein continued to travel to den- tal meetings to keep his knowledge of the specialty current and to visit with his many friends. For many years, Weinstein was edi- tor in chief of roots magazine, the international C.E. magazine of endo- dontics, published by Dental Tribune America. “Above all of Fred’s accomplish- ments and titles, his family remained his number one priority in his life, always,” his family wrote in the Sun. “He had a gentle heart of gold, com- passion and sincerity and a smile that would illuminate a room.”
A2 ENDO TRIBUNE Dental Tribune Middle East & Africa Edition | 4/2018 MTA placement with the Produits Dentaires (PD) MAP System By Dr. Mauro Amato, Switzerland More than 20 years ago, Torabi- nejad et al. (1993) ﬁrst described a new root-end ﬁlling material called mineral trioxide aggregate (MTA). MTA showed in vitro better sealing ability than amalgam or Super EBA when used as a root-end ﬁlling mate- rial. Later, several in vivo and in vitro studies demonstrated more applica- tions for MTA. Pulp capping, apexi- ﬁcation, repair of root perforations and root-end ﬁlling are commonly described clinical procedures to seal the pathway of communication be- tween the root canal system and the external surface of the tooth. The ap- plication of MTA was ﬁrst described as being achieved with aid of plastic or metal spatulas (Torabinejad and Chivian 1999). Unfortunately, prop- er placement was not possible in this manner. Therefore, Produits Dentaires intro- duced a universal carrier system for clinical and surgical MTA placement. Its Micro-Apical Placement (MAP) System offers different application points for every clinical situation. The Intro Kit and the Universal Kit are for orthograde obturation and the Surgical Kit for retrograde ob- turation. The NiTi Memory Shape tips can be manually shaped to any required curvature. After autoclave sterilization, the needle returns to its initial shape. With the use of the MAP System, proper placement of MTA has become an easy task for every dentist. In combination with the MAP Sys- tem, Produits Dentaires offers a white MTA specially developed for placement with the MAP System. The optimized practical size means economical application for each treatment. There are many indica- tions for the PD MTA White, and with the MAP System, proper placement is easy in every situation. Pulp capping Vital pulp therapy has become more popular in recent years. Calcium hy- droxide has been the most common material for pulp capping, but MTA has shown even better results in bio- compatibility and outcome (Aguilar and Linsuwanont 2011). Cases with large carious pulp exposure can be treated successfully with partial pul- potomy and MTA as a capping agent, keeping teeth vital (Figs. 1a–e). MTA may save compromised teeth (Mente et al. 2014) (Figs. 3a–e). Apexiﬁcation In order to prevent extrusion of root canal ﬁlling material in imma- ture teeth with open apices, MTA is used as an apical plug. The results of many studies have shown that MTA induced apical hard tissue formation more often and its use was associ- ated with less inﬂammation than with other test materials (Simon et al. 2007) (Figs. 2a–g). Apical surgery MTA is the material with the most fa- vorable outcome as a root-end ﬁlling material for apical surgery. MTA has been associated with signiﬁcantly less inﬂammation, cementum for- mation over MTA and regeneration of the periradicular tissue (Torabine- jad and Chivian 1999) (Figs. 4a–f). Repair of root perforations Accidental perforation of the pulp chamber or of the root canal signiﬁ- cantly changes the prognosis of the tooth. Perforation repair with a bio- compatible sealing material such as Dr. Mauro Amato is a lecturer and re- searcher at the department of periodon- tics, endodontics and cariology of the Uni- versity of Basel in Switzerland. Dr. Amato is a committee member of the Swiss So- ciety for Endodontology. He can be con- tacted at firstname.lastname@example.org Figs. 1a–e: (a) Deep carious lesion. (b) Partial pulpotomy. (c) MTA application with the MAP System and PD MTA White. (d) Filling. (e) Post-op radiograph showing the pulp capping with MTA. Figs. 2a–g: (a) Endodontically treated tooth with ﬁstula. (b) After retreatment, the tooth showed an open apex. (c) MTA application with the MAP System and PD MTA White. Condensation of the MTA with pluggers (d) or paper points (e). (f) MTA plug. (g) Post-op radiograph showing the MTA plug and the reconstruction with a ﬁber post. Figs. 3a–e: (a) Radiolucency in the cervical part of the canine. (b) Bleeding from the perforation. (c) MTA application with the MAP System and PD MTA White.(d) Original canal and repair of root perforation. (e) Post-op radiograph showing the root canal ﬁlling. Figs. 4a–f: (a) Pre-op radiograph with a large periradicular lesion. (b) Periapical surgery. (c) MTA application with the MAP System and PD MTA White. (d) Condensation of the MTA with pluggers. (e) Mirror view of the root-end cavity ﬁlled with MTA. (f) Post-op radiograph showing the root-end ﬁlling.
Dental Tribune Middle East & Africa Edition | 4/2018 ENDO TRIBUNE A3 Preservation of root cementum: A comparative evaluation of power-driven versus hand instruments By Bozbay E, Dominici F, Gokbuget AY, Cintan S, Guida L, Aydin MS, Mariotti A, Pilloni A., Italy Background Grzesik et al. suggested that cemen- tum plays an important regulatory role in periodontal regeneration. One of the major goals of periodontal treatment is the removal of patho- genic micro-organisms by scaling and root planning. In the past the misconception was to obtain a root surface with smooth and hard sur- face characteristics that was free of endotoxins which resulted in the re- moval of the subgingival plaque and calculus deposits, and the removal of all or most of the cementum. Recent studies have reported that endotoxins were not located within cementum and removal of ‘diseased’ cementum was not necessary for a successful periodontal treatment. Saygin et al concluded that preser- vation of cementum on the root surface was necessary for new attach- ment and as a source of growth fac- tor. Hence non-aggressive removal of cementum is essential for optimal periodontal health and regeneration. Ultrasonics with new shaped tips and subgingival air polishing devices has been developed for removal of root accretions with minimal root damage. Air polishing has been sug- gested as a treatment modality for root debridement resulting in prob- ing depth reductions and removal of subgingival bioﬁlm. No scientiﬁc evi- dence exists today showing the loss of root substance or surface rough- ness produced by either ultrasonics or Air polishing. Aim To assess the amount of cementum remaining following in vivo root in- strumentation as well as the surface characteristics of the retained ce- mentum Material and Methods - 48 caries free, single-rooted teeth in 27 patients diagnosed with severe chronic periodontitis with periodon- tal probing depth (PPD) ≥5 mm in at least two sites per tooth with radio- graphical bone loss of more than two thirds of root length and scheduled for extraction were included in this study - Teeth were randomly divided into four treatment groups: Instrumenta- tions were performed with medium power settings 1. Piezoelectric ultrasonic scaler - (Air- Flow Master Piezon, Instrument Tip PS; EMS SA)-U 2. Piezoelectric ultrasonic scaler - (Air- Flow Master Piezon, Instrument Tip PS; EMS SA) followed by air polishing with the glycine powder (Air-Flow Powder Perio, Perio-Flow Nozzles; EMS SA) - U + AP 3. Air polishing with the glycine pow- der (Air-Flow Powder Perio, Perio- Flow Nozzles; EMS SA) - AP; 4. Hand instruments (Gracey curettes 5/6, 11/12, 13/14 American Eagle, Mis- soula, MT, USA)-HC Treatment - One approximal root surface of each tooth was randomly subjected to debridement, and the other ap- proximal surface was used as control. - Following instrumentation, the teeth were immediately extracted traumatically and analyzed with a dissecting microscope - Remaining calculus, root surface roughness and loss of root substance were evaluated along with scratches, gouges, cracks, and any other chang- es in the cementum that was present were noted. Results Remained cementum: - Percentage of coronal cementum remaining following subgingival in- strumentation was 84% for U, 80% for U + AP, 94% for AP and 65% for HC. - The amount of retained cementum with AP was signiﬁcantly greater than with HC. SEM - Smoothest root surfaces were pro- duced by the HC followed by the AP - Coronal and apical sections showed that AP produced the least amount of cementum loss and therefore the greatest retention of residual cemen- tum - Root surfaces instrumented by U or U + AP presented grooves and scratches. Time taken to complete root instru- mentation - Shortest time taken was using AP and the longest time was with U + AP. - AP required 31% less time for root preparation in comparison to HC, whereas U + AP needed 30% more time Conclusions - Air polishing was signiﬁcantly more effective and superior in preserving cementum. - Hand instrumentation using cu- rettes was most effective in remov- ing cementum in comparison to ul- trasonics or hand instruments www.ifea2018korea.com The 11th International Federation of Endodontic Associations IFEA 2018 Seoul October 4lThul -7lSunl, 2018 Coex, Seoul, Korea Endodontics : The Utmost Values in Dentistry Overview W www.ifea2018korea.com www.facebook.com/ifea2018seoul Confirmed Invited Speakers Paul Abbott Australia Andreas K. Braun The Netherlands Filippo Cardinali Italy Is there still a role for medicaments in endodontics? Root resorption after dental trauma - findings and treatment possibilities Solutions to simplify shaping and cleaning: improving the quality of the root canal treatment Antonis Chaniotis Gustavo De-Deus Greece Brazil Franck Diemer France Management of severe curvatures and complex anatomy with controlled memory files: A new approach The relationship among reciprocation, glidepath and canal scouting How asymmetric geometry and heat- treatment influence the behavior of rotary root canal instrument Samuel O. Dorn Gianluca Gambarini USA Italy Nick Grande Gianluca Plotino Italy Extraction-Replantation: An alternative surgical technique 3D endodontics: Shaping root canals in 3 dimensions The paradox of minimal invasive endodontics Mo K. Kang USA Syngcuk Kim USA Anil Kishen Canada Pulp tissue regeneration: Challenges and new outlook Long term prognosis of endodontic Tx vs. Implant Tx Nanomaterials in endodontics: A potential game changer Sergio Kuttler USA Seung Jong Lee Francesco Maggiore Korea Italy “Past, present and future of endodontic files”: Where science meets technology Are the viable cells the only predictor for delayed replantation? Soft tissue management in endodontic microsurgery Tara Mc Mahon Belgium Zvi Metzger Israel Does heat treated NiTi facilitate endodontic therapy? Early diagnosis and biomechanics of vertical root fractures Yosef Nahmias Canada How to prevent instrument breakage by creating a mechanical reproducible glide path (don’t rotate, reciprocate) Cliff Ruddle USA Frank Setzer USA Hagay Shemesh The Netherlands Endodontic Disinfection: 3D Irrigation Management of iatrogenic errors by non-surgical and surgical retreatment. A realistic look at root canal fillings. Trends, evidence and clinical performance. Michael Solomonov Israel Asgeir Sigurdsson USA Ibrahim Abu Tahun Jordan Contemporary approaches to instrumentation of non-round root canals Is it toothache? non-odontogenic pain presenting as dental pain Re-establishing biological order in reengineering the pulp-dentin complex Yoshi Terauchi Japan Martin Trope USA Ghassan Yared Canada Predictable and minimally invasive method to retrieve a separated file The expanding role of vital pulp therapy Management of second mesio-buccal, narrow and curved canals with only one reciprocating instrument. Lecture titles are tentative and subject to change.
A4 ENDO TRIBUNE Dental Tribune Middle East & Africa Edition | 4/2018 Top performance Flexible NiTi ﬁle HyFlex EDM performs well internationally Full control in the dental practice As an established Endo provider, COLTENE has been working closely with leading dentists, universities and endo experts for many years. The multitude of sophisticated treatment aids, ranging from spe- cially hardened instruments to bio- active obturation materials, reﬂects the self-image of the Swiss innova- tion leader. True to the company’s motto “Upgrade Dentistry”, the COLTENE service team regularly asks practice owners and endodon- tic specialists about their wishes for even more conﬁdent work in virtu- ally all situations. This also formed the basis for the development of the production process called “Electri- cal Discharge Machining” (EDM for short) by the dental manufacturer’s renowned R&D department, which ultimately gave the exceptionally break-resistant ﬁles their name. The practice-oriented Endo offer is com- plemented by a large number of ap- plication-related workshops, train- ing materials and personal services. Further product information: https://hyﬂex.coltene.com/ HyFlex EDM File Sequence By Coltene In the course of two major interna- tional events in the dental industry, Swiss dental specialist COLTENE interviewed over 130 dentists and Endo experts about their experi- ences with its latest NiTi ﬁle system. The results of the product tests are more than impressive: 98% of the participants would continue to use the HyFlex EDM for the treatment of their endodontic cases, even after the tough test. The necessary cutting edge Every two years, both the Interna- tional Dental Show in Cologne (IDS for short) and the Congress of the Eu- ropean Society for Endodontics (ESE Congress) serve as an international platform for professionals with an interest in endodontics to exchange experiences between colleagues. Thus, both events in 2017 provided the ideal occasion for a large-scale test campaign for the latest NiTi ﬁle generation from COLTENE. Selected dentists and joint practices through- out Europe were given the oppor- tunity to put the ﬂexible HyFlex EDM’s ﬁle system through its paces. 76% of the participants particularly praised the high ﬂexibility that leads to good adaptation in the canal. The pre-bendable ﬁles work reliably in all the lengths and sizes currently available on the market without dis- placing the centre of the canal. Like the proven HyFlex™ CM ﬁles, the HyFlex™ EDM ﬁles also possess the so-called “Controlled Memory“ ef- fect and are distinguished by their high level of ﬂexibility. In contrast to classic NiTi ﬁles, they have almost no recovery effect and can be pre- bent. As a result, the ﬁles move per- fectly through the centre of the ca- nal, which signiﬁcantly reduces the risk of ledging, transportation and perforation. During autoclaving, they recover their original shape so that they can be reused safely until a visible break in their spiral struc- ture clearly indicates the end of their service life. At the same time, the in- novative manufacturing process by means of spark erosion contributes to the high breakage resistance of the HyFlex EDM ﬁles, particularly under heavy-duty use. In fact, Hy- Flex EDM ﬁles are up to 700% more resistant to cyclic fatigue compared to traditional NiTi ﬁles. A special combination of material surface and tapering allows a signiﬁcant reduction in the number of ﬁles used without compromising the preservation of the natural root ca- nal anatomy. These smart features were also evaluated positively in the test and the dentists use the robust high-performance instruments pri- marily for cases where they want to produce reliable results quickly with a reduced number of ﬁles. Additional ﬁles sizes allow- ing more ﬂexible application Due to limited access endo experts often want more ﬂexibility from their instruments. Pre-bendable tools can extend the horizon into new dimensions. Particularly in a limited working space, modular nickel-titanium systems display their full strength. With a total of seven highly ﬂexible ﬁle variants, COLTENE offers a wide-ranging Hy- Flex NiTi program. In addition to the usual lengths of 25 mm, all prepara- tion ﬁles of the popular EDM series are also available in 21 mm working length. The application of the more agile, shorter models is particularly recommended in of the posterior molars and in patients with cranio- mandibular problems. The new HyFlex EDM 20/.05 prepa- ration ﬁle augments the existing HyFley EDM line. The additional ﬁle enables fans of the ﬂexible NiTi range to treat curved channels only with the efﬁcient EDM ﬁles. After creating a glide path with the Glide- pathﬁle 10/.05, the new ﬁle with the same taper allows minimally inva- sive, fast preparation of the canal. Subsequently the actual shaping can be done in the usual manner with the universal ﬁle HyFlex EDM One- File, size 25. Depending on the chan- nel anatomy, apical preparation can be ﬁnished with EDM ﬁles up to ISO size 60. Even in these large sizes the ﬁles work safely and without trans- portation of the canal center.
Dental Tribune Middle East & Africa Edition | 4/2018 ◊Page A6 Case 1: Male (born 5 June 1987): Tooth 35 ENDO TRIBUNE A7 Fig. 3a: 18 March 1997 ante pulpotomy. Fig. 3b: 18 March 1997 post pulpotomy Fig. 3c: 6 May 2005 status from the ﬁles of the practice exam- ined in this study in the years 1985 through 2006. Treatment method was the so-called N2 method accord- ing to Sargenti and Richter(1954), which meant: no canal rinsing and application of the paraformalde hyde-containing N2. Rubberdam was not used. The N2 powder contained 7% formaldehyde before admission by the EU, afterwards the content was decreased to 5%. Four cases were excluded: · A non-vital case where the initial X-ray did not clearly reveal whether the apical radiolucency of both roots were a matter of apical periodontitis or apical papilla. · A VitA-case was extracted alio loco a few days up to 18 months after VitA. · X-ray was insufﬁcient in the third case, VitE of an upper molar · In the fourth case, the patient did not show up again after devitalization of an upper premolar. Thus, 95 cases to be judged remained, of which only two non-vital teeth were treated in a two-stage therapy. 93 cases were treated in one appoint- ment inclusive deﬁnite ﬁlling. For root canal ﬁlling, the N2 powder was mixed with N2 liquid to a creamy tex- ture, a harder consistency was needed for VitA. N2 application for root canal ﬁlling was done by lentulo, for VitA a carrier instrument was used to bring the material into the excavated pulp cavity up to 1–2mm into the canal ac- cesses. The 95 anonymous made cases were clinically followed-up without recall at an average of 73 months after treat- ment. 75 cases underwent X-ray con- trol (follow-up X-ray) after an average of 70 months; 64 cases as single-tooth X-ray in parallel technique and 11 cas- es as orthopantomogram. Judged as endodontic failure were: pain or ﬁstula at treated tooth, de- velopment of apical periodontitis, lingering or newly developed apical periodontitis. Treatment success of the 75 cases was analysed in two modes considering the questions: · Did apexiﬁcation/apexogenesis oc- cur? · Did the apex remain unaffected of apical periodontitis? In multi-rooted teeth with different apical diagnosis, the worst diagnosis was assumed as being valid for the tooth. A double magniﬁer served as diagnostic aid. Three persons evalu- ated the X-rays independently from each other: The doctoral candidate (author AJ), a dentist with ten years of professional experience and the prac- tice owner (author RT). The ﬁnal diag- nosis resulted from the consensus of the three ratings. Statistic signiﬁcance was assumed for an error assumption of p < 0.05 for comparison of two parameters and calculated by means of the logrank test. Result The average age of the patients was 10.7 years (6–25). Most cases (N=54) were attributed to mandibular mo- lars (72 %), among these mostly the ﬁrst lower molars with 48 cases (50.5 % of the cases to be analyzed), fol- lowed by nine cases of maxillary incisors. 75 cases were subject to one or—in intervals—multiple follow-up X-rays. 40 teeth (53.3%) were extirpat- ed vitally, 28 teeth (37.3%) were ampu- tated vitally and seven non-vital teeth (9.3%) underwent conservative endo- dontic treatment. Post-endodontic clinical control averaged at 73 months (12–271), the follow-up X-rays to be evaluated at 70 months (10–228). In 41 cases, X-ray evaluation was done more than 48 months after endodon- tic therapy. ÿPage A8 Your Choice for Professional Obturation and Repair Therapies Game Changer. Solution for Simple, Precise and Predictable MTA Placement. DISCOVER OUR ENTIRE MAP RANGE AT WWW.PDSA.CH/MAP Produits Dentaires SA . Vevey . Switzerland
A8 ◊Page A7 Case 2: Male (born 28 December 1980): Tooth 14 ENDO TRIBUNE Dental Tribune Middle East & Africa Edition | 4/2018 Fig. 4a: 18 August 1989 ante vitalextirpation. Fig. 4b: 18 August 1989 post vitalextirpation Fig. 4c: 16 January 2004 status. The longer therapy dated back, the earlier achievement of the treatment aim apexiﬁcation or apexogenesis could be veriﬁed. Two cases featured open apical foramina even 16 respec- tively 30 months post treatment. In nine molars, the apical foramina of various roots were partly still open, partly already closed after an average of 28 months. Thus their results could only be judged as partial success. An average post-observation time of 71 months was registered in 55 cases with the diagnosis ‘apex closed with- out lengthening of the root’. A ‘closed apex with root growth’ could be stat- ed in nine cases after anaverage of 117 months (see case 1) . The average age of the nine young patients with root growth amounted to 9.5 years, those without root growth had an average age of 11.2 years. Overall, an apexiﬁcation success was found in 64 cases (85.3 %, conﬁ- dence interval 77.3–93.3 %). In nine other multi-rooted teeth (12 %), the maturation process of the roots was differently distinct: The same tooth featured a root with closed apical foramen, whereas another root still showed an open foramen. Matura- tion progress of the immature teeth was ob served on the basis of the 49 cases with multiple follow-up X-rays in different intervals. A ﬁrst follow-up X-ray was available after an average of 34.6 months (4–130). 18 cases (36.7 %) featured advancement, whereas the status of the other cases remained unchanged. Not considering the nine partial suc- cesses as mentioned above, an apexi- ﬁcation success rate with/ithout root lengthening of 90 % (conﬁdence in- terval 80.7–99.3%) was determined in the VitE group, the success rate of the VitA group was 85.7% (conﬁdence interval 72.7–98.7%), the non-vital group showed a success rate of 57.1 % (conﬁdence interval 20.5–93.8 %). The percentaged difference of apexiﬁca- tion success VitE versus VitA with a probability of error of p = 0.5893 and VitA versus non-vital group with p = 0.0910 was not signiﬁcant statisti- cally. A statistic signiﬁcance could be determined when comparing VitE with the non-vital group (p = 0.0243). Apexiﬁcation success in root-ﬁlled teeth proved not to be depending on the ﬁlling level (p = 0.2441). Ten endodontic failures (13.3%), nine of which radiographically and one clinically due to ﬁstula formation (see case 2), were observed: six following VitE (15%), two following VitA (7,1%) and two following conservative root canal treatment of the seven non-vi- tal teeth (28,6%). Regarding endodon- tic success/failure of VitE versus non- vital group, a statistic signiﬁcance revealed (p = 0.0587). A statistic sig- niﬁcance could be stated when com- paring VitA with the non-vital group (p = 0.0157). Apexiﬁcation occurred in nine of the ten failures. Patient clas- siﬁcation in age groups of younger than 125 months and older than 125 months was not relevant regarding avoidance of endodontic failure (p = 0.448). 19 teeth (20 % of the 95 treated teeth) were extracted during the observa- tion period. Seven of these teeth belonged to the VitE group, eight to the VitA group and four to the non- vital group. A statistic signiﬁcance of extraction frequency existed when comparing the VitE with the non-vital cases (p = 0.0169). Figure 1 shows the three groups’ probability of survival with the aim of no extraction. Nine teeth (47%) were extracted with- in the ﬁrst 50 months after treatment. The time history of all extractions is featured in Figure 2. Main reason for extraction was damage/fracture of the natural tooth crown (42%) or an endodontic failure (31%). 33 of the 48 endodontic treatments of ﬁrst lower molars had been done prior to the age of ten years. 14 ﬁrst lower molars (73.7 % of all extractions) were extracted, 12 of which prior to the age of 20 years. Discussion The present study is a retrospective one with data collected out of a regu- lar dental practice, where endodon- tic treatments were done according to the Sargenti N2 technique (1954) exclusively, a method not accepted in the established dental doctrine, primarily due to the formaldehyde content in the N2 powder, but also because of elimination of root canal rinsing. 95 cases could be evaluated. Whereas apexiﬁcation literature is generally based on front teeth with necrotic pulp, only 10 % of the 95 evaluated teeth were non-vital (see case 3). 38% were treated by VitA, 52% by VitE. The ﬁrst mandibular molars were represented most with 48 cases. Patient recall did not take place. In contrast to clinics, patient loyalty nev- ertheless allowed a clinical control of all 95 cases, which was done after an average of 73 months. 75 cases were subject to X-ray control. The actually evaluated X-ray had been taken after an average of 70 months. 49 of the 75 cases had more than one follow-up X- ray taken so that X-ray interpretations could have been done for various time intervals thus allowing control of the further apical development. A ﬁrst control X-ray was generally avail- able after 34.6 months. 18 cases of the more than one follow-up X-rays documented a continuous matura- tion. For lack of previous X-rays, the result of 31 cases of ﬁnal apical condi- tion after 34.6 months does not mean that apexiﬁcation or apexogenesis could not have been occurred prior to this time, which could have been clariﬁed in a prospective study only. However, the radiographic observa- tion period of 70 months is long com- pared to other publications. The long- est is indicated by Herforth (1981) with 3.9 years after treatment of 541 front teeth, condition after accident, with calcium hydroxide and Jodoform and with four years by Cvek (1972), who evaluated the data of 328 immature luxated/subluxated maxillary front Case 3: Female (born 8 August 1988): Tooth 11 Fig. 5a: 4 September 1995 ante RCF (non-vital). Fig. 5b: 4 September 1995 post RCF. Fig. 5c: 22 April 2002 status. teeth treated with calcium hydrox- ide by 58 practitioners. 12 months af- ter MTA treatment of 30 single-root, non-vital teeth with open apical fora- men Annamalai and Mungara (2010) obtained the following results: apical healing 100%, apexiﬁcation 86.6 %, root extension 30%. After an observa- tion time of 12–44 months, Holden et al. (2008) determined a success rate of 85 % (N=17) for their 20 teeth treated by MTA in several appointments. The healing and apexiﬁcation process was not subject to recall interval. How- ever, advanced growth of the apices after N2 application over a period of several years could have been well ob- served in the present study (average: without extension 71 months, with extension 117 months), possibly due to the different characteristics of MTA versus N2. The authors Simon et al. (2007) ob- served 43 single- rooted teeth with open apical foramen that had been one-stage treated with MTA for a time of 12 up to 36 months. They stated a complete healing in 65%, an incom- plete healing in 30 % and an ‘apical closure’ in 26 % of these cases (N = 11). The radiographic diagnosis of the present study is: 78.8 % positively without apical periodontitis, 9.3 % apical periodontitis questionable, 12 % apical periodontitis with 85.3 % featuring ‘apical closure’ and 36.7 % root extension. However, a direct comparison between the Simon and the present study is not admissible due to the low number of cases, the different observation periods and the non-coordinated interpretations of the evaluation modalities. El Meligy et al. (2006) examined 30 pulpotomy cases (15 Ca(OH)2, 15 MTA), 24 of which were ﬁrst molars, which suggests a comparison with our study. The following assumptions were applied: no clinical problems, radiographically no apical periodonti- tis, apexiﬁcation occurred. 13 calcium hydroxide cases (87 %), but all MTA cases came up to this. The three above mentioned therapy groups of this study achieved an apexiﬁcation success of totally 85.3 % by means of the formaldehyde- containing N2: 90 % following VitE, 85.7 % following VitA, 57.1 % following conservative root canal treatment of non-vital teeth. The success rate of 57.1 % for non-vital teeth should not be taken too seriously because of the 20.5–93.8 % wide conﬁdence interval due to the small number of cases. The percentaged success referred to the respective teeth as a whole. An- other 12% referred to some molar roots with partly open, partly closed apices. Sheehy and Roberts (1997) comparatively report on the forma- tion of a hard substance barrier after calcium hydroxide application after 5–20 months in 7–100 % of the cases. In contrast, the authors Roberts and Brilliant (1975) considered the inter- pretation of an X-ray as being unre- alistic for determination of a possible apical closure matching the Liang et al. proof of insufﬁcient diagnostics of the periapical X-ray versus digital volume tomography (DVT). 23 teeth were reexamined according to both techniques two years after endodon- tic treatment. 74 % of periapical radio- lucencies could not have been visual- ized with conservative X-ray and 61 % with DVT. Despite of the diagnostic deﬁcits to be assumed, X-ray in com- bination with a clinical examination remains the only practical method. An inter pretation bias in this study can be largely eliminated due to the consensus ﬁnding of the three X-ray evaluators. While in short-term studies with low case numbers extractions are not mentioned, this study counted 19 extractions, 14 of which were allotted to the ﬁrst mandibular molars. Thus the mandibular molars represented 73.7% of all extractions with a 50.5 % share in treatments. This relatively high extraction frequency may be due to the fact that these teeth erupt early as the ﬁrst permanent molars thus having been exposed to tooth- damaging inﬂuences for the longest time. Extraction is avoided less in the posterior area versus the anterior ar- eas, as in young patients the gap nor- mally closes the natural way without orthodontic or prosthodontic treat- ment. Garcia-Godoy and Murray (2012) made up a survey with hints to deﬁ- cits in apexiﬁcation literature. Ac- cording to this survey, 200 case stud- ies on calcium hydroxide had been published. Reports on unfavourable and long-term effects would be miss- ing. One problem of long-term calci- um hydroxide dressings would be an alteration of the mechanical dentine characteristics, which could lead to fractures. Long-term studies regard- ing MTA would be missing. However, for achieving apexiﬁcation, mineral- trioxide aggregate would be more ef- fective than calcium hydroxide. Also regarding regenerative proce- dures, only case studies and case series would exist. The ‘blood clot’ generated during this therapy should however have no contact to the in- serted sealer, as sealers were not bio- compatible and featured a cell-toxic effect. In the present study, pulp tissue, pos- sibly blood as well, had contact to the cell-toxic N2. As the long-term obser- vation showed, this contact had no disadvantageous effect to the respec- tive teeth. Regarding apexiﬁcation and apexogenesis, a perennial study rather proved that the success rate was at least equal to MTA and calcium hydroxide. Root fracture, as suspect- ed in calcium hydroxide cases, could not have been noticed in any of the cases. One-stage treatment has to be considered as special advantage of N2 application aiming at apexiﬁcation, which at the same time is a time- and cost-saving method. Editorial note: A list of references is available from the publisher. Dr Anette Joschko General Dentist, Cologne, Germany Dr Robert Teeuwen General Dentist, Geilenkirchen,Germany Prof. Jerome Rotgans RWTH Aachen University, Medical Faculty, Aachen, Germany