An in vivo comparative clinical and radiographic evaluation of a mixture of zinc oxide-Ocimum sanctum extract, zinc oxide-ozonated oil, and zinc oxide-eugenol as obturating materials in primary molars.

Background: To overcome some of the disadvantages of the current primary root canal obturating materials, there is a continued interest in search for chemical compounds with broader and more effective antibacterial action and less cytotoxicity. Aim: This study aimed to evaluate and compare in vivo the clinical and radiographic success of mixtures of zinc oxide-Ocimum sanctum extract, zinc oxide-ozonated oil, and zinc oxide-eugenol (ZOE) as obturating materials in pulpectomy of primary molars. Settings and Design: This was an in vivo randomized controlled clinical trial. Materials and Methods: Ninety primary molars selected were randomly divided into three groups. Group A was obturated with zinc oxide-O. sanctum extract, Group B with zinc oxide-ozonated oil, and Group C with ZOE. All the groups were evaluated for success or failure based on clinical and radiographic criteria at the end of 1, 6, and 12 months. Statistical Analysis Used: The intra- and inter-examiner reliability of the first and the second co-investigators was calculated by Cohen's kappa statistic. The data were analyzed using Chi-square test, P ≤ 0.05 (indicates statistical significance). Results: By the end of 12 months, the overall clinical success rate was 88%, 95.7%, and 90.9% in Groups A, B, and C, respectively; whereas the radiographic success rate was found to be 80%, 91.3%, and 86.4% in Groups A, B, and C, respectively. Conclusion: On the basis of the overall success rates of all the three obturating materials, the following order of performance can be concluded: zinc oxide-ozonated oil > ZOE > zinc oxide-O. sanctum extract.

Outcome of Endodontic Surgery: A Meta-analysis of the Literature-Part 3: Comparison of Endodontic Microsurgical Techniques with 2 Different Root-end Filling Materials.

INTRODUCTION: The aim of the present study was to investigate the influence of root-end preparation and filling material on endodontic surgery outcome. A systematic review and meta-analysis was conducted to determine the outcome of resin-based endodontic surgery (RES, the use of high-magnification preparation of a shallow and concave root-end cavity and bonded resin-based root-end filling material) versus endodontic microsurgery (EMS, the use of high-magnification ultrasonic root-end preparation and root-end filling with SuperEBA [Keystone Industries, Gibbstown, NJ], IRM [Dentsply Sirona, York, PA], mineral trioxide aggregate [MTA], or other calcium silicate cements). METHODS: An exhaustive literature search was conducted to identify prognostic studies on the outcome of root-end surgery. Human studies conducted from 1966 to the end of December 2016 in 5 different languages (ie, English, French, German, Italian, and Spanish) were searched in 4 electronic databases (ie, Medline, Embase, PubMed, and Cochrane Library). Relevant review articles on the subject were scrutinized for cross-references. In addition, 5 dental and medical journals (Journal of Endodontics; International Endodontic Journal; Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology, and Endodontics; Journal of Oral and Maxillofacial Surgery; and International Journal of Oral and Maxillofacial Surgery) were hand checked dating back to 1975. All abstracts were screened by 3 independent reviewers (H.B., M.K., and F.S.). Strict inclusion-exclusion criteria were defined to identify relevant articles. Raw data were extracted from the full-text review of these selected articles independently by each of the 3 reviewers. In case of disagreement, an agreement was reached by discussion, and qualifying articles were assigned to group RES. For EMS, the same search strategy was performed for the time frame October 2009 to December 2016, whereas up to October 2009 the data were obtained from a previous systematic review with identical criteria and search strategy. Weighted pooled success rates and a relative risk assessment between RES and EMS were calculated. To make a comparison between groups, a random effects model was used. RESULTS: Sixty-eight articles were eligible for full-text review. Of these, per strict inclusion exclusion criteria, 14 studies qualified, 3 for RES (n = 862) and 11 for EMS (n = 915). Weighted pooled success rates for RES were 82.20% (95% confidence interval [CI], 0.7965-0.8476) and 94.42% for EMS (95% CI, 0.9295-0.9590). This difference was statistically significant (P < .0005). CONCLUSIONS: The probability for success for EMS proved to be significantly greater than the probability for success for RES, providing best available evidence on the influence of cavity preparation with ultrasonic tips and/or SuperEBA (Keystone Industries, Gibbstown, NJ), IRM (Dentsply Sirona, York, PA), MTA, or silicate cements as root-end filling material instead of a shallow cavity preparation and placement of a resin-based material. Additional large-scale randomized clinical trials are needed to assess other predictors of outcome.

Cicatrización y reparación ápico-periapical en endodoncia / Apical and periapical healing and repair in endodontics

El objetivo de toda preparación endodóntica es eliminar la mayor cantidad de gérmenes, detritus, restos orgánicos y material descompuesto del canal radicular. En este trabajo se presentan casos clínicos con controles a distancia que van de 9 a 33 años, de conductos tratados al mayor ensanche posible, siempre y cuando la estructura radicular lo permita, intentando no perforar, no descentralizar, no hacer escalones, no deformar, y obturando por ténica de condensación lateral a conos múltiples, con cemento sellador a base de óxido de cinc eugenol y conos de gutapercha. Todos fueron éxitos clínicos y radiográficos...

Comparison of the efficacy of nickel-titanium rotary systems with or without the retreatment instruments in the removal of gutta-percha in the apical third.

BACKGROUND: The purpose of this study was to compare the efficacy of nickel-titanium rotary systems with or without the retreatment instruments in the removal of gutta-percha from the apical third. METHODS: The systems compared were as follows: ProTaper Universal (PT), ProTaper Universal Retreatment (PTr), Mtwo (M2) and Mtwo Retreatment (M2r). Sixty extracted mandibular incisors were treated with a crown-down technique and filled with gutta-percha and sealer. The apical diameter was standardized in 0.30 mm, 1 mm from the apex. The teeth were distributed into 4 experimental groups: PT, PTr, M2 and M2r. In PTr and M2r groups, filling materials were removed by PTr/M2r followed by root canals preparation up to a PT F4/M2 40; in groups PT/M2, the filling materials were removed and the root canals were prepared by PT up to a PT F4/M2 up to a M2 40. The roots were split and photomicrographing. The percentage of clean area in the apical 5 mm was calculated using software. Data were analyzed with the Kruskal-Wallis test. RESULTS: Remaining material was found in all hemisections and there was no statistically significant difference between the groups (p = 0.09). Considering the surface of the canal walls of all teeth, the mean of the percentage of clean area was 54%. CONCLUSIONS: Considering the applied methodology, remaining filling material was found in all hemisections, regardless of the retreatment technique and PT or M2 were as effective as PTr/PT or M2r/M2.

Prognostic factors relating to the outcome of endodontic microsurgery.

INTRODUCTION: The aim of this retrospective study was to evaluate the outcome of endodontic microsurgery and to examine prognostic factors related to healing. METHODS: The clinical records of all patients who had undergone endodontic microsurgery from 1997-2003 at the National Dental Centre of Singapore were examined. Teeth with a recall period of 1-2 years were selected. All surgical procedures, except for flap raising and suturing, were performed under a surgical operating microscope. Root-end cavities prepared with ultrasonic tips were filled with Intermediate Restorative Material (Caulk, Milford, DE) or mineral trioxide aggregate. Teeth were evaluated for clinical signs and symptoms after surgery. Preoperative and postoperative radiographs were evaluated independently by 2 endodontists. RESULTS: Of 243 root-end surgeries performed, 93 were eligible for the study. Outcomes were categorized as healed, healing, or persistent disease; 78.5% of teeth were assessed to be healed or healing, and 21.5% had persistent disease. The percentages of healed and healing teeth for anterior and posterior root-end surgeries were 76.5% and 80.4%, respectively, with no significant difference in the procedures (P = .8). Ordinal logistic regression showed a higher likelihood of healing in females compared with males (P = .001) and maxillary anterior teeth compared with mandibular anterior teeth (P = .03). Preoperative probing depths of ≤3 mm were significantly associated with healing (P = .05). CONCLUSIONS: The use of modern endodontic surgical techniques resulted in 78.5% healed and healing teeth with a recall period of 1-2 years. Prognostic factors affecting successful healing include sex, tooth type, and preoperative probing depths.

A technique to salvage endodontically compromised maxillary anterior tooth.

A complication of endodontic treatment is over-preparation of the tooth structure in an attempt to access calcified pulp chambers and root canals. This could result in thin root walls that might compromise the long-term prognosis of the tooth. There are various treatment options when such a complication occurs, among them, extraction of the compromised tooth and its replacement with a dental implant. This clinical report describes a nonsurgical, multidisciplinary treatment alternative where a maxillary anterior tooth with a thinned root wall was successfully saved by repairing the damaged root to its original thickness using a composite resin material and subsequently restoring with a cast post and core and a crown.

Comparison of clinical outcomes of endodontic microsurgery: 1 year versus long-term follow-up.

INTRODUCTION: The purpose of this study was to examine and compare the clinical outcome of endodontic microsurgery after 1 year of follow-up and over a period of 4 years. METHODS: The database of the Department of Conservative Dentistry, Yonsei University, Seoul, South Korea, was searched for patients who had undergone endodontic microsurgery and had been evaluated 1 year after surgery and over a period of 4 years. Two examiners independently evaluated the postoperative radiographs taken 1 year after surgery and over a period of 4 years using Rud's criteria. To analyze and compare the success rate based on the observation period, the McNemar test was performed with a significance level of 0.05. RESULTS: The study included 115 cases. Using Rud's criteria, the overall success rate of cases with 4 or more years of follow-up was 87.8% compared with 91.3% at 1 year of follow-up. There was no significant difference between the follow-up periods (P = .344). CONCLUSIONS: There was no significant difference in the clinical outcome after endodontic microsurgery when comparing 1-year follow-up periods with longer follow-up periods.

Success of root fillings with zinc oxide-ozonated oil in primary molars: preliminary results.

AIM: To evaluate the success rate of mixture of ozonated oil and zinc oxide as a primary teeth root filling material. STUDY DESIGN: Prospective randomised clinical study. METHODS: The study included 60 infected primary mandibular molars which were equally divided into study group (ozonated oil-ZnO) and control group (zinc oxide-eugenol). Pulpectomy procedure was performed and the children were followed at regular intervals. All the children were available for evaluation at the end of 12 months. The teeth were evaluated for success or failure based on clinical and radiographic criteria by a blinded investigator. STATISTICS: The proportional values were compared using χ(2) test. RESULTS: Clinical and radiographic evaluation suggested that teeth obturated with ozonated oil-zinc oxide demonstrated good success rate (93.3%) as compared to zinc oxide eugenol (63.3%). However, no statistically significant variation (p = 0.408) was observed between the groups. CONCLUSION: Ozonated oil-ZnO demonstrated a good clinical and radiographic success at 12 months follow-up and it can be considered as an alternative obturating material in infected primary teeth.

Effect of indomethacin on surface treatment and intracanal dressing of replanted teeth in dogs.

PURPOSE: This study evaluated the healing process of teeth replanted after root treatment and intracanal dressing with indomethacin alone or indomethacin with calcium hydroxide (Ca[OH]2). MATERIALS AND METHODS: Through a case-control study, 24 teeth of 6 adult dogs were extracted, dried, and divided into 4 groups according to the root surface treatment protocols performed before replantation and the intracanal medication used after replantation. In group 1 (negative control), root surfaces were treated by immersion in a 0.9% saline solution and then replanted. In the other groups, the roots were immersed for 10 minutes in Ca(OH)2 (group 2), indomethacin (group 3), or a solution of indomethacin and Ca(OH)2 (group 4). After 2 weeks, group 1 teeth were subjected to single-visit root canal treatment and obturation with gutta-percha and sealer consisting of zinc oxide and eugenol. The teeth in the other groups were subjected to intracanal dressing with the same material used for immersion. After an additional period of 28 weeks, the animals were euthanized and the jaws containing the replanted teeth were processed for histologic analysis. Histometric values were statistically analyzed, with significance set at a P value less than or equal to .05. RESULTS: Group 1 exhibited significantly more normal periodontium than group 4 (P = .02). Total resorption was greater in group 4 than in group 1 (P = .02). No statistically significant difference in the percentage of surface resorption or in total inactive resorption was observed between the groups. CONCLUSIONS: The findings of this study suggest that intracanal dressing and topical root treatment with Ca(OH)2 with or without indomethacin is not recommended for teeth dried for 50 minutes, but the use of indomethacin alone as root surface treatment for delayed tooth replantation deserves further study using longer drying periods. In addition, the present results suggest that a single-visit root canal, performed up to 2 weeks after replantation, might be indicated for teeth dried for up to 50 minutes.

Prognostic factors of clinical outcomes in endodontic microsurgery: a prospective study.

INTRODUCTION: This prospective study examined the potential prognostic factors of endodontic microsurgery and compared the predictors of an isolated endodontic lesion with those of both an isolated endodontic lesion and an endodontic-periodontal lesion. METHODS: Data were collected from the Microscope Center of the Department of Conservative Dentistry at the Dental College of Yonsei University, Seoul, Korea, between March 2001 and March 2011. A total number of 584 teeth were included, and all clinical procedures were performed by a single operator (E.K.). The evaluation was performed at least 1 year after surgery. For statistical analysis of the predisposing factors, the chi-square test and logistic regression were performed. RESULTS: Of the 584 cases treated, 431 cases came for recall after a period of at least 12 months. Sex (female), tooth position (anterior), arch type (maxilla), and lesion type (isolated endodontic lesion) were found to have a positive effect on surgical outcome. With regards to isolated endodontic lesions, the tooth position (anterior), arch type (maxilla), and type of restoration (single/splinted crown, short bridge, and removable partial denture abutment) were found to be pure positive predictors. CONCLUSIONS: In endodontic microsurgery, it is likely that preoperative factors, particularly the tooth position and arch type, have a greater influence on the healing outcome than intra- and post-operative factors.

A survey of endodontic practices among dentists in Nigeria.

AIM: To investigate the pattern of routine endodontic practices among Nigerian dentists. MATERIALS AND METHODS: This study was a questionnaire-based survey of samples of dentists in the Nigerian cities of Enugu and Benin. The self-administered questionnaire contained 25 close-ended questions with multiple choice options. The data collected included demographic details of respondents, root canal preparation techniques, irrigants and intracanal medicaments used, the number of appointments, method of working length determination, root filling techniques, cements used, and the scope of treatment performed. RESULTS: Most respondents used sodium hypochlorite as the irrigant, the step back technique for canal preparation, and lateral condensation with a zinc oxide-eugenol-based sealer for obturation. Most respondents did root canal treatment on all types of teeth and used radiographs to determine the working length 70% of the time. Most respondents followed up their patients for less than 12 months and most treated teeth with periapical areas larger than 10 mm by root canal therapy combined with apical surgery. CONCLUSION: Most Nigerian dentists use step back technique for canal preparation and lateral condensation for obturation. CLINICAL SIGNIFICANCE: Endodontic practice by Nigerian dentists differs from some established practice quality guidelines in many other countries, particularly in nonperfusion of modern techniques into practice, popularity of antibiotic use for endodontic emergencies and a high rate of perforations.

Are referred inaccessible human primary molar teeth really inaccessible?

Despite a body of compelling evidence pertaining to the root canal accessibility of primary teeth, the number of referrals for inaccessibility of primary molars is considerable. The aim of the present study was to evaluate the prevalence of true and false primary molar inaccessibility among subjects who had been referred by general and pediatric dentists. We examined 199 primary molars in 156 patients (87 males, 69 females) aged 3-7 years who were referred by 215 general and 35 pediatric dentists. Problems related to inaccessibility were recorded for each tooth and any individual canal. One hundred seventy-five inaccessible teeth (87.9%) were successfully rehabilitated to accessible status (P < 0.001). The most frequent cause of inaccessibility was an inappropriate access cavity (42.3%), followed by difficult canals (32.6%) and orifice calcification (25.2%). The tooth most frequently reported as inaccessible was the maxillary first molar (40.2%), and that least frequently reported was the mandibular second molar (11.6%). The distobuccal canal of the maxillary first molar and the mesiolingual canal of the mandibular first molar were the most commonly inaccessible canals (P < 0.001). Only 1 out of 8 teeth referred as inaccessible was truly inaccessible. It seems that root canal inaccessibility is mostly attributable to lack of expertise among individual practitioners.

Periapical tissue response after use of intermediate restorative material, gutta-percha, reinforced zinc oxide cement, and mineral trioxide aggregate as retrograde root-end filling materials: a histologic study in dogs.

PURPOSE: To investigate the periapical tissue response of 4 different retrograde root-filling materials, ie, intermediate restorative material, thermoplasticized gutta-percha, reinforced zinc oxide cement (Super-EBA), and mineral trioxide aggregate (MTA), in conjunction with an ultrasonic root-end preparation technique in an animal model. MATERIALS AND METHODS: Vital roots of the third and fourth right mandibular premolars in 6 healthy mongrel dogs were apicectomized and sealed with 1 of the materials using a standardized surgical procedure. After 120 days, the animals were sacrificed and the specimens were analyzed radiologically, histologically, and scanning electron microscopically. The Fisher exact test was performed on the 2 outcome values. RESULTS: Twenty-three sections were analyzed histologically. Evaluation showed better re-establishment of the periapical tissues and generally lower inflammatory infiltration in the sections from teeth treated with the intermediate restorative material and the MTA. New root cement on the resected dentin surfaces was seen on all sections regardless of the used material. New hard tissue formation, directly on the surface of the material, was seen only in the MTA sections. There was no statistical difference in outcome among the tested materials. CONCLUSIONS: The results from this dog model favor the intermediate restorative material and MTA as retrograde fillings when evaluating the bone defect regeneration. MTA has the most favorable periapical tissue response when comparing the biocompatibility of the materials tested.

Long-term effectiveness of four pulpotomy techniques: 3-year randomised controlled trial.

A pulpotomy is the therapy for management of pulp exposures due to caries in symptom-free primary molars. The aim was to longitudinally compare the relative effectiveness of the Er:YAG laser, calcium hydroxide and ferric sulphate techniques with dilute formocresol in retaining symptom-free molars. Two hundred primary molars in 107 healthy children were included and randomly allocated to one technique. The treated teeth were blindly reevaluated after 6, 12, 18, 24 and 36 months. Descriptive data analysis and logistic regression analysis accounting for multiple observations per patient by generalised estimating equation were used. Additionally, various influences including tooth type, upper and lower jaws, type of anaesthesia, operator and the final restoration on treatment success were evaluated (Wald chi-square test). After 36 months, the following total (considering clinical and clinically symptom-free radiographic failures) and clinical success rates were determined (in percent): Formocresol 72 (92), laser 73 (89), calcium hydroxide 46 (75), ferric sulphate 76 (97). No significant differences were detected between formocresol and any other technique after 36 months. However, the odds ratio of failure appeared to be three times higher for calcium hydroxide than for formocresol. No significant differences in total success rates were seen regarding the aforementioned influencing clinical parameters. The correct diagnosis of the pulpal status, bleeding control and the specific technique are highly important for long-term success of pulpotomies in primary molars. According to the presented long-term data, pulpotomies using ferric sulphate revealed the best treatment outcome among the used techniques, while calcium hydroxide resulted in the lowest success rates after 3 years. Therefore, we can recommend ferric sulphate for easy and successful treatment of primary molars with caries-exposed pulps.

Periodontal ligament fibroblast response to root perforations restored with different materials: a laboratory study.

AIM: To compare the effect of several materials on the attachment of periodontal ligament (PDL) fibroblasts to experimentally perforated root surfaces. METHODOLOGY: Root specimens (size 5 × 5 mm) were obtained from extracted human molar teeth and perforations with a 1 mm diameter were created. One group was kept as a control and the rest were repaired with the following materials: Amalgam, Dyract, IRM, Super Bond C&B and Mineral trioxide aggregate (MTA). PDL fibroblasts were placed at a density of 8 × 10(4) cells on the root specimens, incubated on tissue culture inserts (48 h) and then transferred to 48 well-plates. MTT assays were performed at 48 and 96 h for PDL fibroblast survival. Cell attachment was observed using confocal microscopy on days 2 and 5. Total RNAs from the root specimens were isolated on day 5 and type I collagen (COL I) and Runt-related transcription factor 2 (Runx2) mRNA expressions were checked using Quantitative-Polymerase Chain Reaction (QPCR). For the MTT assay and QPCR, one-way analysis of variance (anova) and Tukey HSD multiple comparison tests were used to compare the groups. RESULTS: Mineral trioxide aggregate resulted in a significantly higher cell density (P < 0.001). Dyract, IRM and Super Bond C&B groups had a lower cell density when compared with the control and MTA groups at 48 h (P < 0.001). Confocal microscopy revealed that, among the experimental groups, the MTA group had the largest viable cell population over the restoration site when compared with the other materials; however, reduced cell attachment was noted in all groups when compared with the control. Increased Runx2 mRNA expressions were noted in MTA (P < 0.001) and IRM (P < 0.01) groups when compared with control and other tested materials. COL I transcripts were increased in IRM (P < 0.01), D, C&B and MTA (P < 0.001) when compared with the control. CONCLUSION: Mineral trioxide aggregate provided a more favorable environment for PDL cell adhesion and growth.

Long-term radiologic pulp evaluation after partial pulpotomy in young permanent molars.

OBJECTIVE: Radiographic appearance of pulp reactions to partial pulpotomy in young permanent molars with deep caries may determine the efficiency of the procedure. The objective of this study was to determine the value of this procedure by analyzing the pulpal and periapical appearance of permanent molars after long-term follow-up periods. METHOD AND MATERIALS: Based on predetermined radiologic criteria, periapical radiographs of 49 young permanent molars of 31 females and 13 males, aged 6.9 to 17.7 years (mean, 11.4 years) treated with partial pulpotomy were evaluated and compared to their antimeres. Follow-up time ranged from 7 to 154 months (mean, 49 months). RESULTS: Based on clinical and radiographic findings, the success rate was considered 93.9% (46 of 49 teeth). Three teeth had chronic pulpitis with periapical exacerbation. In 14 (30.4%) of the 46 teeth, normal radiographic pulp appearance was found, and in 2 (4.3%), pulpal calcifications were similar to their antimere tooth. Dentinal bridges were observed underneath the partial pulpotomy site in 27 molars (58.7%), while radiopacities in the pulpotomized pulp horns of 5 teeth (10.9%) suggested development of obstructive calcifications. Increased calcifications of the pulp were seen in 13 (28.3%) molars, in comparison with their antimeres. Six of the 46 molars with immature root development completed full apexogenesis. No periapical pathoses, total pulp obliteration, or resorption were observed. CONCLUSION: The long-term radiologic interpretation of the pulp after partial pulpotomy in young permanent molars supports the clinical impression that it is a warranted treatment in well-chosen cases.

Early response of mechanically exposed dental pulps of swine to antibacterial-hemostatic agents or diode laser irradiation.

OBJECTIVES: The purpose of this study was to compare the effectiveness of an antibacterial and hemostatic agent to diode laser irradiation in the healing of mechanically exposed porcine pulps. MATERIALS AND METHOD: The experiment required three adult swine (Sus scrofa domestica, Yorkshire) with 36 teeth prepared with occlusal penetrations into the pulpal tissues. The preparations were performed under general anesthesia and the pulps were exposed using high speed instrumentation with rubber dam isolation and a disinfected field. Following instrumentation the coronal pulpal tissue was amputated and immediately treated with ferric sulfate and chlorhexidine semi-gel (12), diluted Buckley' formocresol solution (12) for 5 minutes or laser irradiation with a diode laser (12). After treatment, hemostasis was obtained and a ZOE base applied to the treated pulps (36). The pulpal bases were all covered with a RMGI (Fuji II LC). The tissue samples were collected at 4 weeks (28 days). Following fixation, the samples were de-mineralized, sectioned, stained and histologically graded with a scale of 0-4. RESULTS: The treatment groups were statistically different with the Laser Treated Group demonstrating the least inflammation. CONCLUSION: Pulpotomy treatment with the KaVo Gentle Ray Diode Laser demonstrated significantly less inflammation than the other two pulpal therapy modalities. The ferric sulfate and chlorhexidine mixture demonstrated the greatest inflammation as histologically graded. Also, the histological sections of pulpotomized swine teeth treated with the ferric sulfate and chlorhexidine mixture presented with black pigmented areas in the pulp and surrounding tissue. The formocresol group (clinical standard) and the diode laser group did not present with the black precipitate.

Super-EBA and IRM as root-end fillings in periapical surgery with ultrasonic preparation: a prospective randomized clinical study of 206 consecutive teeth.

OBJECTIVE: This study evaluated the treatment outcome after periapical surgery with the use of 2 different retrograde root-filling materials and the influence of 3 pre- and perioperative variables on the periapical healing. STUDY DESIGN: Two hundred six teeth in 164 patients were randomly allocated to receive either IRM or Super-EBA as a retrograde root-end seal. The teeth were reviewed 12 months after surgery. The influence of lesion size, lesion type, and orthograde root filling quality on healing was analyzed. RESULTS: One hundred ninety-four teeth in 153 patients were reviewed. Radiologic evaluation and clinical examination revealed 91% success rate for the IRM group and 82% for the Super-EBA group. There was no statistical significance in the healing outcome between the 2 groups (Fisher exact test). The analyzed pre- and perioperative variables had no significant influence on the treatment outcome (Z test). CONCLUSIONS: Both retrograde materials tested in this study can serve as a root-end seal in periapical infected teeth, according to the results of the healing outcome after 12 months' follow-up.

Persistence of dead-cell bacterial DNA in ex vivo root canals and influence of nucleases on DNA decay in vitro.

OBJECTIVE: The fate of DNA from bacteria that do not survive in the root canal is uncertain, yet DNA longevity may confound recovery of authentic etiologic participants in the disease process. This study assessed the recovery of PCR-detectable DNA in ex vivo human root canals and some environmental factors on the decay of microbial DNA. STUDY DESIGN: Heat-killed Enterococcus faecalis cells were inoculated into instrumented human root canals ex vivo, and samples were taken at intervals over 2 years and analyzed by polymerase chain reaction. In an in vitro assay, heat-killed E. faecalis cells and extracted E. faecalis DNA were inoculated into various media, DNase, and culture of a DNase-producing species, Prevotella intermedia. Recovery of DNA was assessed by gel electrophoresis. RESULTS: In ex vivo human teeth, amplifiable DNA was recovered after 1 and 2 years (in 14/15 and 21/25 teeth, respectively). In vitro experiments showed that extracted DNA incubated in different media (water, 10%-50% sera, and DNase) progressively decomposed to levels below the detection limit. In corresponding assays, cell-bound DNA was more resistant to decay. CONCLUSION: Amplifiable DNA is preserved after cell death, but the critical determinant is the form of DNA. Free DNA undergoes spontaneous and enzymatic decomposition, whereas cell-bound E. faecalis DNA persists for long periods.