The latest in endodontic research

Dr. Kishor Gulabivala presents the latest literature, keeping you up-to-date with the most relevant research

5-year results comparing mineral trioxide aggregate and adhesive resin composite for root-end sealing in apical surgery
Von Arx T, Hänni S, Jensen SS. Journal of Endodontics (2014) 40(8):1077-81

Abstract
     Aim: Recent meta-analyses of the outcome of apical surgery using modern techniques, including microsurgical principles and high-power magnification, have yielded higher rates of healing. However, the information is mainly based on 1- to 2-year follow-up data. The present prospective study was designed to re-examine a large sample of teeth treated with apical surgery after 5 years.

     Methodology: Patients were recalled 5 years after apical surgery, and treated teeth were classified as healed or not healed based on clinical and radiographic examination. (The latter was performed independently by three observers.) Two different methods of root-end preparation and filling (primary study parameters) were to be compared (mineral trioxide aggregate [MTA] versus adhesive resin composite [COMP]) without randomization.

     Results: A total of 271 patients and teeth from a 1-year follow-up sample of 339 could be re-examined after 5 years (dropout rate = 20.1%). The overall rate of healed cases was 84.5% with a significant difference (P = .0003) when comparing MTA (92.5%) and COMP (76.6%). The evaluation of secondary study parameters yielded no significant difference for healing outcome when comparing subcategories (i.e., sex, age, type of tooth treated, post/screw, type of surgery).

     Conclusion: The results from this prospective non-randomized clinical study with a 5-year follow-up of 271 teeth indicate that MTA exhibited a higher healing rate than COMP in the longitudinal prognosis of root-end sealing.

The effect of photodynamic therapy in root canal disinfection: a systematic review
Chrepa V, Kotsakis GA, Pagonis TC, Hargreaves KM. Journal of Endodontics (2014) 40(7):891-8

Abstract
     Aim: Effective root canal disinfection is a fundamental component of successful root canal treatment. Photodynamic therapy (PDT) has been proposed as a new adjunctive method for additional disinfection of the root canal system with the possibility of improved treatment outcomes. The aim of this systematic review was to investigate the effect of PDT on bacterial load reduction during root canal disinfection.

     Methodology: Two reviewers independently conducted a comprehensive literature search using a combination of medical subject heading terms and keywords to identify studies relevant to the population intervention control outcome question. The selection of articles for inclusion was performed in two phases, based on predetermined eligibility criteria according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Inter-reviewer agreement for each phase was recorded. The effect of PDT on bacterial load reduction during root canal disinfection was evaluated as the primary outcome variable during data extraction.

     Results: The literature search provided 57 titles and abstracts. Three articles met the inclusion criteria and were selected for this systematic review. The reasons for study exclusion in each phase were recorded. Because of the heterogeneity in clinical indications and PDT protocols among the included studies, a meta-analysis could not be performed. All included studies showed a positive effect of PDT in the reduction of microbial load in root canal treatment ranging from 91.3%-100%.

     Conclusion: Limited clinical information is currently available on the use of PDT in root canal disinfection. If supported by future clinical research, PDT may have efficacy for additional root canal disinfection, especially in the presence of multi-drug-resistant bacteria.

Periapical status of non-root-filled teeth with resin composite, amalgam, or full crown restorations: a cross-sectional study of a Swedish adult population
Dawson V, Petersson K, Wolf E, Akerman S. Journal of Endodontics (2014) 40(9):1303-8

Abstract
     Aim: Experimental studies show that dental pulp cells respond unfavorably to contact with resin composite restorative material. Hypothetically, in a random population, the frequency of apical periodontitis should be higher for teeth restored with resin composite than with amalgam. Therefore, the aim was to compare the periapical status of non-root-filled teeth restored with resin composite, amalgam, or laboratory-fabricated crowns in an adult Swedish population.

     Methodology: The subjects comprised 440 individuals from a randomly selected sample of 1,000 adult residents of a Swedish county. The type, material, and quality of the restorations were recorded for all non-root-filled teeth by clinical examination and intraoral clinical photographs. Periapical status was evaluated on panoramic radiographs. The association between periapical status and type, material, and quality of the restorations was analyzed using the chi-square test and logistic regression analysis.

     Results: There was no significant difference in the frequency of apical periodontitis (AP) between teeth restored with resin composite or amalgam (1.3% and 1.1%, respectively). The frequency of AP for teeth restored with laboratory-fabricated crowns was significantly higher (6.3%). Regression analysis showed no association between AP and resin composite restorations but a significant association with laboratory-fabricated crowns.

     Conclusion: The results indicate that the risk of damage to the pulp-dentin complex from exposure to resin composite material and dentin bonding agents shown in experimental studies is not reflected in the clinical setting. However, in the study sample, AP was diagnosed in a significantly higher proportion of teeth restored with laboratory-fabricated crowns.

The critical time lapse between various restoration placements and subsequent endodontic intervention
Kwang S, Aminoshariae A, Harding J, Montagnese TA, Mickel A. Journal of Endodontics (2014) 40(12):1922-6

Abstract
     Aim: The purpose of this study was two-fold: first, to investigate the critical time lapse of endodontic intervention subsequent to various restorations and tooth surfaces, and second, to assess and compare the risk factors associated with the restorations, tooth surfaces, and endodontic treatment.

     Methodology: A comprehensive computerized analysis of all dental school patients at the Case Western Reserve University School of Dental Medicine who received restorations from 2008-2013 was obtained. Inclusion and exclusion criteria were applied. The sample size was limited to teeth with endodontic treatment completed by the endodontic postgraduate dental clinic. Data collected included restoration type, restored tooth surfaces, tooth type, and the dates of restoration and subsequent endodontic treatment. A two-sample paired t-test (95% confidence interval, P < .05) and pair-wise comparison with Bonferroni corrections were implemented.

     Results: The mean time between restoration placement and resultant endodontic intervention was 270 days, with a mean difference of 247-294 days (P <.0001). Further analysis revealed composite resin was 1.91 times more likely than amalgam and 5.69 times more likely than crowns to cause endodontic intervention. Teeth with two or more restorative surfaces required endodontic intervention (P < .001).

     Conclusion: Of the patients who required endodontic treatment after restoration placement, the critical time lapse was 9 months. Composite restorations and teeth with two or more restorative surfaces were significantly associated with endodontic treatment. From the results of the current study, we recommended that all dental practitioners should perform a thorough endodontic evaluation and diagnosis before, during, and after all restorative procedures.

Histological evaluation to study the effects of dental amalgam and composite restoration on human dental pulp: an in vivo study
Chandwani ND, Pawar MG, Tupkari JV, Yuwanati M. Medical Principles & Practice (2014) 23(1):40-4

Abstract
     Aim: To study and compare the effects of dental amalgam and composite restorations on human dental pulp.

     Methodology: One hundred sound premolars scheduled for orthodontic extraction were divided equally into two groups: group A, teeth restored with silver amalgam, and group B, teeth restored with composite resin. Each group was equally subdivided into two subgroups (extracted after 24 hours [A-1 and B-1] or 7 days [A-2 and B-2]), and the histological changes in the pulp related to the two different materials at the two different intervals were studied.

     Results: It was found that after 24 hours, the inflammatory response of the pulp in teeth restored with amalgam and composite was similar (p = 1.00). However, after 7 days, the severity of the inflammatory response of the pulp in teeth restored with amalgam was less compared to that in teeth restored with composite (p = 0.045).

     Conclusion: This study confirmed that amalgam continues to be the mechanically as well as biologically more competent restorative material. Composite could be a promising restorative material to satisfy esthetic needs for a considerable period of time. However, its biological acceptance is still in doubt.

Treatment outcome of the teeth with cemental tears
Lin HJ, Chang MC, Chang SH, Wu CT, Tsai YL, Huang CC, Chang SF, Cheng YW, Chan CP, Jeng JH. Journal of Endodontics (2014) 40(9):1315-20

Abstract
Aim: A cemental tear is a special type of surface root fracture noted in combination with periodontal and/or periapical bony destruction. It was hypothesized that clinical characteristics and treatment techniques may affect the prognosis of teeth with cemental tears.

Methodology: Treatment outcome for the teeth with a cemental tear was assessed in a multicenter cemental tear study project. Of the 71 teeth with cemental tears, 38 teeth (53.5%) were extracted. The remaining 33 teeth (46.5%) were examined for a treatment outcome of healed, questionable, or failed.

Results: Outcome assessment found that 51.5% (17/33), 42.4% (14/33), and 6.1% (2/33) of teeth were classified as healed, questionable, and failed, respectively. Additive bivariate analysis indicated a significant difference between treatment outcome and the length (P = .01) and apicocoronal location (P = .02) of the separated root fragments. Logistic regression analysis found that treatment technique and apicocoronal location of cemental tears may affect the treatment outcome. The percentage of healed cemental tear cases located in the apical, middle, and cervical third of roots was 11.1%, 66.7%, and 60.0%, respectively. By surgical management, 57.7% of cemental tears were healed, whereas only 28.6% cases were healed after nonsurgical treatment.

Conclusions: Most teeth with cemental tears can be retained to function by nonsurgical and surgical periodontal and endodontic treatment. Clinical diagnosis and treatment of cemental tears should also consider the apicocoronal location and the type of treatment technique to improve outcomes.