Impact of the quality of coronal restoration versus the quality of root canal fillings on success of root canal treatment: a systematic review and meta-analysis.

INTRODUCTION: Thorough cleaning and shaping of root canals are essential for periapical healing. Restoration of endodontically treated teeth is also required for them to function and prevent coronal leakage. This study compared the impact of the quality of root canal treatment versus the quality of coronal restoration in treatment outcomes. METHODS: Literature search was conducted using the search terms "coronal restoration," "root canal," "periapical status," and "quality." Articles that evaluated the effect of the quality of root filling and coronal restoration or both on the success of root canal treatment were selected. Nine articles were identified and were reviewed by 3 investigators. Data were collected based on predetermined criteria. Percentages of teeth without apical periodontitis were recorded for each category: adequate root canal treatment (AE), inadequate root canal treatment (IE), adequate restoration (AR), and inadequate restoration (IR). Data were analyzed using meta-analysis for odds ratios (ORs). RESULTS: After adjusting for significant covariates to reduce heterogeneity, the results were combined to obtain pooled estimates of the common OR for the comparison of AR/AE versus AR/IE (OR = 2.734; 95% confidence interval [CI], 2.61-2.88; P < .001) and AR/AE versus IR/AE (OR = 2.808; 95% CI, 2.64-2.97; P < .001). CONCLUSIONS: On the basis of the current best available evidence, the odds for healing of apical periodontitis increase with both adequate root canal treatment and adequate restorative treatment. Although poorer clinical outcomes may be expected with adequate root filling-inadequate coronal restoration and inadequate root filling-adequate coronal restoration, there is no significant difference in the odds of healing between these 2 combinations.

Setting properties and cytotoxicity evaluation of a premixed bioceramic root canal sealer.

INTRODUCTION: This study investigated the setting time and micohardness of a premixed calcium phosphate silicate-based sealer (EndoSequence BC Sealer; Brasseler USA, Savannah, GA) in the presence of different moisture contents (0-9 wt%). The moisture content that produced the most optimal setting properties was used to prepare set EndoSequence BC Sealer for cytotoxicity comparison with an epoxy resin-based sealer (AH Plus; Dentsply Caulk, Milford, DE). METHODS: Standardized disks were created with BC Sealer, AH Plus, Pulp Canal Sealer EWT (positive control) (SybronEndo, Orange CA), and Teflon (Small Parts Inc., Miami Lakes, FL; negative control). Disks were placed in Transwell Inserts, providing indirect contact with MC3T3-E1 cells. Succinate dehydrogenase activity of the cells was evaluated over a 6-week period using MTT ((3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. Cytotoxicity profiles of BC Sealer and AH Plus were fitted with polynomial regression models. The time for 50% of the cells to survive (T(0.5)) was analyzed using the Wald statistic with a two-tailed significance level of 0.05. RESULTS: BC Sealer required at least 168 hours to reach the final setting using the Gilmore needle method, and its microhardeness significantly declined when water was included in the sealer (P = .004). All set sealers exhibited severe cytotoxicity at 24 hours. The cytotoxicity of AH Plus gradually decreased and became noncytotoxic, whereas BC Sealer remained moderately cytotoxic over the 6-week period. A significant difference (P < .001) was detected between T(0.5) of BC Sealer (5.10 weeks; 95% confidence interval [CI], 4.69-5.42, standard error [SE] = 0.09) and T(0.5) of AH Plus (0.86 weeks; 95% CI, 0.68-1.05; SE = 0.18). CONCLUSIONS: Further studies are required to evaluate the correlation between the length of setting time of BC Sealer and its degree of cytotoxicity.