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The purpose of this study was to compare fluid flow rates across dentin surfaces treated with four conditioners. The effect of conditioning on the micro-shear bond strengths of glass ionomer cement (Fuji IX GP) and resin-based adhesives (Single Bond 2 or Clearfil SE Bond) were also investigated. Under a simulated pressure of 1.3 kPa, two dentin conditioners, phosphoric acid, and a self-etching primer were applied to the dentin surfaces. Dentinal fluid flows at baseline and after conditioning were recorded for 15 min each. The conditioned surfaces were examined using a scanning electron microscope. The micro-shear bond strengths of the glass ionomer cement and of the resin-based adhesives bonded to conditioned dentin surfaces were evaluated while simulated intrapulpal pressure was maintained at 0 or 1.3 kPa. Only the dentin surface etched with phosphoric acid showed a significant increase in permeability. Micro-shear bond strengths of Fuji IX GP were not affected by conditioning the dentin surfaces or by bonding at different intrapulpal pressures (0 or 1.3 kPa). The effects on bond strengths of resin-based adhesives depended on the system used. The simulated positive intrapulpal pressure during bonding significantly affected the adherence of Single Bond 2, whereas Clearfil SE Bond was unaffected.

The purpose of this work was to investigate fluid flow after restoration using four restorative procedures. Micro-gap, internal dye leakage, and micropermeability of bonded interfaces were also investigated. Each tooth was mounted, connected to a fluid flow-measuring device, and an occlusal cavity was prepared. Fluid flow after cavity preparation was recorded as the baseline measurement, and the cavity was restored using one of four restorative procedures: bonding with total-etch (Single Bond 2) or self-etch (Clearfil SE Bond) adhesives without lining; or lining with resin-modified glass-ionomer cement (GIC) (Fuji Lining LC) or conventional GIC (Fuji IX) and then bonding with the total-etch adhesive. Fluid flow was recorded after restoration and at specific time-points up to 6 months thereafter and recorded as a percentage. Micro-gap formation was analyzed using resin replicas and scanning electron microscopy. Internal leakage of 2% methylene blue dye was observed under a light microscope. In micro-permeability testing, fluorescent-dye penetration was investigated using confocal laser microscopy. None of the restorative procedures provided a perfectly sealed restoration. Glass-ionomer lining did not reduce fluid flow after restoration, and micro-gaps were frequently detected. The self-etch adhesive failed to provide a better seal than the total-etch adhesive, and even initial gap formation was rarely observed for the former. Penetration of methylene blue and fluorescent dyes was detected in most restorations.

This study investigated the ability of a glassionomer cement (GIC) lining to reduce postoperative sensitivity in occlusal cavities restored with resin composite. In addition, the effects of a total-etch and self-etch adhesive on postoperative sensitivity were also compared. Patients who had moderate to deep occlusal caries of at least one molar were recruited. Overall, 103 restorations were placed in 70 participants, with an average age of 22.8 ± 3.8 years. Preoperatively, each tooth was evaluated for cold-stimulated tooth sensitivity using a visual analog scale. If present, tooth sensitivity induced by cold/hot drinks or occlusal function was also noted. Caries was stained with a caries detector dye, then removed using slow-speed burs and hand excavators. The cavity was restored with one of four randomly allocated restorative procedures: 1) bonded with a two-step, total-etch adhesive (Single Bond 2); 2) lined with a resin-modified GIC liner (Fuji Lining LC), then bonded with total-etch adhesive; 3) bonded with a two-step, self-etch adhesive (Clearfil SE Bond) and 4) lined Clinical RelevanceGlass-ionomer lining showed no benefit in reducing postoperative sensitivity associated with occlusal resin composite restorations. The use of self-etching adhesive demonstrated postoperative sensitivity similar to that of total-etching adhesive. with the GIC liner, then bonded with self-etch adhesive. The cavities were incrementally filled with a nanofilled hybrid resin composite. At recall, postoperative sensitivity was evaluated at one week and one month. Overall, postoperative sensitivity in daily function was rare. No significant difference in postoperative sensitivity, either in daily function or in response to a cold stimulus, was observed between the restorative procedures with or without the GIC liner, regardless of the adhesive used (p>0.05). In addition, no difference in postoperative sensitivity was noted between use of the self-etch and total-etch adhesive.

ObjectivesTo evaluate sealing ability of root canals obturated with bioceramic-impregnated gutta percha cone (BCC) or gutta percha (GP), with bioceramic sealer (BCS) or AH Plus (AH; Dentsply-Maillefer), in roundly-prepared canals using matched single-cone technique, based on bacterial leakage test, and to analyze obturation quality using micro-computed tomography (CT) analysis.Materials and MethodsNinety-two distobuccal roots of maxillary molars were prepared using nickel-titanium files to apical size 40/0.06. The roots were divided into 4 groups (n = 20) that were obturated with a master cone and sealer: GP/AH, BCC/AH, GP/BCS, and BCC/BCS. Bacterial leakage model using Enterococcus faecalis was used to evaluate sealing ability for 60-day period. Obturated samples from each group (n = 4) were analyzed using micro-CT.ResultsAll groups showed bacterial leakage at 20%–45% of samples with mean leakage times of 42–52 days. There were no significant differences in bacterial leakage among the groups. Micro-CT showed minimal gaps and voids in all groups at less than 1%.ConclusionsIn roundly-prepared canals, the single cone obturation with BCC/BCS was comparable to GP/AH for bacterial leakage at 60 days.

Bio-MA, a calcium chloride accerelator-containing calcium-silicate cement, as a pulp capping material was evaluated on mechanically exposed rat molar pulp. Sixty maxillary first molars from Wistar rats were mechanically exposed and assigned to two capping materials: Bio-MA or white mineral trioxide aggregate (WMTA), and three periods: 1, 7, or 30 days. Nine molars were exposed and covered with polytetrafluoroethylene tape, as positive controls. From histological examination, inflammatory cell infiltration and reparative dentin formation were evaluated using grading scores. No significant difference in pulpal responses between the two materials was observed at any period (p>0.05). At 1 day, all experimental groups showed localized mild inflammation. At 7 days, dentin bridge was partially observed at exposure sites with few inflammatory cells. At 30 days, pulp appeared normal with complete tubular dentin bridges. Bio-MA with accerelator was biocompatible similar to WMTA and could be used as a pulp-capping material.

Background/purpose Variations in root and root canal morphology of mandibular premolars of Thais has not been reported, and understanding these variations enhances endodontic success. The purpose was to investigate prevalence and morphology of multiple roots, root canals and C-shaped canals in mandibular premolars in a Thai population from cone-bean computed tomography (CBCT) images. Materials and methods A total of 349 first mandibular premolars and 416 second premolars from CBCT images with 0.125-mm voxel size and 60 × 60 mm field of view were evaluated. Number of roots, root canals, and C-shaped canals were recorded and statistically analyzed using chi-square test. Root canal configurations were defined according to the Vertucci's classification. Levels and distances of separated multiple canals were reported. Results Multiple roots in mandibular first premolars were found at 5.73% while none of second premolars had. Multiple root canals were found in the first premolars at 19.48% and the second premolars at 3.85%. C-shaped canals (C1/C2) were found in the first premolars at 3.72% and the second premolars at 0.48%. All parameters in the first premolars were significantly higher than in the second premolars (p < 0.01). The majority of multiple root canals were defined as Vertucci's type V (1–2 canals). Multiple root canals were frequently separated at the middle level of roots about 6.5–7.0 mm from the cementoenamel junction. Conclusion Prevalence of multiple roots/root canals and C-shaped canals in mandibular first premolars were significantly higher than in mandibular second premolars. Level of separation in multiple root canals was frequently at the mid-root level.

This systematic review aims to summarize the current clinical studies that investigated survival rates against fracture of endodontically treated posterior teeth restored with crowns or resin composite restorations. Literature search were performed using keywords. Publications from 1980 to 2016 were searched in PubMed, ScienceDirect, Web of Science, MEDLINE, and SCOPUS. Included studies were selected based on inclusion and exclusion criteria. Three clinical studies were included: 1 randomized controlled trial and 1 prospective and 1 retrospective cohort studies. Pooled survival rates ranged from 94%–100% and 91.9%–100% for crowns and resin composite, respectively. The majority of teeth had no more than 3 surface loss of tooth structure. The studies included were heterogeneous, and were not appropriate for further meta-analysis. Current evidence suggested that the survival rates against the fracture of endodontically treated posterior teeth restored with crowns or resin composites were not significantly different in the teeth with minimum to moderate loss of tooth structure.