MATERIALS AND METHODS: Sound extracted human molars were randomly divided into: manufacturer's instructions (MI), manual blend 2 mm (MB2), and manual blend 4 mm (MB4). Occlusal enamel was removed and flattened, dentin surfaces were bonded by Prime & Bond universal (Dentsply and Optibond FL, Kerr). For the MI group, adhesives were applied following the manufacturer's instructions then light-cured. For MB groups, SDR flow+ bulk-fill flowable composite resin was applied in 2- or 4-mm increment then manually rubbed by a micro brush for 15 s with uncured dentine bonding agents and the mixture was light-cured. Composite buildup was fabricated incrementally using Ceram.X One, Dentsply nanohybrid composite resin restorative material. After 24-h water storage, the teeth were sectioned to obtain beams of about 0.8 mm2 for 24-h and thermocycled micro-tensile bond strength at 0.5 mm/min crosshead speed. Degree of conversion was evaluated with micro-Raman spectroscopy. Contraction gaps at 24 h after polymerization were evaluated and atomic force microscopy (AFM) nano-indentation processes were undertaken for measuring the hardness across the interface. Depth of resin penetration was studied using a scanning electron microscope (SEM). Bond strength data was expressed using two-way ANOVA followed by Tukey's test. Nanoindentation hardness was separately analyzed using one-way ANOVA.

RESULTS: Factors "storage F = 6.3" and "application F = 30.11" significantly affected the bond strength to dentine. For Optibond FL, no significant difference in nanoleakage was found in MI/MB4 groups between baseline and aged specimens; significant difference in nanoleakage score was observed in MB2 groups. Confocal microscopy analysis showed MB2 Optibond FL and Prime & Bond universal specimens diffusing within the dentine. Contraction gap was significantly reduced in MB2 specimens in both adhesive systems. Degree of conversion (DC) of the MB2 specimens were numerically more compared to MS1 in both adhesive systems.

Objectives: The aim of this study is to evaluate the efficacy of dentin bonding agent (DBA) in preventing coronal discoloration caused by four different root canal sealers- MTA Fillapex, Sealapex, Zical and Z. O. B seal at different time intervals by measuring chromatic alterations using digital images analysis method.

Methodology: Ninety mandibular premolars were collected and sectioned at 1 mm below the cementoenamel junction. Standard access cavity preparations of dimensions (depth-3 mm, width-0.8 mm, and length-3 mm) were prepared with a No. 245 bur through the cervical access. Following the standard irrigation protocol, specimens were then randomly divided into nine groups (four groups without DBA [1-4] +4 groups with DBA [5-8] +1 negative control [9]). In Groups 1-4, four different root canal sealers (MTA Fillapex, Sealapex, Zical, and Z.O.B seal) were applied to the walls of the pulp chamber. For Groups 5-8, the samples were etched with 37% phosphoric acid and DBA application was done before the respective root canal sealer application. The cervical access in all specimens was sealed using glass ionomer cement. Digital photographs were taken under standard lighting and environmental conditions at different time intervals: preprocedural, postprocedural, and after 1, 2, 3, and 4 months. These images were analyzed using Adobe Photoshop CS6 from which laboratory values and subsequently Delta E values were obtained.

Results: Statistical analysis performed using repeated measures ANOVA and post hoc Tukey's tests show that the groups with DBA application had significantly lower mean Delta E values (P < 0.05) compared to the groups without DBA application.

METHODS: The design was a parallel double blind, randomized clinical trial. Mature teeth with caries radiographically extending ≥ 2/3 of dentine and without spontaneous pulpitis were included. Teeth were allocated to either selective (SCR) or total caries removal (TCR) using block randomization technique. In the SCR group, caries removal to firm dentine was followed by placement of Biodentine and composite restoration. In TCR group caries removal was to hard dentine; with immediate management by vital pulp therapy (VPT) using Biodentine in case of pulp exposure. Preoperative pain levels were recorded. Teeth were followed up after 6 and 12 months. Data were analyzed using Chi square test and regression analysis.

RESULTS: 124 teeth with a diagnosis of reversible pulpitis were treated (63 in SCR, 61 in TCR). 17/ 61 teeth (28%) in the TCR had pulp exposure, managed by VPT and were successful at recall. Pulp survival was significantly higher in TCR compared to SCR at 6 months (100 % vs 93.65%, p =0.04 respectively) and at 12 months (98.4% vs 82.5, P= 0.003 respectively). Multivariate analysis revealed the type of procedure (SCR vs TCR) and the preoperative pain levels (above or below 5/10) as significant prognostic factors. The odds of failure increased significantly for teeth treated with SCR (OR 27.6, 3.6-212.4, p=0.001) and if preoperative pain levels were ≥5/10 (OR 0.2, 0.04-0.8, P=0.024).

CONCLUSION: Selective caries removal for deep carious lesions in mature teeth failed to reveal overt pulp exposures in more than one quarter of cases and led to significantly lower pulp survival over one year, when compared with complete caries removal and immediate VPT.

CLINICAL SIGNIFICANCE: In deep carious lesions of mature permeant teeth with revrsible pulpitis, total caries removal to hard dentine is recommended for a predictable pulp survival.

PURPOSE: The purpose of this laboratory and finite element analysis study was to investigate the effects on the formation of a hybrid layer of an experimental silane coupling agent containing primer solutions composed of different percentages of hydroxyethyl methacrylate.

MATERIAL AND METHODS: A total of 125 sound human premolars were restored in vitro. Simple class I cavities were formed on each tooth, followed by the application of different compositions of experimental silane primers (0%, 5%, 25%, and 50% of hydroxyethyl methacrylate), bonding agents, and dental composite resins. Bond strength tests and scanning electron microscopy analyses were performed. The laboratory experimental results were validated with finite element analysis to determine the pattern of stress distribution. Simulations were conducted by placing the restorative composite resin in a premolar tooth by imitating simple class I cavities. The laboratory and finite element analysis data were significantly different from each other, as determined by 1-way ANOVA. A post hoc analysis was conducted on the bond strength data to further clarify the effects of silane primers.

RESULTS: The strongest bond of hybrid layer (16.96 MPa) was found in the primer with 25% hydroxyethyl methacrylate, suggesting a barely visible hybrid layer barrier. The control specimens without the application of the primer and the primer specimens with no hydroxyethyl methacrylate exhibited the lowest strength values (8.30 MPa and 11.78 MPa) with intermittent and low visibility of the hybrid layer. These results were supported by finite element analysis that suggested an evenly distributed stress on the model with 25% hydroxyethyl methacrylate.

MATERIALS AND METHODS: Thirty single-rooted mandibular premolars were standardized and prepared using ProTaper rotary files. The specimens were divided into a control group and two experimental groups receiving Diapex and Odontopaste medicament, either filled with iRoot SP or OrthoMTA, for 1 week. Each root was sectioned transversally, and the push-out bond strength and failure modes were evaluated. The data were analyzed using Kruskal Wallis and Mann-Whitney U post hoc test.

RESULTS: There was no significant difference between the bond strength of iRoot SP and OrthoMTA without medicaments and with the prior placement of Diapex (p value > 0.05). However, iRoot SP showed significantly higher bond strength with the prior placement of Odontopaste (p value < 0.05). Also, there was no association between bond strength of OrthoMTA with or without intracanal medicament (p value > 0.05) and between failure mode and root filling materials (p value > 0.05). The prominent failure mode for all groups was cohesive.

CONCLUSION: Prior application of Diapex has no effect on the bond strength of iRoot SP and OrthoMTA. However, Odontopaste improved the bond strength of iRoot SP.

Settings and Design: Endodontic treatment aims at disinfection and then obturation of root canal system in to prevent re-infection. Root canal irrigants play a pivotal role in the disinfection process. One of the important properties of an irrigant is the removal of complete smear layer and debris. Smear layer has the potential to protect bacteria within the dentinal tubules; therefore removal may be prudent. Smear layer removal increases the bond strength of resin sealers which results in better apical seal.

Materials and Methods: Forty extracted single-rooted, primary teeth were allocated randomly into four groups of ten each: Group 1 - NaOCl, Group 2 - Nutmeg, Group 3 - Myrobolan, and Group 4 - Tulsi. Samples were stored in sterile saline (0.9% NaCl) and then decoronated at the level of the cementoenamel junction. Working length was determined followed by appropriate irrigation. The roots were split into two halves with a chisel and were stored in 2.5% glutaraldehyde solution for 24 h. After fixation, the samples were dehydrated in ethanol series (70, 90, and 95 and twice at 100%). Each specimen was mounted on Al stub and sputter coated with a 20 nm layer of gold. Samples were then examined using a SEM quantum 60 at magnification of ×2000.

Results: Tulsi demonstrated the most statistically significant results followed by myrobolan and nutmeg extract. All herbal extracts were found to be significantly effective than 2.5% NaOCl.