Evaluation of the penetration of intracoronal bleaching agents into the cervical region using different intraorifice barriers

A Randomized Controlled Clinical Trial of the Performance of Three Bioactive Endodontic Cements in Primary Molar Teeth Diagnosed with Reversible Pulpitis: 1-Year Follow-Up Study

OBJECTIVES

The objective of this clinical trial was to evaluate and compare the clinical and radiographic successes of three bioactive endodontic cements (BEC) including novel portland cement-based material releasing fluoride, resin-modified silicate glass cement, and pure tricalcium silicate-based cement-in the treatment of primary molars diagnosed with reversible pulpitis via indirect pulp capping.

METHODS

Eighty-six (86) participants with previously untreated first and second primary molars were included in this study. The teeth were randomly allocated into three groups: pure tricalcium silicate-based cement, resin-modified silicate glass cement, and novel portland cement-based material releasing fluoride. Cavities were capped with the assigned cement after caries excavation using standard protocols. The teeth that underwent treatment were restored using glass ionomer cement and composite resin. Clinical and radiographic evaluations were performed at 1, 6, and 12 months. The data were analyzed using Pearson chi-square, Kruskal-Wallis H and Z test (P = 0.05).

RESULTS

The success rate was 88% (n=25) in the pure tricalcium silicate-based cement group, 88.5% (n=26) in the resin-modified silicate glass cement group, and 100% (n=25) in the novel portland cement-based material releasing fluoride group. The differences at the 1st, 6th, and 12th month follow-up visits were not statistically significant among the groups (P>0.05). No difference was found between the integrity of the resin composite restorations overlying pure tricalcium silicate-based cement, resin-modified silicate glass cement, and novel portland cement-based material releasing fluoride according to the USPHS criteria.

CONCLUSIONS

Novel portland cement-based material releasing fluoride can be considered an alternative for preserving the tooth, as it showed a high success rate in treating primary molars diagnosed with reversible pulpitis via indirect pulp capping.

CLINICAL SIGNIFICANCE

Novel Portland cement-based material releasing fluoride could be beneficial in the treatment of primary molars diagnosed with reversible pulpitis via indirect pulp capping.

Multidisciplinary conservative management of a severely discolored nonvital tooth

This clinical report describes a multidisciplinary protocol for the management of a severely discolored nonvital maxillary anterior tooth based on minimally invasive treatment with in-office and home bleaching combined with restoration with composite resin.

Evaluating the Effect of Different Intra-Orifice Barriers and Various Bleaching Agents on the Fracture Resistance of Teeth After the Walking Bleach Procedure: An In Vitro Study

Objective This study aimed to evaluate the effect of three different commercially available intra-orifice barriers and bleaching agents on root canal-treated teeth. Materials and methods Forty-five freshly extracted single-rooted incisors, canine, and premolars were collected and stored in 10% formalin. Root canal procedures were performed on the extracted teeth and these were classified into three groups and three subgroups (n=5). Group 1: resin-modified glass ionomer cement (RMGIC); placed at the level of cemento-enamel junction (CEJ) and cured for 20 seconds. Group 2: Biodentin^TM (Septodont Ltd., Saint Maur des Fausse´s, France); powder and liquid were mixed according to the manufacturer's instructions and placed at the level of CEJ, and waited for 15 minutes to set. Group 3: bulk-fill composite; placed at the level of CEJ. Group A was treated with 35% carbamide peroxide (Ultradent Opalescence 35% PF regular). Group B was bleached with 35% hydrogen peroxide (Pola Office). Group C, which was the control group, was treated with distilled water. The bleaching procedure was repeated once every seven days for a period of three weeks. After bleaching, every sample was sectioned 2 mm above the level of CEJ to remove the crown. Auniversal testing machine (UTM) was used for the evaluation of the fracture resistance of teeth. Data were analyzed for significance by using analysis of variance (ANOVA) and further pair-wise comparison was performed by pos-hoc analysis. The level of significance was set at p<0.05 Results There was a significant difference between the fracture resistance of the three materials when bleached using distilled water (p<0.05). The fracture resistance of Group 3 was significantly greater than that of Group 2 and Group 1 (p<0.05). The difference in the fracture resistance between Group 1 and Group 2 was nonsignificant (p>0.05). Conclusion Walking bleach performed via bleaching agents 35% carbamide peroxide and 35% hydrogen peroxide leads to a reduction in the fracture resistance of endodontically treated teeth; 35% hydrogen peroxide causes more fracture resistance reduction than carbamide peroxide of the same concentration. The presence of intra-orifice barriers leads to greater fracture resistance and reinforcement of endodontically treated teeth that undergo the walking bleach procedure. Bulk-fill composite can be used as an intra-orifice barrier with good fracture resistance.

Effect of quercetin pretreatment on the immediate and aged bond strength of bleached dentin

This in vitro study aimed to investigate the effect of quercetin pretreatment on the bond strength of bleached dentin. Human dentin blocks (2 × 2 × 1 mm) were prepared and randomly divided into 5 groups (n = 16): deionized water pretreatment + no bleaching treatment (DNB); deionized water pretreatment + bleaching treatment (DYB); 75 μg/mL quercetin pretreatment + bleaching (Q75B); 150 μg/mL quercetin pretreatment + bleaching (Q150B); and 300 μg/mL quercetin pretreatment + bleaching (Q300B). The surfaces of superficial dentin (bonding surfaces) were treated with the respective solutions for 2 min, and then the surfaces opposite to the bonding surfaces (near pulp, bleaching surfaces) were subjected to bleaching treatment with 40% hydrogen peroxide (Ultradent, USA) for two 15-min sessions (groups DYB, Q75B, Q150B, and Q300B). After the bleaching procedure, the bonding surfaces were bonded with resin cements (Panavia V5, Kuraray, Japan). The bonded specimens were then divided into 2 subgroups (n = 8): the aging group (subgroup T), which was subjected to 10,000 thermocycles, and the nonaging group (subgroup N), which was not subjected to thermocycling. The microshear bond strength (μSBS) was obtained using a universal testing machine (AGS-X, Shimadzu, Tokyo, Japan). Additional dentin blocks (5 × 5 × 1 mm) were prepared and treated the same as the groups DYB, Q75B, Q150B, and Q300B (n = 8) to evaluate the color change, defined as groups CC_DYB, CC_Q75B, CC_Q150B, and CC_Q300B, respectively. Color evaluation was performed using a spectrophotometer (Vita Easyshade Advance 4.0, Vident, USA) to obtain a baseline and again at the end of the bleaching treatment. The data were analyzed via two-way analysis of variance (ANOVA) and Tukey's post-hoc test (α = 0.05). For the immediate bond strength, the specimens in the groups Q75B, Q150B, and Q300B showed significantly higher μSBS values than those in the group DYB (all P < 0.05). No significant differences in the μSBS values were found among the groups Q75B, Q150B, Q300B, and DNB, respectively (all P > 0.05). For the aged bond strength, both the groups Q150B and Q300B exhibited significantly higher μSBS values than groups DYB and DNB (all P < 0.05), whereas no significance differences were found between groups Q150B and Q300B (P = 1.00) or between the groups DYB and DNB (P = 1.00). No significant differences were observed in the △E values among all the groups tested (P = 0.80). Therefore, the application of quercetin for 2 min prior to the bleaching procedure preserved the immediate bond strength and improved the aged bond strength of bleached dentin while maintaining the effectiveness of bleaching.