Survival and Factors Associated with Failure of Pulpectomies Performed in Primary Teeth by Dental Students

Abstract Although endodontic treatment is widely recommended for compromised dental pulp, there is no information regarding the factors associated with failures in primary teeth. The aim of this study was to evaluate the survival and factors associated with failure of pulpectomies performed in primary teeth by dental students. The sample comprised patients treated at a University Dental Service and required endodontic treatment in primary teeth. The study investigated treatment-related variables and patient factors potentially associated with treatment failure. Pulpectomy survival was analyzed by Kaplan-Meier estimator followed by log-rank test (p<0.05). The analysis included 81 pulpectomies performed in 62 children (5.6±1.5 years). The survival reached 62.9% up to 12 months follow-up. Most failures occurred in the first 3 months (p<0.001). Teeth with carious lesions at the start of treatment presented more failures than those with restorations or history of trauma (p=0.002). The survival of endodontically treated teeth restored with composite was higher than the ones filled with GIC (p=0.006). Pulpectomy performed in two or more sessions resulted in more failures (p=0.028). Patients presenting gingivitis had more failures in the endodontic treatment (p=0.022). The failures of root canal treatment in primary teeth were more prone to occur in a short time and when the treatment was performed in teeth presenting carious lesions. The use of composite instead of GIC increased the survival of pulpectomies. Repeated sessions for endodontic treatment and lack of oral hygiene habits had a negative effect on the results

Bond strength of resin-resin interfaces contaminated with saliva and submitted to different surface treatments

The purpose of this study was to investigate the effect of different surface treatments on shear bond strength of saliva-contaminated resin-resin interfaces. Flat resin surfaces were fabricated. In the control group, no contamination or surface treatment was performed. The resin surfaces of the experimental groups were contaminated with saliva and air-dried, and then submitted to: (G1) rinsing with water and drying; (G2) application of an adhesive system; (G3) rinsing and drying, abrasion with finishing disks, etching and application of adhesive system; (G4) rinsing and drying, etching, application of silane and adhesive system. Resin cylinders were placed over the treated surfaces. The specimens were stored in water or ethanol. Shear bond strength tests were performed and the mode of failure was evaluated. Data were submitted to two-way ANOVA and Dunnett T3 test. Contamination of resin-resin interfaces with saliva significantly reduced shear strength, especially after prolonged storage (p<0.05). Similar values to the original bond strength were obtained after abrasion and application of adhesive (G3) or etching and application of silane and adhesive (G4). If contamination occurs, a surface treatment is required to guarantee an adequate interaction between the resin increments