Periodontal Disease: Its Impact on Restorative Dentistry

The effect of diabetes on the tensile bond strength of a restorative dental composite to dentin

This study was performed to evaluate the effect of diabetes mellitus (DM) on the tensile bond strength (TBS) of dental composite resin bonding to enamel and dentin of extracted human teeth. Thirty caries-free human premolar teeth (10 from type 1 DM (D1), 10 from type 2 DM (D2), and 10 from non-diabetic individuals (control)) were wet ground and polished to obtain flat surfaces of dentin (n = 10). 37% phosphoric acid was used to etch dentin specimens for 15 s. After the application of the adhesive system, the composite resins were applied and cured for 20 s. Then, specimens were subjected to TBS testing by Universal Testing Machine (1 mm/min). One specimen from each group was prepared and observed under a scanning electron microscope (SEM) and a dot map was generated. Data were analyzed by ANOVA and post hoc Tukey tests (α = 0.05). The TBS values were significantly higher in the control group compared to the D1 and D2 groups (P < 0.05). Between DM groups, D2 values were significantly higher than those in the D1 group. Unlike DM groups, the zigzag fracture pattern was only noticed in the control group. DM adversely affected the TBS of dental composite resins to dentin; this negative effect is more exaggerated by type 1 DM than type 2 DM.

Performance evaluation of survival regression models in analysing Swedish dental implant complication data with frailty

The use of inappropriate methods for estimating the effects of covariates in survival data with frailty leads to erroneous conclusions in medical research. This study evaluated the performance of 13 survival regression models in assessing the factors associated with the timing of complications in implant-supported dental restorations in a Swedish cohort. Data were obtained from randomly selected cohort (n = 596) of Swedish patients provided with dental restorations supported in 2003. Patients were evaluated over 9 years of implant loss, peri-implantitis or technical complications. Best Model was identified using goodness, AIC and BIC. The loglikelihood, the AIC and BIC were consistently lower in flexible parametric model with frailty (df = 2) than other models. Adjusted hazard of implant complications was 45% (adjusted Hazard Ratio (aHR) = 1.449; 95% Confidence Interval (CI): 1.153-1.821, p = 0.001) higher among patients with periodontitis. While controlling for other variables, the hazard of implant complications was about 5 times (aHR = 4.641; 95% CI: 2.911-7.401, p<0.001) and 2 times (aHR = 2.338; 95% CI: 1.553-3.519, p<0.001) higher among patients with full- and partial-jaw restorations than those with single crowns. Flexible parametric survival model with frailty are the most suitable for modelling implant complications among the studied patients.