Prognostic factors affecting the duration of disability after third molar removal.

PURPOSE: The purposes of this investigation were 1) to estimate the duration of disability after third molar removal and 2) to identify factors associated with prolonged recovery. MATERIALS AND METHODS: This was a prospective cohort study composed of subjects enrolled in the American Association of Oral and Maxillofacial Surgeons Age-Related Third Molar Study. The predictor variables were grouped as follows: demographic, health status, anatomic, pathologic, medications, and complications. The outcome variable was the duration of postoperative disability measured as the number of days the subject reported inability to perform normal daily activities after third molar removal. Bivariate and multiple linear regression analyses were used. The level of statistical significance was P < .05. RESULTS: The study sample included 4,004 subjects who had 8,748 third molars removed. The mean duration of postoperative disability was 1.4 ± 1.8 days (range, 0-26; median, 1 day). In the multiple linear regression model, age, female gender, number of third molars removed, mandibular third molar removal, full-bony impaction, sum of antibiotics or pain medications, and complications were associated with prolonged recovery (P < .05). Erupted third molars, periodontal disease or other preoperative pathology, and use of chlorhexidine were associated with earlier return to normal daily activities (P < .05). CONCLUSION: The study results suggest that third molar removal is associated with a mean delay in returning to normal activities of less than 2 days. Several factors were statistically associated with time to return to normal activities.

Effect of liquid rubber additions on physical properties of Bis-GMA based dental resins.

OBJECTIVE: The aim of this investigation was to determine the effect of an experimental liquid rubber (LR) toughening agent on fracture toughness, crosslink density and Barcol hardness of polymerized mixtures of 50/50 wt% Bis-GMA and TEGDMA. METHODS: An experimental LR, was added to a solution of Bis-GMA and TEGDMA containing 1wt% dimethylamino ethyl methacrylate and 0.5 wt% camphoroquinone at concentrations 0-10%. The composites were polymerized by exposure to a visible light curing unit for 60s. Fracture toughness was determined according to ASTM. 399. Crosslink density was evaluated using a swell test in ethanol. RESULTS: Mean fracture toughness values ranged from 0.39 MPa m(1/2) for samples containing 6% to 1.24 MPa m(1/2) for samples containing 8% LR. Fracture toughness of samples containing 2%, 4%, and 8% LR were significantly higher than controls. The highest degree of cross-linkage was obtained in controls and lowest for samples containing 2% LR. Barcol Hardness values ranged from 36.7 for the control and 4% LR composition to 31.2 for samples containing 10% LR. SIGNIFICANCE: Addition of 2, 4 and 8% LR increases the fracture toughness of Bis-GMA/TEGDMA composites. Addition of LR shows promise as a method of improving the fracture toughness of Bis-GMA based dental composites.