This study compared the fracture resistance of monolithic and veneered all-ceramic four-unit posterior fixed dental prostheses (FDPs) generated by computer-aided design/computer-aided manufacturing (CAD/CAM) after aging in a mastication simulator. Four-unit FDPs were designed from six different all-ceramic systems: 1) monolithic lithium disilicate (M-E), 2) monolithic zirconia (M-TZI), 3) veneered zirconia by conventional layering (V-L), 4) veneered zirconia by lithium disilicate pressing (V-P), 5) veneered zirconia by lithium disilicate fusing (CAD-F-E), and 6) veneered zirconia by feldspathic ceramic cementing (CAD-C-CB). The specimens were divided into control and aging groups (n = 10 per group). The aging process included both thermocycling and mechanical loading and was followed by fracture resistance testing. All specimens in the M-E, M-TZI, and V-L groups survived; however, all specimens in the V-P group were fractured during artificial aging. The highest fracture resistance values were observed in the M-TZI group. According to the fracture resistance test, connector fractures were the most frequent type of failure. M-TZI and M-E FDPs revealed no failures during aging and showed higher fracture resistance than the veneered groups. Among the veneered zirconia framework groups, V-L FDPs showed the highest success rate during aging, while the fracture resistance was similar among all the veneered zirconia groups.
Dry mouth, caused by decreased salivary gland function and/or weak salivary stimulation, can severely affect oral health in older individuals. Therefore, the aim of this study is to evaluate whether a lip trainer device and sonic toothbrush can improve salivary flow and oral wetness in older patients complaining of dry mouth. Overall, 39 subjects aged ≥60 years who had at least 20 natural teeth were randomly assigned to use a lip trainer device (group P, n = 13) or a sonic toothbrush (group S, n = 13). The subjects who did not experience oral dryness were included as controls (group C; n = 13). The unstimulated and stimulated salivary flow rates and oral wetness were measured at baseline, 1 and 6 months. The unstimulated salivary flow significantly increased in both groups at 1 and 6 months (P < 0.05). The stimulated salivary flow was also significantly increased in group P (P < 0.01) compared with the level at baseline. However, no significant difference was observed over time in group S. Oral wetness of the tongue and buccal mucosa in group P had significantly improved at 1 and 6 months (P < 0.05). Dry mouth in older individuals may be improved by using a lip trainer device or a sonic toothbrush.
The present study aimed to assess the effects of a multimicronutrient food supplement on periodontal clinical parameters and systemic/local inflammatory markers. Thirty patients with severe chronic periodontitis who adhered to the Mediterranean diet (MD) underwent non-surgical therapy and daily took either the micronutrient complex (group-A) or olive oil (group-B) from baseline (T0) to 3 months (T2). Supragingival debridement was performed at T0. One month later (T1), one-stage-full-mouth disinfection was performed. Periodontal clinical parameters were monitored and correlated with serum C-reactive protein (CRP) and salivary matrix metalloproteinase-8/9 (MMPs-8/9) quantified at each time point. Longitudinal analysis revealed that in group-A, the MMP-8/-9 levels were decreased at T2 compared with at T0 (P = 0.013 and P = 0.004, respectively) and that the MMP-9 levels were decreased at T1 (P = 0.004). These reductions were not significant in group-B. The CRP levels in both groups did not change over time. No between-group differences were noted for any parameter. The correlation between the full-mouth bleeding score and the MMP-8 level in both groups was significant (P < 0.001). The investigated local and systemic inflammatory parameters were not affected by the tested multimicronutrient supplement in patients who adhered to MD. In conclusion, MMP-8 is useful for assessing the reduction in periodontal inflammation.
This study investigated the handling properties and clinical performance of two commercially available resin materials with slight differences in filler composition for the fabrication of fixed interim restorations. In a dental university setting, patients requiring prosthetic treatment were supplied with fixed interim restorations fabricated from two commercially available resin materials. To clarify the handling properties of the resin materials, dentists and undergraduate students completed a questionnaire. Prior to insertion of the definitive restoration, the interim restorations were analyzed by calibrated examiners using a modification of the United States Public Health Service criteria. Eighty-two fixed interim restorations with a mean clinical service period of 44.5 (±28.3) days were included, including 39 single crowns, 30 fixed denture prostheses, 10 blocked crowns, and 3 partial coverage restorations. No significant differences between the two materials in the rating of their handling properties were identified, with the exception of the parameter “surface”. Failures due to fractures were observed in 13% of the interim restorations. No significant differences between the materials in the rating of the clinical performance were identified. These results indicate that slight changes in the filler composition of commercial formulations account for few differences in handling properties and clinical performance.