Three-year randomised clinical trial to evaluate the clinical performance, quantitative and qualitative wear patterns of hybrid composite restorations

The aim of the study was to compare the clinical performance, quantitative and qualitative wear patterns of conventional hybrid (Tetric Ceram), micro-filled hybrid (Gradia Direct Posterior) and nano-hybrid (Tetric EvoCeram, TEC) posterior composite restorations in a 3-year randomised clinical trial. Sixteen Tetric Ceram, 17 TEC and 16 Gradia Direct Posterior restorations were placed in human molars and evaluated at baseline, 6, 12, 24 and 36 months of clinical service according to US Public Health Service criteria. The gypsum replicas at each recall were used for 3D laser scanning to quantify wear, and the epoxy resin replicas were observed under scanning electron microscope to study the qualitative wear patterns. After 3 years of clinical service, the three hybrid restorative materials performed clinically well in posterior cavities. Within the observation period, the nano-hybrid and micro-hybrid restorations evolved better in polishability with improved surface gloss retention than the conventional hybrid counterpart. The three hybrid composites showed enamel-like vertical wear and cavity-size dependant volume loss magnitude. Qualitatively, while the micro-filled and nano-hybrid composite restorations exhibited signs of fatigue similar to the conventional hybrid composite restorations at heavy occlusal contact area, their light occlusal contact areas showed less surface pitting after 3 years of clinical service

Computer-aided designed/Computer-assisted manufactured composite resin versus ceramic single-tooth restorations: a 3-year clinical study

PURPOSE: No clinical evidence has been provided to suggest that metal-free all-composite resin indirect restorations are a functional and esthetic alternative to all-ceramic restorations. The aim of this study was to evaluate the clinical performance of single-tooth computer-aided design/computer-assisted manufacturing (CAD/CAM)-generated all-composite resin and all-ceramic crowns after 3 years of function. MATERIALS AND METHODS: In a prospective trial, 200 all-composite resin and all-ceramic crowns were rated over a 3-year period. Restorations were evaluated at 3 weeks and 1 and 3 years after insertion by the California Dental Association quality evaluation index, the patient's self-assessment, marginal fit, periodontal parameters, volume loss, and wear patterns of the veneering material. Statistical analysis was performed using t tests (a = .05). RESULTS: Cumulative survival and success rates after 3 years were 87.9% and 55.6% for all-composite resin and 97.2% and 81.2% for all-ceramic crowns, respectively (P < .05 for success rates). Restoration loosening occurred exclusively for all-composite resin crowns cemented on a cast post. All-ceramic restorations demonstrated satisfactory esthetic results. All-composite resin crowns resulted in significantly more mean total volume loss and mean vertical wear at occlusal contact areas after 6 months and 3 years of function. The clinical performance of the CAD/CAM-generated all-ceramic crowns used in this study was similar to that of other all-ceramic CAD/CAM systems. CONCLUSION: For up to 3 years of function, all-composite resin single-tooth restorations have inferior success rates compared to all-ceramic restorations. Due to the inferior esthetics and wear resistance of all-composite resin crowns, all-ceramic crowns remain the preferred treatment for CAD/CAM-generated metal-free single-tooth restorations.status: publishe

Nanohybrid and microfilled hybrid versus conventional hybrid composite restorations: 5-year clinical wear performance

The 5-year findings of a randomized clinical trial testing the null hypothesis that there are no differences between the clinical-wear performances of nano-, microfilled-, and conventional hybrids placed in class I and class II cavities are reported. Effects of subject-, operator-, and restoration-related variables on wear were assessed. Sixteen Tetric-C, 17 Tetric-EC, and 16 Gradia-DP restorations were placed in human molars and recalled at baseline, 6 months and at yearly intervals. The gypsum replicas at each recall were scanned (3D laser scanning), epoxy resin replicas were observed under scanning electron microscope and linear mixed models were used to study the influence of different variables on wear. The generalized vertical wear rate/month were (1.4 μm Tetric-C and Tetric-EC; 1.8 μm Gradia-DP) and volume wear rate/month were (0.017 mm(3) Tetric-EC; 0.018 mm(3) Gradia-DP, and 0.011 mm(3) Tetric-EC). Operator-cavity type interaction and surface area of restorations did significantly influence the volume wear rates (p < 0.05). The three wear patterns: fatigue cracks at heavy occlusal contact area/OCA, pitting at light OCA, and scratches/striations along the food escape pathways were evident. The three hybrids differed significantly in volume wear due to material and operator variables. Clinical relevance: Clinically, operators and cavity type can affect restorations' wear magnitude but do not contribute to increased functional risk of fracture or harmful effect on pulp and periodontal biocompatibility.status: publishe

The Gustatory Signaling Pathway and Bitter Taste Receptors Affect the Development of Obesity and Adipocyte Metabolism in Mice

Intestinal chemosensory signaling pathways involving the gustatory G-protein, gustducin, and bitter taste receptors (TAS2R) have been implicated in gut hormone release. Alterations in gut hormone profiles may contribute to the success of bariatric surgery. This study investigated the involvement of the gustatory signaling pathway in the development of diet-induced obesity and the therapeutic potential of targeting TAS2Rs to induce body weight loss. α-gustducin-deficient (α-gust-/-) mice became less obese than wild type (WT) mice when fed a high-fat diet (HFD). White adipose tissue (WAT) mass was lower in α-gust-/- mice due to increased heat production as a result of increases in brown adipose tissue (BAT) thermogenic activity, involving increased protein expression of uncoupling protein 1. Intra-gastric treatment of obese WT and α-gust-/- mice with the bitter agonists denatonium benzoate (DB) or quinine (Q) during 4 weeks resulted in an α-gustducin-dependent decrease in body weight gain associated with a decrease in food intake (DB), but not involving major changes in gut peptide release. Both WAT and 3T3-F442A pre-adipocytes express TAS2Rs. Treatment of pre-adipocytes with DB or Q decreased differentiation into mature adipocytes. In conclusion, interfering with the gustatory signaling pathway protects against the development of HFD-induced obesity presumably through promoting BAT activity. Intra-gastric bitter treatment inhibits weight gain, possibly by directly affecting adipocyte metabolism.status: publishe

The Gustatory Signaling Pathway and Bitter Taste Receptors Affect the Development of Obesity and Adipocyte Metabolism in Mice.

Intestinal chemosensory signaling pathways involving the gustatory G-protein, gustducin, and bitter taste receptors (TAS2R) have been implicated in gut hormone release. Alterations in gut hormone profiles may contribute to the success of bariatric surgery. This study investigated the involvement of the gustatory signaling pathway in the development of diet-induced obesity and the therapeutic potential of targeting TAS2Rs to induce body weight loss. α-gustducin-deficient (α-gust-/-) mice became less obese than wild type (WT) mice when fed a high-fat diet (HFD). White adipose tissue (WAT) mass was lower in α-gust-/- mice due to increased heat production as a result of increases in brown adipose tissue (BAT) thermogenic activity, involving increased protein expression of uncoupling protein 1. Intra-gastric treatment of obese WT and α-gust-/- mice with the bitter agonists denatonium benzoate (DB) or quinine (Q) during 4 weeks resulted in an α-gustducin-dependent decrease in body weight gain associated with a decrease in food intake (DB), but not involving major changes in gut peptide release. Both WAT and 3T3-F442A pre-adipocytes express TAS2Rs. Treatment of pre-adipocytes with DB or Q decreased differentiation into mature adipocytes. In conclusion, interfering with the gustatory signaling pathway protects against the development of HFD-induced obesity presumably through promoting BAT activity. Intra-gastric bitter treatment inhibits weight gain, possibly by directly affecting adipocyte metabolism

Effect of bitter agonists on differentiation of 3T3-F442A preadipocytes.

<p>(a) Representative Oil-Red O stained 3T3-F442A cells at day 12 of differentiation in the presence of vehicle, 150 μM DB or 100 μM Q. (b) Quantification of the Oil-Red O uptake at differentiation day 6 (n = 4) and 12 (n = 8). (c-d) Relative mRNA expression of the markers leptin and adiponectin during differentiation in the absence and presence of DB or Q (n = 6). (e) Trypan blue cell viability assay, presented as the amount of dead cells (% cells stained) after the 12-day differentiation period in the absence and presence of DB or Q (n = 3). **: P<0.01, ***: P<0.001 vehicle vs bitter.</p

Comparison of the energy balance during treatment with bitter agonists of obese WT and α-gust^-/- mice.

<p>(a-b) Changes in body weight during daily intra-gastric administration of water, DB (60 μmol/kg) or Q (160 μmol/kg) for 4 weeks in high-fat diet (15 weeks) obese (a) WT (n = 9–12) and (b) α-gust^-/- mice (n = 8–12). Results are expressed as percentage change from baseline, defined as the mean body weight measured during one week before the treatment. (c) Combined weight of gonadal, subcutaneous and mesenteric fat pads as percentage of total body weight of control or bitter treated WT (n = 9–12) and α-gust^-/- mice (n = 9–12), at sacrifice. (d) Relative mRNA expression of UCP1 in gonadal WAT of control or bitter treated WT (n = 7–9) and α-gust^-/- (n = 7–8) mice. (e-f) Changes in energy intake during the 4-week treatment period in (e) WT (n = 6–8) and (f) α-gust^-/- mice (n = 7–8), expressed as percentage change from baseline, defined as the mean energy intake measured during 9 days before the treatment. **: P<0.01; ***: P<0.001 water vs bitter; ##: P<0.01 treatment (water vs DB) x genotype.</p

Hypothalamic neuropeptide mRNA expression after treatment with bitter agonists of obese WT and α-gust^-/- mice.

<p>Relative hypothalamic AgRP (a), NPY (b) and POMC (c) mRNA expression levels in HFD-obese WT (n = 7–10) and α-gust^-/- (n = 6–9) mice after 4 weeks of daily gavage with water, DB or quinine. *: P<0.05 water vs DB or Q; #: P<0.05; ##<0.01 treatment (water vs DB) x genotype.</p

Comparison of the energy balance between WT and α-gust^-/- mice on a high fat diet.

<p>(a) Time course of body weight of WT (n = 16) and α-gust^-/- (n = 16) mice, on a high-fat diet for 19 weeks post-weaning. (b) Energy intake (kcal/day) of WT (n = 16) and α-gust^-/- (n = 16) mice during the last 4 weeks before sacrifice. (c-d) Relative hypothalamic AgRP and POMC mRNA levels in WT (n = 10) and α-gust^-/- (n = 9) mice after 19 weeks on a HFD. (e-f) Respiratory quotient and heat production, measured continuously during 1 week in WT (n = 8) and α-gust^-/- (n = 8) mice. *: P<0.05; **: P<0.01, ***: P<0.001 WT vs α-gust^-/-.</p

Difference in adiposity between high-fat diet (19 weeks) induced obese WT and α-gust^-/- mice.

<p>(a) The sum of gonadal, subcutaneous and mesenteric white adipose tissue mass as percentage of total body weight in WT (n = 16) and α-gust^-/- mice (n = 16). (b) Plasma leptin levels in WT (n = 10) and α-gust^-/- mice (n = 11). (c-e) Relative gonadal, subcutaneous and mesenteric fat UCP1 mRNA levels in WT (n = 6–9) and α-gust^-/- mice (n = 6–9). (f) Relative intrascapular brown adipose tissue UCP1 protein level expression in WT (n = 4) and α-gust^-/- mice (n = 4) as determined by Western blot. *: P<0.05, **: P<0.01, ***: P<0.001 WT vs α-gust^-/-.</p