ABSTRACT
OBJECTIVES: To compare the clinical wear performance of nanofilled restorations (Filtek Supreme) against microhybrid restorations (Z100) in a 5-year randomized clinical trial to evaluate the wear rate and the influence of subject-, operator- and restoration-related variables on wear rate. MATERIALS AND METHODS: 18 Filtek Supreme and 17 Z100 restorations were placed in human molars (split-mouth-model) and bonded with Single Bond/Scotch Bond Adhesive. Restorations were recalled at baseline, 6-, 12-months and at annual intervals until 5-years of clinical service. The gypsum replicas at each recall were used for 3D-Pro-laser scanning to quantify wear and the epoxy resin replicas were observed under SEM for microwear patterns. Linear-mixed-models were used to study the influence of the different variables on the vertical and volume loss. RESULTS: Volume wear, but not the vertical wear rate of the two restorative materials were significantly influenced (p<0.05) by the factors such as operator, cavity type, as well as combination of operator-cavity type and quadrant type. The variations in the occlusal surface microwear patterns over time reflect the effect of biomechanics of mastication on the restorative composite. CONCLUSIONS: The rate of vertical and volume loss of both the restoratives appear, on average, not to be constant even after the early stage wear, under the influence of certain clinical variables.
Subject(s)
Composite Resins , Dental Restoration Wear , Dental Restoration, Permanent/methods , Adult , Dental Bonding/methods , Dental Cavity Preparation , Female , Humans , Linear Models , Male , Microscopy, Electron, Scanning , Models, Dental , Molar , Nanocomposites , Particle Size , Resin Cements , Silicon Dioxide , Subtraction Technique , Young Adult , ZirconiumABSTRACT
OBJECTIVES: Compare the 3-year clinical performance (wear as an additional parameter) of a nanocomposite and a microhybrid composite, versus ADA guidelines (2001) using direct (clinical/USPHS) and indirect (quantitative/3D laser scan and qualitative/SEM) methods, in parallel. MATERIALS AND METHODS: 18 Filtek Supreme and 17 Z100 restorations were placed in molars (split mouth model) and bonded with Single bond Adhesive. Restorations were evaluated at baseline and 6-, 12-, 24-, 36-months of clinical service according to modified USPHS criteria. The gypsum replicas at each recall were used for 3D-Pro-laser scanning to quantify wear and the epoxy resin replicas were observed under SEM to study the qualitative wear patterns. Repaired restorations were considered functionally present and not failed. Restorations were judged as failed, whenever completely replaced or when scored Delta due to material related factors impairing clinical function. RESULTS: Filtek Supreme appeared better polishable than Z100 (p=0.0078; McNemar test). However, there were no significant differences between groups for other criteria including wear (p>0.05; Mann-Whitney U test). Qualitatively, fatigue wear at heavy occlusal contact areas (OCA), pitting at light OCA and scratches/striations along the food escape pathways were evident in almost all worn surfaces under SEM. CONCLUSIONS: At 3 years, nanocomposite and microhybrid composite meet ADA Acceptance Guidelines (2001) for tooth-colored restorative materials for posterior teeth.
Subject(s)
Composite Resins/chemistry , Dental Materials/chemistry , Dental Restoration Wear , Dental Restoration, Permanent/standards , Nanocomposites/chemistry , Adult , Bisphenol A-Glycidyl Methacrylate/chemistry , Color , Dental Bonding , Dental Cavity Preparation/classification , Dental Cavity Preparation/methods , Dental Marginal Adaptation , Dental Polishing , Dental Prosthesis Repair , Dental Restoration Failure , Dentin-Bonding Agents/chemistry , Female , Follow-Up Studies , Humans , Lasers , Male , Microscopy, Electron, Scanning , Molar/pathology , Resin Cements/chemistry , Silicon Dioxide/chemistry , Surface Properties , Zirconium/chemistryABSTRACT
In light of the current trend towards "minimal invasive" dentistry, diverse cavity preparation techniques have been introduced as an alternative or addition to common bur instrumentation. This study investigated whether diamond sonoabrasion (SonicSys Micro, Kavo), air abrasion (Prep Start, Danville) and Er:YAG laser irradiation (Fidelis) produce surfaces at enamel/dentin that are equally receptive to bonding as traditional mid-grit diamond-bur (Komet) and 600-grit SiC-paper prepared surfaces, of which the latter two served as controls. An etch&rinse adhesive (OptiBond FL, Kerr) applied with and without prior acid-etching and a self-etch adhesive (Clearfil SE, Kuraray) were employed to bond the restorative composite (Z100, 3M ESPE) to the diversely prepared enamel and dentin surfaces. The microtensile bond strength (microTBS) was determined after 24 hours of storage in water at 37 degrees C. The results indicated that the manner of preparation of enamel and dentin prior to bonding procedures significantly influenced the bonding effectiveness of both the etch&rinse and the self-etch adhesive. Using an etch&rinse adhesive, separate acid-etching of air-abraded and Er:YAG-irradiated enamel and dentin surfaces remains mandatory. Bonding to diamond-sonoabraded and air-abraded enamel and dentin was, in general, not different from bonding to conventional diamond-bur prepared surfaces, whereas, bonding to Er:YAG-irradiated enamel and dentin surfaces in general resulted in a significantly lower bonding effectiveness compared to bonding to diamond-bur prepared surfaces.
