Purpose To systematically review studies on various materials and methods used for wear testing of occlusal devices and their antagonists in vitro and in vivo. Methods An electronic search in OVID, Web of Science, PubMed and Scopus was conducted using the following terms (MeSH words) with any synonyms and closed terms: “Splint*” OR “occlusal splint*” OR “night guard” OR “occlusal device” OR “occlusal devices” OR “deprogrammer” OR “bite splint” OR “bite plane” OR “orthotic appliance*” OR “orthotic devices” AND “wear” OR “two‐body wear” OR “three‐body wear” OR “tooth wear” OR “wear measurement*” OR “wear behaviour” OR “wear behavior” OR “abrasion” AND “Polymethyl Methacrylate” OR “PMMA” OR “acrylic resin*” OR “dental material*” OR “dental enamel” OR “CAD” OR “CAM” OR “PEEK” OR “material* testing”. Database search was limited to English‐language publications and published between 2001 and 1st of September 2021. A further hand search was done to ensure all materials were captured. Results After the removal of duplicates, 115 studies were identified, and 11 were chosen for review. Studies showed that the lowest volumetric loss was observed in PEEK occlusal device materials, whereas heat‐cure, CAD‐milled, and 3D printed occlusal device materials had no significant difference in wear. Vacuum‐formed materials showed the highest wear among all groups. Testing parameters were found to be inconsistent across all studies. Conclusion There is a need for standardization of in vitro and in vivo wear measurement and testing protocols as this study revealed a wide variety of testing protocols which potentially could influence the outcome. Polishing procedures are required for the material. Limited studies are available on 3D printed occlusal device materials and would therefore require further investigation, especially on printing build angles and settings. Further clinical studies would be advantageous to provide guidance on the selection of the best occlusal device material that would last the longest without remake.

No abstract

Objectives The aim of this study was to assess the effect of light curing intensity and wavelength spectrum on heat generation and chemomechanical properties of bulk-fill composites. Methods Four bulk-fill restorative materials (Filtek bulk-fill, Tetric PowerFill bulk-fill, Beautifil Bulk restorative and Admira Fusion X-tra were used in this study. A total of 100 cylindrical specimens of each composite ( n = 25/group) were prepared, then cured using monowave light curing unit (LCU) with a single light intensity of 1470 mW/cm 2 , and polywave LCU with three different light intensities (1200,2100, 3050mW/cm 2 ). The temperature change during polymerisation was measured by five K-type thermocouples placed in each 1 mm layer from top to bottom. Hardness and degree of conversion of composites at each level were evaluated. Results were statistically analysed. Results The use of polywave LCU resulted in statistically higher peak temperatures ranging between 31.4–63.5 °C compared to the temperature generated by monowave LCU ranging between 29.5–60 °C ( p < .05). Curing using polywave LCU with the highest light intensity of 3050 mW/cm 2 caused the highest peak temperature irrespective of the composite types. There was no significant difference in hardness with different light curing intensities and curing times, regardless of the bulk-fill resin materials ( p > .05). A positive correlation was also found between the hardness and the DoC of the four bulk-fill composites. Conclusion The change in temperature during polymerisation of bulk-fill composites were found to be proportional to the increase in light curing intensity. Mechanical properties of the bulk-fill composites were dependent on the composition and the type of photoinitiators.

No abstract

No abstract