An increased incidence of fracture has been reported in teeth where root canals were treated with calcium hydroxide. Edge chipping is one test used to measure the resistance of brittle materials to fracture. Presently, no studies have reported on edge chipping in teeth. This study evaluated the fracture resistance of human dentin exposed to calcium hydroxide for up to 60 days using the edge chi...

Rotary ultrasonic machining (RUM) is a relatively low cost and environmentally benign process for machining of advanced ceramics. Much effort has been made to theoretically and experimentally investigate material removal rate, surface roughness, and tool wear in RUM. However, there is no report on systematic study of edge chipping in RUM drilling of ceramics. This paper presents the results of ...

One of the most frequent fracture modes in teeth is chipping. It can lead to deterioration and ultimate loss of tooth function. Chips in enamel can also be used to gain insight into the evolutionary history of extant animal and fossil hominin species. In this study, chipping tests are performed on the surfaces of as-received or flattened human molars using hard indenters. The chips exhibit a ch...

The objective of this study is to evaluate the existing test methods of die strength, including widelyaccepted three-point and four-point bending tests, and a newly-proposed point-load test by testing silicon die specimens with different surface conditions. It has been reported that there are three factors to influence die strength: the surface conditions of the die (including grinding-mark dir...

Surface quality including surface roughness and edge chipping is a key process measure in micro ultrasonic machining (Micro-USM) as an efficient process for micromachining of hard and brittle materials. Process parameters such as ultrasonic vibration amplitude, static load, type of tool material, type and size of abrasive particles and slurry concentration can influence the surface quality. How...