Debonding Time and Dental Pulp Temperature With the Er, Cr: YSGG Laser for Debonding Feldespathic and Lithium Disilicate Veneers

The removal of ceramic veneers is a time-consuming procedure in a dentaloffice. Little research has been done in alternative removal techniques for ceramic veneers.The objective of this study was to evaluate the removal of feldspathic and lithium disilicatereinforced glass ceramic veneers by Er, Cr: YSGG and to measure debonding time and pulpaltemperature increase during veneer removal. Fifty-seven bovine incisor teeth were prepared and divided into 3 groups. Ceramicspecimens with a thickness of 0.7mm, a width of 4mm and a length of 8 mm were fabricatedfrom feldspathic ceramic, lithium disilicate reinforced glass ceramic HT (high translucency) andlithium disilicate reinforced glass ceramic MO (medium opacity) (19 for each group). Specimenswere cemented on the labial surface of incisors using resin cement. The Er, Cr: YSGG laserwas applied to each specimen at 2.5 W and 25 Hz. Debonding time was measured for eachspecimen, and the intrapulpal temperature was detected in 3 specimens for each group. Datawere analyzed via one-way analysis of variance (ANOVA) at significance level of 0.05 (α = 0.05). Mean debonding time was 103.68 (26.76), 106.58 (47.22) and 103.84 (32.90) secondsfor feldspathic, lithium disilicate MO, and lithium disilicate HT respectively. There was nosignificant statistical difference among the groups (P value = 0.96). The intrapulpal temperatureincrease was less than 1°C in all groups. Er, Cr: YSGG can successfully be used to efficiently debond feldspathic and lithiumdisilicate reinforced glass ceramic veneers. There was no significant difference for debondingtime among these ceramic materials. During ceramic laminate veneer removal by laserirradiation, no irritating temperature rise was detected.