Erbium laser in the debonding of ceramics: a literature review / Laser de érbio na remoção de cerâmicas: uma revisão de literatura

Background: The debonding of crowns and ceramic veneers with laser is already a reality in the clinic. It presents benefits in comparison to traditional removal with the use of a rotating instrument; however, there is still no consolidated protocol and many professionals use it without the necessary scientific basis. Objective: The aim of this work was to perform a literature review on the debonding of indirect ceramic restorations using the Er:YAG and Er,Cr:YSGG lasers to provide clinical professionals and the scientific community a careful analysis, and also to guiding the use of irradiation at laser for such procedures. Methods: Bibliographic searches were performed in the following databases: Pubmed, Web of Science and Google Scholar. According to the inclusion criteria adopted, twenty-seven clinical and in vitro studies were selected in the period from 2007 to 2021. In the present work, the composition of the crowns and facets, as well as the types of cement and the laser irradiation protocols adopted in the selected studies is detailed. Conclusions: It was concluded that the use of erbium lasers for debonding of indirect ceramic restorations proved to be more selective and conservative when compared to removal with a rotary diamond instrument. Furthermore, it was shown to be in more efficient in debonding different types of ceramics. However, there are great variations in the "debonding" protocols, which emphasizes the need for further studies that seek to standardize the irradiation protocols considering the different clinical situations (AU)

Antecedentes: A remoção de coroas e facetas cerâmicas com laser já é uma realidade clínica e apresenta benefícios em relação à remoção tradicional com uso de instrumento rotatório diamantado; entretanto, ainda não existe um protocolo consolidado e muitos profissionais o utilizam sem o embasamento científico necessário. Objetivos: O objetivo deste trabalho foi realizar uma revisão da literatura sobre a remoção de restaurações cerâmicas indiretas utilizando os lasers Er:YAG e Er,Cr:YSGG para fornecer uma análise cuidadosa aos profissionais clínicos e à comunidade científica, além de orientar o uso da irradiação a laser para tal aplicação. Métodos: As buscas bibliográficas foram realizadas, nas seguintes bases de dados: Pubmed, Web of Science e Google Scholar. De acordo com os critérios de inclusão adotados, foram selecionados vinte e sete estudos clínicos e in vitro no período de 2007 a 2021. No presente trabalho, a composição das coroas e facetas, bem como os tipos de cimento e os protocolos de irradiação laser adotados nos estudos selecionados foram detalhados. Conclusão: Concluiu-se que o uso dos lasers de érbio para remoção de restaurações cerâmicas indiretas mostrou-se mais seletivo e conservador quando comparado à remoção com instrumento rotatório diamantado, além de ser eficiente na remoção de diferentes tipos de cerâmicas. No entanto, existem grandes variações nos protocolos de "debonding", o que enfatiza a necessidade de novos estudos que busquem uma padronização dos protocolos de irradiação considerando as diferentes situações clínicas.(AU)

Morphological, optical, and elemental analysis of dental enamel after debonding laminate veneer with Er,Cr:YSGG laser: A pilot study.

Laminate veneer removal is becoming a routine procedure at the dental clinic and the use of laser can facilitate its removal. This work aimed to evaluate the morphological, elemental, and optical changes in the remaining enamel after veneer removal using Er,Cr:YSGG laser. Forty-four enamel slabs were prepared and randomly distributed into nine experimental groups, for bonding using lithium disilicate laminates with three different luting agents (Variolink Veneer, RelyX U200, and RelyX Veneer). Then each agent was debonded using Er,Cr:YSGG laser (2.78 µm) using two different protocols:3.5 W, 48.14 J/cm2 , 20 Hz non-contact and 3.0 W, 48.14 J/cm2 , 20 Hz non-contact. The morphological, optical, and elemental analysis of enamel was performed before cementation and after laser debonding, using scanning electron microscopy (SEM), optical coherence tomography (OCT), and energy-dispersive X-ray spectroscopy (EDS). The level of statistical significance adopted was 5%. The EDS analysis of enamel after debonding revealed a significant increase in silane and carbon, as well as a decrease in calcium and phosphate contents. Analysis showed the presence of residual cement in most experimental groups but the morphological analysis showed alteration of the enamel's prisms only in the groups that used RelyX Veneer and Variolink Veneer cements. There was no evidence of deleterious morphological changes resulting from irradiation. However, an increase in the optical attenuation coefficient by the OCT was observed due to the presence of the remaining cement. It can be concluded that the Er,Cr:YSGG laser, in the mean powers used, is efficient for veneer removal without causing deleterious effects for the enamel.