Influence of pulse repetition rate on temperature rise and working time during composite filling removal with the Er : YAG laser


Autoria(s): CORREA-AFONSO, Alessandra M.; PECORA, Jesus Djalma; PALMA-DIBB, Regina G.
Contribuinte(s)

UNIVERSIDADE DE SÃO PAULO

Data(s)

18/04/2012

18/04/2012

2008

Resumo

Objective: The purpose of this study was to assess the efficacy of Er:YAG laser energy for composite resin removal and the influence of pulse repetition rate on the thermal alterations occurring during laser ablation. Materials and Methods: Composite resin filling was placed in cavities (1.0 mm deep) prepared in bovine teeth and the specimens were randomly assigned to five groups according to the technique used for composite filling removal. In group I (controls), the restorations were removed using a high-speed diamond bur. In the other groups, the composite fillings were removed using an Er: YAG laser with different pulse repetition rates: group 2-2 Hz; group 3-4 Hz; group 4-6 Hz; and group 5-10 Hz. The time required for complete removal of the restorative material and the temperature changes were recorded. Results: Temperature rise during composite resin removal with the Er: YAG laser occurred in the substrate underneath the restoration and was directly proportional to the increase in pulse repetition rate. None of the groups had a temperature increase during composite filling removal of more than 5.6 degrees C, which is considered the critical point above which irreversible thermal damage to the pulp may result. Regarding the time for composite filling removal, all the laser-ablated groups (except for group 5 [10 Hz]) required more time than the control group for complete elimination of the material from the cavity walls. Conclusion: Under the tested conditions, Er: YAG laser irradiation was efficient for composite resin ablation and did not cause a temperature increase above the limit considered safe for the pulp. Among the tested pulse repetition rates, 6 Hz produced minimal temperature change compared to the control group (high-speed bur), and allowed composite filling removal within a time period that is acceptable for clinical conditions.

Identificador

PHOTOMEDICINE AND LASER SURGERY, v.26, n.3, p.221-225, 2008

1549-5418

http://producao.usp.br/handle/BDPI/15507

10.1089/pho.2007.2120

http://dx.doi.org/10.1089/pho.2007.2120

Idioma(s)

eng

Publicador

MARY ANN LIEBERT INC

Relação

Photomedicine and Laser Surgery

Direitos

closedAccess

Copyright MARY ANN LIEBERT INC

Palavras-Chave #CAVITY PREPARATION #ABLATION RATE #DENTIN #Surgery
Tipo

article

original article

publishedVersion