Influence of Nd:YAG laser on intrapulpal temperature and bond strength of human dentin under simulated pulpal pressure.
The aim of this study was to evaluate the effects of simulated pulpal pressure (SPP) on the variation of intrapulpal temperature (ΔT) and microtensile bond strength (μTBS) to dentin submitted to an adhesive technique using laser irradiation. One hundred sound human molars were randomly divided into two groups (n = 50), according to the presence or absence of SPP (15 cm H2O). Each group was divided into five subgroups (n = 10) according to Nd:YAG laser energy (60, 80, 100, 120, 140 mJ/pulse). The samples were sequentially treated with the following: 37 % phosphoric acid, adhesive (Scotchbond Universal), irradiation with Nd:YAG laser (60 s), and light curing (10 s). ΔT was evaluated during laser irradiation using a type K thermocouple. Next, a composite resin block was build up onto the irradiated area. After 48 h, samples were submitted to microtensile test (10 kgf load cell, 0.5 mm/min). Data were analyzed by two-way ANOVA and Tukey tests (p = 0.05). ANOVA revealed significant differences for ΔT and TBS in the presence of SPP. For ΔT, the highest mean (14.3 ± 3.23 °C)(A) was observed in 140 mJ and without SPP. For μTBS, the highest mean (33.4 ± 4.15 MPa)(A) was observed in 140 mJ and without SPP. SPP significantly reduced both ΔT and μTBS during adhesive procedures, lower laser energy parameters resulted in smaller ΔT, and the laser parameters did not influence the μTBS values.
Department of Restorative Dentistry, Institute of Science and Technology of São José dos Campos, UNESP-Univ Estadual Paulista, Avenida Engenheiro Francisco José Longo, 777, Jardim São Dimas, São José dos Campos, SP, CEP: 12245-000, Brazil. tania.silva@ict.unesp.br.
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Silva
Department of Restorative Dentistry, Institute of Science and Technology of São José dos Campos, UNESP-Univ Estadual Paulista, Avenida Engenheiro Francisco José Longo, 777, Jardim São Dimas, São José dos Campos, SP, CEP: 12245-000, Brazil. dralucelialemes@hotmail.com.
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Gonçalves
Department of Restorative Dentistry, Institute of Science and Technology of São José dos Campos, UNESP-Univ Estadual Paulista, Avenida Engenheiro Francisco José Longo, 777, Jardim São Dimas, São José dos Campos, SP, CEP: 12245-000, Brazil. beatrizmfonseca@bol.com.br.
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Fonseca
Department of Restorative Dentistry, Institute of Science and Technology of São José dos Campos, UNESP-Univ Estadual Paulista, Avenida Engenheiro Francisco José Longo, 777, Jardim São Dimas, São José dos Campos, SP, CEP: 12245-000, Brazil. stellarmse@gmail.com.
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Esteves
Department of Restorative Dentistry, Institute of Science and Technology of São José dos Campos, UNESP-Univ Estadual Paulista, Avenida Engenheiro Francisco José Longo, 777, Jardim São Dimas, São José dos Campos, SP, CEP: 12245-000, Brazil. daphnecbarcellos@hotmail.com.
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Barcellos
Optical Surface Measurements Labs, Institute for Advanced Studies (IEAv), Aerospace Technical Center (CTA), Trevo Coronel Aviador José Alberto Albano do Amarante, 01, Putim, São José dos Campos, SP, Brazil. damiao@ieav.cta.br.
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Damião
Department of Restorative Dentistry, Institute of Science and Technology of São José dos Campos, UNESP-Univ Estadual Paulista, Avenida Engenheiro Francisco José Longo, 777, Jardim São Dimas, São José dos Campos, SP, CEP: 12245-000, Brazil. sergio@ict.unesp.br.
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Gonçalves
D000268:Adhesiveness; D003188:Composite Resins / Q000737:chemistry; D055117:Curing Lights, Dental; D003782:Dental Pulp; D003804:Dentin / Q000737:chemistry* / Q000528:radiation effects*; D006801:Humans; D053844:Lasers, Solid-State; D011312:Pressure; D013696:Temperature; D013718:Tensile Strength
D003188:Composite Resins
Adhesion; Intrapulpal pressure; Nd:YAG laser; Temperature