title: Ex-vivo evaluation of the intrapulpal temperature variation and fracture strength in teeth subjected to different external bleaching protocols.
abstract: This study evaluated the influence of bleaching protocols on intrapulpal temperature and fracture strength of the bleached teeth. Ninety maxillary incisors were assigned to 9 groups (n=10): G1: 35% carbamide peroxide (35% CP), G2: 38% hydrogen peroxide (38% HP), G3: halogen light, G4: LED-laser, G5: 35% CP + halogen light, G6: 38% HP + halogen light, G7: 35% CP + LED-laser, G8: 38% HP + LED-laser, and G9: no treatment (control). Pulp space was widened, a thermocouple was introduced through the apex up to the pulp chamber and the temperature was recorded (°C). The fracture strength (kN) was determined using an Instron machine. Data were analyzed by ANOVA and Tukey's test (p<0.05). The halogen light alone (1.10 ± 0.24) (G3) and associated with 38% HP (1.15 ± 0.30) (G6) produced the highest temperature increase, statistically different (p<0.05) from the other groups. G1 (0.15 ± 0.06) and G6 (0.19 ± 0.07) produced the lowest values, statistically different (p<0.05) from G5 (0.65 ± 0.49). The bleaching protocols increased the temperature, but no increment exceeded the critical value of 5.6°C. Neither 35% CP nor 38% HP or the light sources alone altered the fracture strength of the teeth.
authors.affiliation: University of Ribeirão Preto, Dental School, SP, Brazil.
authors.forename: Renata Araújo
authors.initials: RA
authors.lastname: Coelho
authors.forename: Alcides Gomes
authors.initials: AG
authors.lastname: Oliveira
authors.forename: Aline Evangelista
authors.initials: AE
authors.lastname: Souza-Gabriel
authors.forename: Silvio Rocha C
authors.initials: SR
authors.lastname: Silva
authors.forename: Yara T Correa
authors.initials: YT
authors.lastname: Silva-Sousa
authors.forename: Ricardo Gariba
authors.initials: RG
authors.lastname: Silva
mesh_terms: D001831:Body Temperature / Q000187:drug effects*; D000077463:Carbamide Peroxide; D055117:Curing Lights, Dental; D003782:Dental Pulp / Q000187:drug effects* / Q000502:physiology; D003799:Dental Stress Analysis; D006801:Humans; D006861:Hydrogen Peroxide / Q000008:administration & dosage; D007180:Incisor / Q000187:drug effects; D054023:Lasers, Semiconductor; D008437:Maxilla; D010545:Peroxides / Q000008:administration & dosage; D014073:Tooth Bleaching / Q000009:adverse effects / Q000379:methods*; D058205:Tooth Bleaching Agents / Q000008:administration & dosage* / Q000009:adverse effects; D014082:Tooth Fractures / Q000209:etiology / Q000517:prevention & control*; D014508:Urea / Q000008:administration & dosage / Q000031:analogs & derivatives
chemical_list: D010545:Peroxides; D058205:Tooth Bleaching Agents; D000077463:Carbamide Peroxide; D014508:Urea; D006861:Hydrogen Peroxide