title: Transdental photo-activation technique: hardness and marginal adaptation of composite restorations using different light sources.
abstract: This study investigated the influence of different light sources associated with a transdental photoactivation technique on the marginal adaptation and hardness of composite restorations. Cavities (3 mm wide x 3 mm long x 1.5 mm in deep) were prepared on flattened bovine dentin and filled with Z250 composite (3M ESPE). Nine groups (n=10) were defined according to the curing technique (direct; transdental--photo-activation through 1 mm of enamel and 2 mm of dentin; mixed--transdental + direct) and light source (QTH XL2500, 3M ESPE; PAC Apollo 95E, DMD; LED Ultrablue Is, DMC) combination. Marginal adaptation was evaluated using a dye staining method, and the percentage of stained margins was recorded. Knoop Hardness readings were made across the transversal section of the fillings. Data were submitted to two-way ANOVA and Tukey's test (p< or =0.05). For margin analysis, although none of the curing conditions provided perfect adaptation, the mixed technique showed lower gap formation. No significant differences were detected between the transdental and other techniques, and no significant differences were detected among the light sources. For hardness, the direct technique showed slightly greater hardness than the mixed technique. Also, the mixed technique yielded greater hardness than the transdental technique. Among the light sources, the LED showed greater hardness than the PAC; whereas, no significant differences between the QTH and other sources were detected. The mixed technique might improve the marginal adaptation of restorations, while not being detrimental to composite hardness.
authors.affiliation: Department of Restorative Dentistry, Dental Materials Area, Piracicaba School of Dentistry, State University of Campinas, Piracicaba, SP, Brazil.
authors.forename: Eliane Bemerguy
authors.initials: EB
authors.lastname: Alves
authors.forename: Roberta Caroline Bruschi
authors.initials: RC
authors.lastname: Alonso
authors.forename: Gisele Maria
authors.initials: GM
authors.lastname: Correr
authors.forename: Américo Bortolazzo
authors.initials: AB
authors.lastname: Correr
authors.forename: Rafael Ratto
authors.initials: RR
authors.lastname: de Moraes
authors.forename: Mário Alexandre Coelho
authors.initials: MA
authors.lastname: Sinhoreti
authors.forename: Lourenço
authors.initials: L
authors.lastname: Correr-Sobrinho
mesh_terms: D000818:Animals; D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry / Q000528:radiation effects; D002417:Cattle; D003188:Composite Resins / Q000737:chemistry / Q000528:radiation effects*; D003737:Dental Cavity Preparation / Q000145:classification; D003743:Dental Enamel / Q000033:anatomy & histology; D018772:Dental Marginal Adaptation; D003764:Dental Materials / Q000737:chemistry / Q000528:radiation effects*; D003793:Dental Restoration, Permanent / Q000295:instrumentation* / Q000379:methods; D003804:Dentin / Q000033:anatomy & histology; D017220:Dentin-Bonding Agents / Q000737:chemistry / Q000528:radiation effects; D005456:Fluorescent Dyes; D006244:Hardness; D008027:Light; D008029:Lighting / Q000295:instrumentation*; D008422:Materials Testing; D011409:Propylene Glycols; D011897:Random Allocation; D012235:Rhodamines; D013696:Temperature; D013997:Time Factors; D014867:Water / Q000737:chemistry
chemical_list: C089090:Caries Detector; D003188:Composite Resins; D003764:Dental Materials; D017220:Dentin-Bonding Agents; C444701:Filtek Z250; D005456:Fluorescent Dyes; D011409:Propylene Glycols; D012235:Rhodamines; C115612:single bond; D014867:Water; D017438:Bisphenol A-Glycidyl Methacrylate