Effect of cigarette smoke on the physical and chemical properties of the enamel and dentin and bond strength to resin composite using different adhesive systems

Author(s)

Jéssica Dias Theobaldo

• Document type: Master's Dissertation
• Press: Piracicaba, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Faculdade de Odontologia de Piracicaba
• Defense date: 2015-02-23

Examining board members

Flavio Henrique Baggio Aguiar; Roberta Tarkany Basting; Giselle Maria Marchi

• Advisor: Flavio Henrique Baggio Aguiar

Abstract

This study evaluated the effect of cigarette smoke on physico-chemical properties of enamel and dentin and bond strength to resin composite using different adhesive systems. For this, it was divided into two studies. Study 1 evaluated the influence of exposure to smoke (20 cigarettes per day for 5 days) and pH cycling (8 day cycle) in the chemical composition and surface and cross-sectional microhardness of dental substrate. 40 bovine dental fragments (enamel and dentin) were allocated into 4 groups (n=10): Control- without any treatment, CS- exposure to cigarette smoke, PC- pH cycling and CS-PC- exposure to smoke and pH cycling. After that, samples are subjected to X¿Ray Microfluorescence, X¿Ray Fluorescence and surface and cross-sectional microhardness. It was possible to observe a high amount of Cd and Pb and a low amount of Ni and As in dental structure. The enamel surface and cross-section microhardness means of CS was statistically higher than the control group. The samples exposed to pH cycling (PC and CS-PC) showed lower surface microhardness means than the groups not exposed to the cycling (CS and Control), did not differ them. Study 2 evaluated the bond strength of composite resin restorations in teeth submitted or not to exposure to cigarette smoke. The bond strength was be evaluated in both enamel and dentin tissue. A total of 80 bovine dental fragments will be used. The fragments are divided into 8 groups (n=10), according to the type of adhesive (Scotchbond ¿ Multi-Purpose - 3M ESPE; Single Bond 2 - 3M ESPE; Clearfil SE Bond ¿ Kuraray; Single Bond Universal - 3M ESPE) and exposure to smoke (no exposure; exposure for 5 days, using 1 pack per day) previously to restoration with composite resin [Filtek Z250 (3M ESPE)]. After microshear enamel, it has been worn to exposed dentin and the restorative procedure was repeated. Data were statistically analyzed using ANOVA and Tukey test (p <0.05). For enamel, there was no difference in relation to exposure or not to cigarette smoke (p=0.1397), however, there were differences among the adhesive systems (p<0.001). CSEB showed higher values and did not differ from SBU, but both were statistically different from SB. The SBMP showed intermediate values while SB demonstrated lower values. For dentin, specimens subjected to cigarette smoke obtained bond strength values smaller to those not exposed to smoke (p<0.001). For the groups without exposure to cigarett smoke, CSEB showed higher values, differing from SBMP (lower values). SB and SBU showed intermediary values. For the groups with exposure to cigarett, SBU showed higher values differing from adhesives SB and CSEB that showed the lower. The adhesive SBMP showed intermediate value. It is possible to conclude that the exposure to cigarette smoke promoted heavy metal contamination both in surface and in depth, the smoke exposure increased the enamel microhardness without promoting an effect on the development of caries in vitro and the exposure of the tooth structure to cigarette smoke influence on the bonding strength of some adhesive on dentin, but not in enamel (AU)

• FAPESP's process: 13/15225-8 - Evaluation of the effect of cigarette smoke on the physical and chemical properties of the enamel and dentin and bond strength to resin composite using different adhesive systems
• Grantee: Jessica Dias Theobaldo
• Support Opportunities: Scholarships in Brazil - Master