Effect of CO2 laser, associated or not to fluoride, on root caries prevention - in vitro and in situ studies

• Grant number: 10/01863-4
• Support Opportunities: Regular Research Grants
• Start date: May 01, 2011
• End date: October 31, 2013
• Field of knowledge: Health Sciences - Dentistry
• Principal Investigator: Wanessa Christine de Souza Zaroni
• Grantee: Wanessa Christine de Souza Zaroni
• Host Institution: Centro de Ciências Biológicas e da Saúde. Universidade Cruzeiro do Sul (UNICSUL). São Paulo , SP, Brazil
• Associated researchers: Marines Nobre dos Santos Uchôa ; Michel Nicolau Youssef

Abstract

This research will be divided in four studies, two in vitro and two in situ. The first in vitro study will investigate the effect of CO2 laser, associated or not to the use of fluoride in the form of dentifrice, varnish or fluoride phosphate acidulated gel, on the inhibition of root surface demineralization. It will be employed 180 human dental root blocks which will be divided into 12 groups: 1. C- dentifrice without Fluoride (negative control); 2. DF - fluoride dentifrice; 3. L - 5.0 J/cm2 CO2 laser + non-fluoride dentifrice; 4. DF + L - 5.0 J/cm2 CO2 laser + fluoride dentifrice; 5. V - fluoride varnish; 6. V+DF - fluoride varnish + fluoride dentifrice; 7. V + L - 5.0 J/cm2 CO2 laser + fluoride varnish; 8. V+L+DF - 5.0 J/cm2 CO2 laser + fluoride varnish + fluoride dentifrice; 9. APF - fluoride phosphate acidulated; 10. APF+DF - fluoride phosphate acidulated + fluoride dentifrice; 11. FFA + L - 5.0 J/cm2 CO2 laser + fluoride phosphate acidulated; 12. FFA+L+DF - 5.0 J/cm2 CO2 laser + fluoride phosphate acidulated + fluoride dentifrice. The second in vitro study will investigate the effect of CO2 laser, associated or not to the use of fluoride in the form of dentifrice, on the inhibition of demineralization of root surface adjacent to composite resin or glass ionomer cement restorations. The cavities will be prepared with a diamond tip and divided into 2 groups according to the restorative material employed: composite resin (Z 250) or glass ionomer cement (Fuji IX). After this, the specimens will be divided into 4 subgroups according to cavo-surface angle treatment: 1. C- dentifrice without Fluoride (negative control); 2. DF - fluoride dentifrice; 3. L - 5.0 J/cm2 CO2 laser + non-fluoride dentifrice; 4. DF + L - 5.0 J/cm2 CO2 laser + fluoride dentifrice. Mineral loss of root surface and around restorations will be quantified by microhardness analysis. The in situ study has two objectives: the first is to investigate the effect of CO2 laser, associated or not to the use of fluoride in the form of dentifrice, on the inhibition of root demineralization (Study 1), and the second is to investigate the effect of CO2 laser, associated or not to the use of fluoride in the form of dentifrice, on the inhibition of demineralization of root surface adjacent to composite resin restoration (Study 2). It will be employed human dental root blocks which will be divided into 4 groups for each part: Study 1: 1. NF - root surface + non-fluoride dentifrice (control); 2. F - root surface + fluoride dentifrice; 3. NF+L - root surface + 5.0 J/cm2 CO2 laser + non-fluoride dentifrice; 4. F+L - root surface + 5.0 J/cm2 CO2 laser + fluoride dentifrice; Study 2: 1. P- cavity preparation with diamond tip + dentifrice without Fluoride (negative control); 2. PDF - cavity preparation with diamond tip + fluoride dentifrice; 3. P + L - cavity preparation with diamond tip + 5.0 J/cm2 CO2 laser + non-fluoride dentifrice; 4. PDF + L - cavity preparation with diamond tip + fluoride dentifrice. All the cavities will be restored with composite resin (Z 250) and adhesive system without fluoride (Singlebond). Each in situ part will be taken in two phases of 14 days each, with 14 volunteers. At the end of each phase, F, Ca, P, and alkali soluble polysaccharide levels will be evaluated on collected biofilm. Mineral loss of root surface (Study 1) and around restorations (Study 2) will be quantified by microhardness analysis. The results will be statistically analyzed through parametric tests. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

RODRIGUES, S. R.; MORAES, M.; HANASHIRO, F. S.; YOUSSEF, M. N.; BRUGNERA JUNIOR, A.; NOBRE-DOS-SANTOS, M.; DE SOUZA-ZARONI, W. C.. The effect of CO2 laser irradiation plus fluoride dentifrice on the inhibition of secondary caries on root surfaces adjacent to glass ionomer cement or composite resin restorations. Laser Physics, v. 26, n. 2, FEB 2016. (10/01863-4)