Comparative Study In Desensitizing Efficacy Of Dentin Desensitizers/Adhesives

OBJECTIVE: The purpose of this study was to evaluate the efficacy of two dentin adhesives, three dentin desensitizers and placebo.METHODS: A clinical investigation on the efficacy of dentin hypersensitivity (DH) treatment was carried out in the department of Stomatology, No.1 Hospital Affiliated to Medical College, Zhejiang University, Hangzhou, China from Feb. 2008 to Sept. 2008.Thirty-two volunteers (23 females and 9 males) with 64 sensitive teeth were recruited in the clinical study. The volunteers' ages arrange from 18 to 78 years, with the mean age of 42.8 years. The volunteers participated in this study after informed written consent. Two single-bottle self-etching adhesives (iBond, Heraeus; Xeno V,,Dentsply), three dentin desensitizers (Gluma desensitizer, Heraeus; Bifluorid 12, VOCO; Green Or, Italmed / Famaka) and a placebo (deionized water) were used in this study. A treatment for a hypersensitive tooth was randomly selected.To assess response to the mechanical stimulation, the sensitive area of the tooth was tenderly scratched with a new standard dental explorer. To assess response to thermal stimulation, the sensitive tooth was isolated with cotton rolls, and zero degree water (a mixture of ice and water) was dropped onto the tooth sensitive area. All volunteers were on fasting for 2 h after treatment, and instructed to eat and drink as usual during the clinical investigation period. The discomfort interval scale (DIS) ranging from 0 to 4 was used to test the level of hypersensitivity before and after treatment, and one month after treatment. All data were analyzed using the SPSS software package (version 16.0, SPSS Inc, Chicago, IL, USA).Impressions were taken from the sensitive teeth with an extremely low-viscous hydrophilic vinyl polysiloxane (Imprint^TM II Garant^TM 3M ESPE) plus putty rubber (Express? STD, 3M ESPE) using a two-step impression method at three different investigation times (before treatment, immediately after treatment and one month after treatment). Afterwards, replica models were made with epoxy resin (Struers) for the evaluation of the dentin surfaces by SEM (Scanning Electrical Microscopy). Epoxy resin replicas were gold-sputtered, and the some locations of interest on the replicas were analyzed with SEM.RESULTS: All the materials/treatments significantly reduced the tooth sensitivity immediately after treatment (P<0.05), when tested by the mechanical or thermal stimulus. All the materials with exception of the placebo could significantly relieve the thermal sensitivity of the teeth over one month after treatment (P <0.05). All the dental materials with exception of Bifluorid 12 and placebo could also significantly decrease the tooth mechanical sensitivity for one month after treatment (P<0.05). The placebo (water) significantly relieved the tooth mechanical/thermal sensitivity immediately after treatment (P<0.05), but it could not maintain its effect for a month (P >0.05).CONCLUSION: The single-bottle self-etching adhesives and dentin desensitizers involved in the present clinical investigation could significantly relieve the dentin hypersensitivity immediately and one month after the treatment. The fluoride containing varnish Bifluorid 12 could reduce the thermal/mechanical sensitivity of the dentin immediately, and the thermal sensitivity over a month, but failed in relieving the mechanical sensitivity over a month. Placebo (water) had an immediate effect on the dentin hypersensitivity. However, this effect did not last for one month.