Effect of mechanical and chemical surface treatment on bond strength of acrylic denture teeth to heat cure acrylic resin-an invitro study

Debonding of denture teeth from the denture base has posed a great problem to the clinician and patient. Chemical and mechanical treatments have been performed separately, but there are no studies performed using the combination of chemical and mechanical surface treatments. This study aims at evaluating and comparing the bond strength by using chemical and mechanical surface treatments.60 maxillary right central incisor teeth were used in 5 groups for surface treatment on the ridge lap area: 1 untreated, 2-sandblasting, group 3- Heat cure monomer, 4- sandblasting+ monomer, 5- Dichloromethane. The acrylic teeth were attached to a wax block at an angle of 45º. These were flasked and dewaxed, followed by surface treatment and acrylisation. All cured specimens were loaded under a universal testing machine on the palatal surface at a cross head speed of 1mm/min till fracture occurred. Data obtained was statistically evaluated by one way ANOVA. Surface treatment with dichloromethane showed the highest bond strength of acrylic teeth to heat cure denture base when compared with sandblasting and monomer application. On visual analysis of the fractured specimens, maximum amount of cohesive failures were noticed in the dichloromethane group.Dicholoromethane can be used as an effective and quick method to improve the bonding of acrylic teeth to denture base.