EVALUATION OF FOUR MATERIALS FOR A REVERSIBLE SEALING OF DENTAL SURFACES

Objectives: To assess qualitatively the efficiency of four materials tested for the reversible sealing of dental surfaces.
Methods: After a bibliographic review, four materials were chosen on grounds of their chemical composition and physical properties. Twenty selected human third molars were cut along the longitudinal and crown axes to get two half-crowns, from each tooth, then halves were stored in 4% W/W chloramine-T solution. The forty halves were randomly divided into four groups (n=10): G1 Dental rubber dam (Dental Dam®), G2 PTFE Teflon Topex® tape, G3 Vinilpel® polyvinyl chloride film, G4 polyvinyl chloride electrical tape by Tesa® . Each occlusal and cervical surface was coated with Utility® wax. The freshly exposed surface was sealed with the material chosen for each group using a new method “sandwhich” as follows: Two square floated glass slabs 2cm X 2cm, 3 mm thickness wrapped in one of the four materials were placed under and on top of the tooth halves and held together with rubber bands and then were immersed in an aqueous 2% W/W methylene blue (MB) solution for six days, then were briefly rinsed and paper tissue dried. The MB penetration was assessed by direct observation on the exposed surfaces. A binomial (yes or no) response was assigned and a percentage of leaking or sealing was computed.
Results: G1 Seven out of ten specimens (70%) showed MB intrusion, G2 showed no leaking (0%), G3 rendered 100% leaking and G4 90% leaking.
Conclusions: Teflon is the best tested material for reversible sealing against leaking of solutions of the molecular size and characteristics of MB without leaving any trace of adhesives, plastics additives, ions, etc and is therefore fit for in vitro studies.