Effect of Remineralisation with Nano-hydroxyapatite (nHAp) and Non-collagenous Protein Analogues (PAA and STPP) on the Micro Tensile Bond Strength of the Resin Composites to Dentin – An In vitro Study
Soumya Nair
Department of Conservative Dentistry and Endodontics, Sri Rajiv Gandhi Dental College, India.
Sylvia Mathew
RUAS, Department of Conservative Dentistry, India.
John V. George
RUAS, Department of Conservative Dentistry, India.
Rhea Mathew *
Department of Conservative Dentistry and Endodontics, Sri Rajiv Gandhi Dental College, India.
Arathi S. Nair *
Department of Conservative Dentistry and Endodontics, Sri Rajiv Gandhi Dental College, India.
Chutty Issac
Department of Conservative Dentistry and Endodontics, Sri Rajiv Gandhi Dental College, India.
*Author to whom correspondence should be addressed.
Abstract
Background: Resin-dentin bonds are less durable than enamel as they rely on organic part for mineralisation. Bond denaturation mainly takes place because of hydrolysis of polymerized resin or degradation of water-rich, resin-sparse collagen by collagenolytic endogenous matrix metalloproteinase and cysteine cathepsins. Hence, this limited stability of dentin bonding tenaciously reduces the longevity of tooth-coloured restorations. One of the strategies adopted to encounter this shortcoming is to induce biomimetic remineralisation.
Aim: To assess the microtensile bond strength of resin composites to dentin following remineralisation using an experimental paste containing nano-hydroxyapatite (nHAp) and biomimetic analogues, Poly Acrylic Acid (PAA) and Sodium Tri Polyphosphate (STPP).
Methodology: Nine intact freshly extracted third molar were used for this study to evaluate the microtensile bond strength after treating with three different groups; Group I with paste containing nano hydroxyapatite nHAp Group II paste containing nHAp and non-collagenous protein analogues such as (Polyacrcrylic acid and Sodium tripolyphosphate) and the control groups containing adhesive and resin composite with no additional treatment. The samples were observed over a period of 24 hours and 1 week the inter group data analysis was done using ANOVA and paired sample t test and the intra-group data analysis over period of 24 hours the post HOC Bonferroni test was used for the statistical analysis.
Results: After 24 hours the group with nHAp group showed highest value for microtensile bond strength among other groups, however after one week the group with nHAp +NCP analogues(PAA+STPP) showed highest value for microtensile bond.
Conclusion: The treatment with the experimental paste [nHAp+NCP] analogues (PAA+STPP)] can bring about remineralisation to improve bonding to dentin.
Keywords: Microtensile bond strength, Nanohydroxy apatite, Poly Acrylic Acid (PAA), Sodium Tri polyphosphate (STPP)