Effect of Saliva and Desensitizing agent on the Shear Bond Strength of Metal and Ceramic Brackets using Self Etching Primer (an in Vitro Study) Mathur Ayush1,*, Naik CR2, Rahalkar Jayesh3, Deshmukh Sonali3, Jethe Sandeep4, Agarwal Vijay5 1Senior lecturer, NIMS Dental College, Jaipur, 2Head of Department, Dr. D.Y. Patil Dental College and Hospital, Pimpre, Pune 3Professor, Dr. D.Y. Patil Dental College and Hospital, Pimpre, Pune 4Reader, Dr. D.Y. Patil Dental College and Hospital, Pimpre, Pune 5Reader, Department of Orthodontics and Dentofacial Orthopaedics, NIMS Dental College, Jaipur *Corresponding author: Dr. Ayush Mathur, B.D.S, M.D.S., Senior lecturer, Department of Orthodontics, NIMS Dental College, Jaipur, India. F-48, Sunder Marg, C-scheme, Jaipur-302001(Rajasthan), Mob No: 9182909-16808, E-mail: drayushmathur@gmail.com
Online published on 10 February, 2015. Abstract Introduction Bonding procedure is routinely affected by contamination by saliva and desensitizing agents thereby affecting the strength of the brackets. The purpose of the study was to evaluate and compare the shear bond strength (SBS) of brackets under the influence of artificial saliva and desensitizing agent using self - etching primer (SEP). Materials and Methods 120 extracted sound human premolars were used. The teeth were divided into 6 groups of 20 each. Group 1- Control group (Metal and Ceramic brackets). Group 2- Saliva Contamination (Metal and Ceramic brackets). Group 3- Desensitizing Agent (Metal and Ceramic brackets). After bonding, all the specimens were subjected to thermocycling between two water baths containing distilled water at 55°C and 5°C for 500 cycles using a dwell time of 30 seconds. Each acrylic block with tooth mounted was placed into the universal testing machine. The shear load was applied to the bracket at a crosshead speed of 3mm/min. Post debonding, they were individually inspected under a stereomicroscope and scored according to the modified Adhesive Remnant Index (ARI). Results and Conclusion All groups displayed clinically acceptable mean bond strengths (over 8 MPa) even after the usage of artificial saliva and desensitizing agent making the use of SEP clinically acceptable. Ceramic brackets in all conditions displayed more shear bond strength than metal brackets. There is statistically significant decrease in the SBS of desensitizing agent groups when compared with control group of metal brackets and in the SBS of salivary contamination and desensitizing agent groups when compared with the control group of ceramic brackets. The use of desensitizing agent should thus be discontinued prior to bonding procedure. Modified ARI scores for metal brackets indicated that bond failure occurred at the bracket-adhesive interface or within the adhesive which is more desirable and safer than failure at the adhesive-enamel interface. For the ceramic brackets the bond failure mostly occurred at the adhesive enamel surface which is undesirable as it may lead to enamel fracture and crazing. Debonding for ceramic brackets should thus be done carefully. Top Keywords Shear bond strength, Self etching primer, Artificial saliva, Desensitizing agent, Modified Adhesive Remnant Index. Top |