The effect of salivary contamination on microleakage of composites bonded with current generation adhesives

The aim of this study was to evaluate the effect of salivary contamination on microleakage of composites bonded onto human teeth with current generation adhesives. One hundred and fifty human premolars free of caries, fluorosis and restoration were randomly assigned to 15 treatment groups of 10 teeth each. The treatment groups were defined by the combination of 5 bonding agents & 3 surface conditions. Class V cavities were prepared on the buccal surfaces of the teeth. They were acid etched with 37% phosphoric acid gel for 15 seconds, water rinsed for 30 seconds and air dried for 15 seconds. The first surface treatment was an ideal no saliva contaminated surface acting as a control group. The second surface treatment was saliva contamination left undisturbed for 15 seconds and blot dried with cotton pellets. This corresponds to contamination being unnoticed in the clinical situation. The third surface treatment was saliva contamination and water rinsed. This corresponds to contamination being noticed at the time of occurrence and washed as soon as possible. Then composite restorations were placed in two increments and light cured for 20 seconds for each increment. The teeth samples were thermocycled, coated with nail varnish and immersed in methylene blue dye for 48 hours. The teeth specimens were sectioned bucco-lingually and assessed for microleakage using a scoring criteria of 0-3 by viewing under stereomicroscope at 40X magnification. Then the results obtained were statistically analyzed firstly to compare the bonding efficiency of the five current generation adhesives, secondly their efficacy under different surface treatment conditions and thirdly an inter group comparison for each of the adhesives in different surface treatment condition was carried out. The conclusions that can be drawn from the present study are as follows: 1. Of the five current generation adhesives tested, the single bottle adhesives namely Adper, Gluma and Excite showed equally good performance with minimal microleakage scores compared to Syntac and Prompt L Pop. 2. Of the five current generation adhesives that were tested, the single bottle adhesives namely Adper, Gluma and Excite showed very good bonding efficiency and minimal microleakage with no statistically significant differences between each of them. 3. The Syntac and Prompt L Pop adhesives did not show good bonding efficiency when compared to the single bottle adhesives with the latter performing the worst. 4. With regard to salivary contamination samples, the three single bottle adhesives performed the best(Group 3, 6 and 9) followed by Syntac (Group 12). 5. The bonding efficiency of Prompt L Pop (Group 15) in the presence of salivary contamination was once again found to be poor. 6. An inter group comparison of the performance of the five different adhesive systems in different surface treatment conditions(uncontaminated, saliva contamination and blot dried, saliva contamination and water rinsed) revealed that the single bottle adhesives performed equally well followed by Syntac with Prompt L Pop faring the worst. While the outcome of the study clearly implies the superiority of the single bottle adhesive systems with regard to bonding efficiency and microleakage, further clinical research needs to be done on a large sample size