Background and Objective Cold atmospheric plasma (CAP) has the potential to decontaminate and disinfect carious lesions without the need for mechanical preparation. This study aimed to evaluate the effect of CAP on the bonding strength of composite and porcelain to enamel in an in vitro setting.

Materials and Methods 44 sound premolar teeth extracted for orthodontic purposes were selected and randomly divided into two groups. The first group CAP treatment (CAP group), while the second group did not receive CAP treatment (NO CAP group). Each group was further subdivided into two subgroups: one prepared for bonding with E-max porcelain (E CAP and E NO CAP) and the other for bonding with composite resin (C CAP and C NO CAP).

In the composite subgroups, all samples were etched, rinsed and air-dried. They were then coated with a fifth-generation Kulzer bonding agent, light-cured, and subsequently bonded with composite disks (5 mm in diameter), which were light-cured again for 40 seconds.

In the E-max subgroups, the enamel surfaces were etched with HF acid, rinsed, and air-dried. They were then treated with Bisco silane, followed by application of the fifth-generation Kulzer bonding agent. The E-max disks (5 mm in diameter) were bonded using a self-adhesive dual-cure resin cement and cured for 2.5 minutes.

shear bond strength testing done using a Zwick/Rowell testing machine until debonding occurred. The failure mode (adhesive or cohesive) and debonding location were examined using a light microscope.

Results Following plasma treatment, the median bond strength in the composite group increased from 88.7 to 92.6 MPa, while in the ceramic group, it increased from 174.5 to 187.4 MPa. Additionally, in the composite group, the number of cohesive failures increased from 3 in the NO CAP subgroup to 9 in the CAP subgroup. Similarly, in the ceramic group, the number of cohesive failures increased from 1 to 3 after CAP treatment.

Conclusion the effect of CAP on increasing cohesive failures in ceramics was not significant, whereas in the composite group, this effect was statistically significant.

The authors have declared no competing interest.

this study did not receive any funding

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The details of the IRB/oversight body that provided approval or exemption for the research described are given below:

The protocol of the present research was approved by the university ethics committee with Ethical Approval Number IR.AJAUMS.REC.1403.141.

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