Clinical Evaluation of the Retention of Fissure Sealants Applied Following Guided Biofilm Therapy and Conventional Polishing

Pit and fissure sealants are used to prevent occlusal caries in permanent molars. Their clinical effectiveness depends largely on adequate penetration, marginal integrity, and long-term retention. Removal of plaque, pellicle, and debris from deep occlusal fissures before sealant application may therefore influence treatment success.

Conventional prophylaxis with a rotary brush is routinely used to clean the occlusal surface before acid etching. Guided Biofilm Therapy uses an air-polishing device with low-abrasive erythritol powder to remove biofilm. Due to its small particle size and low abrasiveness, erythritol-based air polishing may provide effective cleaning of occlusal fissures while minimizing damage to dental tissues. However, evidence regarding its effect on the long-term retention of pit and fissure sealants in children remains limited.

Systemically healthy children aged 6-10 years attending the Department of Pediatric Dentistry at Marmara University Faculty of Dentistry for routine dental treatment will be screened. Participants must have at least two comparable permanent first molars suitable for sealant placement. Teeth with previous restorations or sealants, advanced caries, molar-incisor hypomineralization, or other structural defects will be excluded. Approximately 80 children, corresponding to 160 permanent first molars, are planned to be enrolled.

A randomized split-mouth design will be used. For each participant, the right or left side will be allocated to one of the two surface-cleaning protocols by random selection, and the opposite side will receive the alternative protocol. Because both interventions are applied within the same participant, individual factors that may affect sealant retention can be controlled.

For teeth allocated to the Guided Biofilm Therapy protocol, the occlusal surface will be cleaned using an air-polishing device and an ultra-fine powder containing approximately 99% erythritol with a particle size of approximately 14 µm. The powder will be applied for 5 seconds from a distance of approximately 2 mm under suction.

For teeth allocated to the conventional protocol, the occlusal surface will be cleaned using a rotary prophylaxis brush. After the assigned cleaning procedure, all teeth will be etched with 37% phosphoric acid for 15 seconds. The surfaces will then be rinsed and dried, and a resin-based, fluoride-releasing pit and fissure sealant will be applied and light-cured for 15 seconds.

All interventions will be performed by the same trained clinician in accordance with the manufacturers' instructions. The procedures assigned to the two sides will be performed at separate appointments, with an interval of at least one week.

Participant age and sex will be recorded at baseline. Dental caries experience will be assessed using the dmft/DMFT index as part of the routine oral examination. Immediately after each procedure, the child's perceived pain or discomfort will be recorded using the Wong-Baker Faces Pain Rating Scale.

Clinical examinations will be conducted at 3, 6, 12, 24, and 36 months by an evaluator who is blinded to the surface-cleaning method used for each tooth. Sealant retention will be assessed using the modified Simonsen criteria and the Tonn and Ryge criteria. Additional clinical characteristics, including marginal adaptation, secondary caries, anatomical form, surface roughness, marginal discoloration, color match, and postoperative sensitivity, will be assessed using modified United States Public Health Service criteria.

When partial or complete sealant loss is detected, the sealant will be replaced according to routine clinical practice to prevent the tooth from remaining unprotected. The affected tooth and participant will then be considered to have reached the study endpoint and will be withdrawn from further study follow-up.