Untersuchung der mechanischen Beständigkeit von Glattflächenversieglern während der Multibracketbehandlung : eine in vitro Studie

Objectives: White spot lesions are a possible undesirable side effect of orthodontic treatment with fixed appliances. Smooth surface sealing is a clinical procedure independent of the patient's cooperation, which is intended to prevent demineralisation. The aim of this in vitro study was to examine five sealers for their thermomechanical wear resistance. Material and method: 125 human anterior and canine teeth were randomly divided into 6 testing groups: 20 teeth served as unsealed control group (group A). All other teeth were equally divided into group B: Pro Seal® (Reliance Orthodontics), C: Light BondTM (Reliance Orthodontics), D: ClearfilTM Protect Bond (Kuraray), E: Ortho SoloTM (Ormco) and Group F: Protecto® CaF2 Nano (BonaDent). One tooth sample of each of the groups B-F served as reference, that didn´t undergo any mechanical testing. The remaining samples were subjected to a simulated two-year wear and aging process consisting of artificial aging by thermocycling and light exposure, chewing simulation in a chewing simulator, tooth brushing simulation in a brushing robot, and powder water jet cleaning with calcium carbonate powder. The surface quality of the test samples was investigated quantitatively and qualitatively by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (SEM-EDX). Statistical evaluation was carried out using the Mann-Whitney U-test or Kruskal-Wallis test ( =0.05) Results: The samples sealed with Pro Seal® (group B) showed the highest mechanical wear resistance with the lowest substance loss of all groups. Significantly larger defects were already detected in the ClearfilTM Protect Bond group (group D). With all other smooth sealants, a near complete loss of the sealing was observed. Furthermore, no investigated smooth surface sealant was able to completely withstand the mechanical stress. Conclusion: Based on the observations of the present study, the application af a smooth surface sealant can be considered as one option of caries prophylaxis, which should not be used exclusively but always in combination with other methods. Further in vitro and in vivo studies are needed to investigate the mechanical wear resistance of the smooth surface sealants and to determine the indication area of smooth surface sealing in the context of orthodontic caries prophylaxis