KOMPLİKE OLMAYAN KRON KIRIKLARININ TEDAVİSİNDE İNSİZAL FRAGMANIN REATAÇMANINDA KULLANILAN UNİVERSAL ADEZİVLERİN FARKLI UYGULAMA TEKNİKLERİNİN VE PH’LARININ KIRILMA DAYANIMI ÜZERİNE ETKİSİNİN ARAŞTIRILMASI

Abstract

Bağdatlı, Z. The Effect of Different Application Techniques and pH Values of Universal Adhesives Used in the Reattachment of Incisal Fragment of Non-complicated Crown Fractures on Fracture Strength. Hacettepe University, Faculty of Dentistry, Department of Restorative Dentistry, Specialization Thesis, Ankara, 2024. The aim of this in vitro study was to investigate the effect of universal adhesives with different pH values, applied with selective etch or self-etch methods, on the fracture strength of reattached teeth due to enamel dentin fractures after dental trauma. Seventy caries-free bovine lower incisors were included for the test purposes. The teeth were embedded in silicone molds (15 mm x 20 mm) up to the cemento-enamel enamel junction. Ten teeth were randomly assigned as the control, 30 teeth assigned as self etch and 30 teeth assigned as selective etch groups. Then, each group were further divided into 3 subgroups (n=10) according to the pH of the adhesive as intermediately strong (G Premio Bond, GC, Tokyo, Japan), mild (Single Bond, 3M Espe, St. Paul, MN, USA.) and ultra mild (All Bond Universal, Bisco Inc., A.B.D.) adhesive groups. To obtain standardized fragments from the specimens in the test groups, the teeth were cut 5 mm away from the incisal edge using a precision cutting device (Microcut 201, Metkon, Bursa, Turkey) under water cooling. Then, the fragments were reattached after the application of the designated adhesion protocol as follows; Group I: control (C), Group II: Selective etch (SE) + G Premio Bond (GP), Group III: SE + Single Bond (SB), Group IV: SE + All Bond (AB), Group V: Self + GP, Group VI: Self + SE, Group VII: Self + AB. The samples were then subjected to 10000 cycles for aging (Thermocycler, SD Mechatronic, Germany). Fracture strength was tested by a universal testing device (Instron 4411, Canton, MA, USA). Subsequently, the fracture mode analysis were done under a stereomicroscope (Leica MZ12, Leica Microsystems Ltd, Almanya). The data were analyzed using the SPSS (Statistical Package for the Social Sciences) 23.0 package. The mean ± standard deviation was calculated for all measurements. Whether the data showed a normal distribution was tested using the Shapiro-Wilks test. The differences between groups in terms of fracture strength were determined using a one-way analysis of variance (ANOVA). Multiple comparisons were done using the LSD test. Dunnett's test was used in comparisons with the control. The statistical significance was determined as p = 0.05. A significant difference was found between the groups in terms of fracture strength (p = 0.016). The groups with the highest bond strength, respectively, were K > Self + GP > SE + AB > SE + SB > SE+ GP > Self + SB > Self + AB. When the selective etch-applied groups were compared among themselves, no significant difference was found (p = 0.972). When the self-etch applied groups were compared among themselves, a significant difference was found (p = 0.008). Regarding pH value, the application of adhesive with intermediately strong pH value by selfetch or selective etch technique did not make a difference in terms of fracture strenght (p = 0.692). However, a difference was found in the adhesives with mild and ultra mild pH vaue (p = 0.032, p = 0.014, respectively). In terms of fracture mode, adhesive failure was most common, but there was no significant difference among the groups (p = 0.133). Within the limitation of the current study, acid etching strategy and pH of the adhesive resin can effect the fracture strenght of reattached teeth