ABSTRACT
The objective of this research was to fabricate a composite with an optimum filler level in a bisphenol-A-glycidyldimethacrylate (Bis-GMA) triethylene glycidal dimethacrylate (TEGDMA) resin for bonding of metallic orthodontic brackets to achieve the best handling characteristics with optimum bond strength and without compromising the mechanical properties of the adhesive. One-hundred and sixty extracted human premolars free of any detectable pathology or buccal surface alterations were collected and divided into four groups. In group 1 (control), the teeth were bonded with stainless steel brackets using Transbond XT. In groups 2, 3, and 4, the teeth were bonded with metal brackets using a Bis-GMA/TEGDMA resin with 80, 60, and 20 per cent by weight silane-coated silica of a spherical shape with a mean size of 0.01 µm. Shear bond strength (SBS) of the composites was determined and the adhesive remnant index (ARI) and enamel fracture post-debonding were assessed. According to one-way analysis of variance and Tukey's honestly significant difference (HSD) multiple comparison tests, the SBS of group 4 (10.54 MPa) was considerably less than that of groups 1 (26.1 MPa), 2 (25.5 MPa), and 3 (24.6 MPa). Chi-square analysis revealed that there was an insignificant difference in the incidence of enamel fracture between groups 1 and 2, while a significant difference was present between groups 1 and 2 and 3 and 4. An insignificant difference was also observed in the location of the adhesive failure between the four groups. While all the bonding adhesives tested can be safely used for bonding of brackets, 60 per cent filled Bis-GMA/TEGDMA was superior clinically due to its ease of handling and superior bond strength.
Subject(s)
Bisphenol A-Glycidyl Methacrylate/chemical synthesis , Composite Resins/chemical synthesis , Polyethylene Glycols/chemical synthesis , Polymethacrylic Acids/chemical synthesis , Resin Cements/chemical synthesis , Silanes/chemistry , Silicon Dioxide/chemistry , Acid Etching, Dental/methods , Acrylates/chemistry , Bisphenol A-Glycidyl Methacrylate/chemistry , Composite Resins/chemistry , Dental Bonding , Dental Debonding/adverse effects , Dental Enamel/injuries , Humans , Materials Testing , Orthodontic Brackets , Particle Size , Phosphoric Acids/chemistry , Polyethylene Glycols/chemistry , Polymethacrylic Acids/chemistry , Resin Cements/chemistry , Shear Strength , Stainless Steel/chemistry , Stress, Mechanical , Surface Properties , Tooth Fractures/etiologyABSTRACT
UNLABELLED: The purpose of this article was to analyze the various factors responsible for iatrogenic damage to a patient in an orthodontic practice and to advise precautions to prevent such damage. METHODS: All case reports describing iatrogenic damage published in all orthodontic journals indexed on PubMed and the related articles of all these case reports published in any journal. CONCLUSIONS: Good preventive practices can reduce and even completely eliminate the damage produced by the orthodontic operator.
