RESUMO
BACKGROUND: Patients seeking orthodontic treatment are increasing, and clinicians often have to place brackets on various surfaces aside from enamel. It is crucial to know what materials or instruments are required to bond brackets to each surface. OBJECTIVE: This study aims to serve as a clinical guideline for the safest and most effective approaches taken to condition various surfaces for bonding to orthodontic brackets and provide background knowledge on the subject. MATERIALS AND METHODS: PubMed and EBSCO databases were searched, along with the use of Google Scholar search engine, to obtain relevant articles published in English in peer-reviewed journals, from 1955 to 2020. Keywords used were Shear bond strength; Orthodontic bracket; Base design; Etching; Sandblasting; Laser; Conditioning; Enamel; Ceramic; Porcelain; Gold; Amalgam; Composite. CONCLUSION: Even though orthophosphoric acid is the most widely used enamel conditioning agent, laser etching should be considered to avoid enamel decalcification. Hydrofluoric acid is the current standard for ceramic conditioning; however, its use intraorally should be minimized due to its toxicity. Orthophosphoric acid, CoJet-Sand air abrasion, and laser etching are viable alternatives for conditioning ceramic. Monobond Etch & Prime is toxic and should not be used intraorally. Composite can be conditioned by bur roughening, and the use of ceramic brackets is recommended. Amalgam and gold surfaces can be conditioned adequately by air abrasion. Despite the claims of many authors, the maximum shear forces that orthodontic brackets are subjected to are not 6-8 mega pascal (MPa). Further investigation is required in that regard. More in vivo studies need to be performed to confirm the in vitro results.
RESUMO
The aim of this study is to determine the dental arch dimensions (width and length) and form in a group of a Sudanese sample population. BACKGROUND: The size and shape of dental arches have significant implication in orthodontic diagnosis and treatment planning as it affects the space available, dental esthetics and stability of the occlusion. MATERIALS AND METHODS: This study is a biometric analysis of dental casts of 50 adult Sudanese dental students (20 males, 30 females) aged between 19 to 22 years with normal occlusion. The study was conducted at the orthodontic clinics, Faculty of Dentistry, University of Khartoum. Each student was interviewed and written consent was given. The inclusion criteria were: complete permanent dentition fully erupted to the occlusal plane, no proximal caries or restorations, no attrition or dental anomalies, no extractions, no previous or ongoing orthodontic treatment and no fractures or jaw surgeries. Paired-test, ANOVA test, and Pearson's correlation were used for statistical analysis with a p-value set at 0.05. RESULTS: The result showed normal occlusion is higher in males than in females. Upper arch dimensions (width and length) found to be higher in males than females, inter canine width (ICW), males 36, and females 34.45; interpremolar width (IPmW) males 48.08, females 47.58; inter-molar width (IMW) males 53.04, females 52.4; the length for males 37.98 and for females was 37.09. Comparison of Lower arch dimensions between males and females showed ICW (27.08 and 26.86); IPmW (40.97 and 39.67); IMW (45.61 and 45.69); depth was (33.91 and 33.91) consequently. The ovoid-shaped arch form was more common in both genders. CONCLUSION: Length dimension showed the highest value with square arch form. The width dimensions increase with little change in the inter-canine region but appreciably more in the distal part of the arch. Men have a more massive arch form than females. The ovoid arch form dominates in the Sudanese population. CLINICAL SIGNIFICANCE: Knowledge of arch dimensions that are associated with normal occlusion is helpful in determining treatment goals and proper diagnosis and treatment plan by choosing the right arch form for each race.
