Search results for "Orthodontics."
showing 10 items of 920 documents
Assessment of the stresses produced on the bone implant/tissue interface to the different insertion angulations of the implant - a three-dimensional …
2020
Background The present study aimed to assess the stresses produced on the surface of the bone tissue around dental implants with three different insertion angulations subjected to axial and oblique loading. Material and methods The study was created according to the recommendations of the Checklist for Reporting In-vitro Studies (CRIS). The Straumann™ bone level RC (4.1 x 10 mm) implant, Cone Morse connection (CM), RC Straumann Variobase™ with abutment (3.5 mm) was placed in the region of element 16, with the platform positioned at the height of the bone crest. Three assessment models were produced: model M1 or control - implant perpendicular to the bone crest; model M2 - implant angulated …
In vitro evaluation of shear bond strength of orthodontic stainless steel brackets using transillumination
2018
Background The objective of this study was to compare the effect of transillumination techniques to conventional light curing on shear bond strength (SBS) and adhesive remnant index (ARI) of orthodontic stainless steel brackets. Material and Methods 240 extracted human maxillary incisors, canines and premolars were randomly separated into four control and four experimental groups, based on tooth type. Labio-lingual thickness was measured. Control groups were light cured from buccal surface and experimental groups from lingual surface (transillumination) from four directions (mesial-distal, incisal-direct, direct, mesial-distal-incisal). SBS was measured using an Instron machine and ARI eval…
Shear bond strength of a flash-free orthodontic adhesive system after thermal aging procedure.
2019
Background The aim of this study was to compare the shear bond strength (SBS) of a flash-free and precoated orthodontic adhesive with a compomer orthodontic adhesive before and after thermocycling. The adhesive remnant index (ARI) was also determined for both adhesives. Material and Methods The adhesive remnant index (ARI) was also determined for both adhesives. Material and Methods: A total of 120 human premolars were randomly divided into two groups (n=60) according to the orthodontic adhesive used: APC Flash-Free Adhesive Coated Appliance System (APC FF) or Transbond PLUS Color Change Adhesive (TP), as control. A SBS test was performed and ARI value for each specimen was also assessed. R…
Micro-computed tomographic evaluation of dentinal defects after root canal preparation with hyflex edm and vortex blue rotary systems
2018
Background To evaluate the incidence of dentinal microcracks formation after root canal shaping procedures with HyFlex EDM and Vortex Blue rotary systems comparing with that of hand instrumentation using micro-computed tomography. Material and methods Mandibular first molar teeth (n=60) having 50 to 200mesial root curvature were scanned using high resolution micro-CT imaging before root canal preparation to identify the presence of dentinal defects. Post-instrumentation cross-sectional images were taken and increased number and type of root defects were assessed and recorded. The data was statistically analysed by using chi-square test and McNemar's test at a significance level of 5%. Resul…
Effect of over-the-counter whitening strips and toothpaste on shear bond strength of orthodontic brackets
2021
Background To investigate: 1) the effects of over-the-counter white strip enamel bleaching and 2-Step whitening toothpaste application on the shear bond strength of orthodontic brackets at 24-hours and 7-days post-bleaching latent period; and 2) the correlation between amount of bleaching and shear bond strength. Material and Methods Sixty human premolar teeth were randomly assigned into two bleaching groups, white strip group treated with Crest® 3D WHITE™ LUXE Professional Effects Whitestrips (Proctor & Gamble, Greensboro, NC), and whitening toothpaste group, treated with Crest® 3D WHITE™ BRILLIANCE 2-Step Toothpaste (Proctor & Gamble, Greensboro, NC). The groups were further divided into …
Radiographic Investigation of Frequency and Location of Root Canal Curvatures in Human Mandibular Anterior Incisors In Vitro
2007
The aim of the present in vitro study was to evaluate the degree and location of root canal curvatures of mandibular anterior incisors. A total of 396 extracted human permanent anterior incisors (248 central and 148 lateral) were included in this investigation. Exclusion criteria were teeth with extensive carious lesions, restorations, and root canal treatment. The specimens were fixed in a special device and digitally x-rayed (Heliodent MD; Sirona, Benzheim, Germany; Merlin 2.1, Olympus/PerkinElmer, Waltham, MA) with the parallel technique. The distances from the cementoenamel junction (CEJ) to the first curvatures as well as the according angles were recorded. The results were analyzed de…
In-vitro fatigue and fracture performance of three different ferrulized implant connections used in fixed prosthesis
2021
Background/purpose: The aim of the present in vitro study was to evaluate fatigue resistance of dental fixtures in three different types of fixture/abutment finishing line. Materials and methods: Transmucosal dental implants, with or without ferrulized neck, underwent fatigue tests (static and dynamic load) using the following standard protocol: UNI EN ISO 14801:2016. Two types of loading devices (screw- or cement-retained restoration) were also tested, and fatigue cycle tests were run to failure. Data of static and dynamic load tests were analyzed by proper statistical methods. Results: Following standard protocol for fatigue testing, the ILC type (Implant Level with ferrulized neck and ce…
Biomechanical Study of the Osteoporotic Spine Fracture: Optical Approach
2021
Background and objectives: Osteoporotic spine fractures represent a significant factor for decreasing quality of life in the elderly female population. Understanding the mechanisms involved in producing these fractures can improve their prevention and treatment. This study presents a biomechanical method to produce a vertebral fracture, conducted on a human spine segment, observing the displacements and strains in the intervertebral disc, endplate, and vertebral body. Materials and Methods: We performed two tests, one corresponding to an extension loading, and the second to an axial loading. Results: The maximum displacement in the target vertebral body presented higher values in the case o…
Treatment of Class III malocclusion using Hybrid Hyrax, Face Mask and Alt-RAMEC Protocol : a case report in a latin-american patient
2019
The management of Class III malocclusion is one of the greatest challenges of orthodontics. Current treatments offer the possibility of using direct skeletal anchorage to improve clinical outcomes. This case shows the results of using a Hyrax hybrid palatal anchorage, Alt-RAMEC (Alternate Rapid Maxillary Expansion and Contraction protocol) and a facemask to treat a maxillary hypoplasia Class III malocclusion in a Latin-American patient. The appliance design and the protocol used are widely described. Clinical and cephalometric results suggest that it is a good treatment option for this Latino patient, with moderate malocclusion and limitations in the dental anchorage. Key words:ALT-RAMEC, A…
Esthetic Assessment of the Effect of Gingival Exposure in the Smile of Patients with Unilateral and Bilateral Maxillary Incisor Agenesis
2014
Purpose: The aim of this study was to determine the dental esthetic perception of the smile of patients with maxillary lateral incisor agenesis (MLIA); the perceptions were examined pre- and post-treatment. Esthetic determinations were made with regard to the gingival exposure in the patients’ smile by orthodontists, general dentists, and laypersons. Materials and Methods: Three hundred eighty one people (80 orthodontists, 181 general dentists, 120 laypersons) rated the attractiveness of the smile in four cases before and after treatment, comprising two cases with unilateral MLIA and contralateral microdontia and two with bilateral MLIA. For each case, the buccal photograph was adjusted usi…