Search results for "Tooth"
showing 10 items of 910 documents
Methodology in specimen fabrication for in vitro dental studies: Standardization of extracted tooth preparation
2017
Background Specimen preparation for in vitro study suffers a general lack of methodological homogeneity, as well as a lack of uniformity in the materials selected for fabricating them. This situation prevents comparisons between studies. When a specimen is not of dental origin it is not possible to study adhesion or bonding techniques realistically. The objective is to design and implement a method of specimen preparation that permits universal standardization for use in in vitro studies. Material and Methods A metal stump of specified dimensions was designed and fabricated by hand. It was scanned, the data digitalized, perfecting and standardizing the dimensions. Ten human molars were adap…
Dental caries experience, tooth surface distribution and associated factors in 6- and 13- year- old school children from Davangere, India
2012
Objectives: The objective of the present study was to investigate the caries experience and patterns in a sample of 6- and 13- year old school children and to estimate the contributing roles of the likely risk indicators. Study design: Data were obtained from 400 (196, 6-year old and 204, 13-year old) school children. A questionnaire was sent to the children parents to measure socioeconomic, socio-demographic, and behavioral variables. Dental caries detection was performed according to the World Health Organization criteria (dmft and DMFT). The mean dmft/DMFT scores were analysed either as a continuous (calculating means and standard deviations) or as a categorical variable (providing propo…
Determination of the facial/oral alveolar crest using RF-echograms. An in vitro study on the periodontium of pigs.
1989
Abstract This study is a part of a research project in which we have been investigating the use of the ultrasonic pulse echo technique as a means of determining in vivo the facial/oral alveolar crest precisely and routinely. Here, RF-echograms are presented, showing the facial/oral periodontium of pigs. These echograms have been produced using a focussed 20 MHz transducer and a special design of an ultrasonic measuring and analysis system. In one series of measurements on macerated periodontia of pigs we found out that RF-echograms characteristic of a particular level of the facial/oral pericrestal aspect can be achieved. Based upon these results, we succeeded in determining exactly the hei…
Ultrasonic B-scans of the facial/oral periodontium in pigs.
1989
In vitro ultrasonic scans of the oral/facial periodontium of pigs were obtained using a special experimental design and with the help of a newly developed ultrasonic measuring and analysis system. These two-dimensional images distinguish themselves from the one-dimensional RF-echograms and A-scans in that they enable the viewer to have a quick overview of the relationship between different interfaces in a scanned sector. A selection of ultrasonic B-scans proves that the scanned tissues such as gingiva, bone, periodontal ligament, tooth surface and even structures of the inner part of the tooth may be clearly imaged and distinctly differentiated. Furthermore, we demonstrate with manipulation…
Reimplantation: clinical Implications and outcome of dry storage of avulsed teeth
2010
Reimplantation refers to the insertion and temporary fixation of completely or partially avulsed teeth that have resulted from traumatic injury. Reimplantation of an avulsed tooth depends on certain clinical conditions like phy- siological status of periodontal ligament (PDL), the stage of root development and the length of extra oral time. Depending on the patient’s age, retention of the permanent incisor can maintain the aesthetic appearance, occlusal function and alveolar ridge height. Though the risk of progressive replacement resorption and subsequent tooth loss is high after a long dry storage, reimplantation makes a provision for an aesthetically acceptable permanent prosthesis at a …
Double talon cusps on supernumerary tooth fused to maxillary central incisor: review of literature and report of case
2014
Human tooth development is a continuous process begin at the sixth weeks in utero and extends to about sixth months after birth for the primary dentition and from sixteenth week in utero to late adolescence for permanent dentition. There is no other organ of the human body which takes so long to attain its ultimate morphology as dentition. Several physiologic growth processes participate in the progressive development of the teeth including: initiation, proliferation, histodifferentiation, morphodifferentiation, apposition, calcification, and eruption. Aberrations in different stages of tooth development can result in unique manifestations both in primary and permanent dentitions. The fact …
Influence of tooth loss on mandibular morphology : a cone-beam computed tomography study
2019
Background Tooth loss adversely affects patients’ health and psychosocial wellbeing. In addition, it changes mandibular morphology. Objective: To evaluate the effect of tooth loss, age, and gender on mandibular morphology. Material and Methods Cone-beam computed tomographic (CBCT) scans of 101 patients were examined to measure the gonial angle (GA), ramus height (RH) and condylar height (CH). Patients’ age, gender, and dental status were recorded. Repeated measures analysis of variance (ANOVA) was used to assess the impact of gender, age, and tooth loss on the GA, RH and CH. The mean measurements of the GA, RH and CH were compared between dentate/edentulous patients after splitting by gende…
In vitro investigation of the impact of remaining tooth structure on the tensile failure loads of overdenture copings
2019
Background The purpose of this in vitro study was to evaluate the impact of the remaining tooth structure on the retention of overdenture cast metal copings. Material and Methods A freshly extracted intact mandibular human canine (length 25 mm) was selected and endodontically treated. An incisal reduction of 4 mm with no ferrule preparation was performed and a post space of 12 mm was created. By using polyvinyl siloxane duplication material and autopolymerizing polymethylmethacrylate resin, ten resin teeth analogs (control group) were obtained. A second set of ten resin teeth analogs (group 1) was created by preparing on the original natural tooth a 360o ferrule design of 1 mm in height and…
Rates of tooth movement and bone remodeling activity : self-ligating versus conventional brackets
2019
Background Bracket systems have been developed with the purpose of reducing frictional resistance between the archwire and accessories. The aim of this research was to compare rates of tooth movement and regions of cellular bone modeling activity along tooth root surfaces of teeth moved with conventional vs. self-ligating brackets. Material and Methods The experiments were conducted in 20 male dogs. Bands were cemented in all intermediate incisors, with conventional brackets (Morelli) on the right side and hybrid self-ligating ones (T3-American Orthodontics) on the left side. A 0.019” x 0.025” stainless steel wire was inserted passively in the slot of these brackets with chain elastics (250…
Accuracy of 4 digital scanning systems on prepared teeth digitally isolated from a complete dental arch
2018
Abstract Statement of problem The accuracy of digital scanners is acceptable for scanning a complete dental arch. However, whether that accuracy is sufficient for only 1 tooth within the dental scan of a complete dental arch is unclear. Purpose The purpose of this in vitro study was to evaluate and compare the accuracy of 4 intraoral scanners on a complete dental arch and on prepared teeth digitally isolated from the digital scan in terms of trueness and precision. Material and methods A model of a complete dental arch with tooth preparations was scanned 40 times with each of the 4 digital scanners. Their accuracy was evaluated by using 3-dimensional (3D) software to compare the test models…