Search results for "Stomatognathic System"
showing 10 items of 1429 documents
In vitro evaluation of composite resin fluorescence after natural aging
2020
Background Some composite resins contain luminophorous agents in order to reproduce tooth fluorescence. The objective of this study was to compare the fluorescence spectra emitted by composite resins with those of human enamel and dentin, and their emission behaviour after a 90-day natural aging period. Material and Methods Nine shades of the composite resins Z350XT/3M (XT), Opallis/FGM (OP) and Empress Direct/Ivoclar-Vivadent (ED) were analyzed. Five specimens (10.0 mm x 2.0mm) were fabricated for each shade. Enamel (5.0 mm x 0.30 mm) and dentin (5.0 mm x 1.0 mm) specimens were obtained from sound human third molars. Fluorescence spectra of human dentin and enamel as well as the composite …
Comparative evaluation of shear bond strength of universal dental adhesives : an in vitro study
2017
Background Patient demand for tooth colored restorations and desire for minimally invasive restorations have made composites an indispensable part of the restorative process. An important factor affecting the intra-oral performance of composite restorations is bonding. Material and methods Ninty six freshly extracted molar teeth were collected and occlusal 3mm is removed using a diamond disc to expose dentine. Following with samples were divided in to two main groups (self-etch & total etch). Each main group is again sub divided in to three groups each according to bonding agent used (Tetric N- Bond Universal, Single Bond Universal, Tetric N Bond Total etch in total etch group and Clear Fil…
Danger zone analysis using cone beam computed tomography after apical enlargement with K3 and K3XF in a manikin model
2015
Background The objective of the study was to evaluate and compare how apical enlargement with K3 and K3XF nickel-titanium (NiTi) rotary instruments reduces the root thickness in the danger zone and affects canal transportation and centering ability in mandibular molar mesial canals in a manikin extracted tooth model. Material and Methods Seventy-two mesial root canals of first mandibular molars were instrumented. Initial and post-instrumentation Cone Beam Computed Tomography scans were performed after root canal preparation up to size 25, 30, 35 and 40 files. Canal transportation, canal centering and remaining root dentin thickness toward the danger zone were calculated in sections 1, 2 and…
Dental pulp calcifications in prehistoric and historical skeletal remains
2020
Abstract Background The prevalence of hard tissue formations in the dental pulp varies considerably. Beside ageing processes and irritations of the dental pulp, etiological associations with cardiovascular disease and dietary habits have been discussed, which are of particular research interest. The aim of this pilot study is to provide new insights on structural and etiological factors involved in the development of pulp calcifications by investigating skeletal remains from different (pre)historic periods. Methods The jaws of 46 skeletons excavated in central Germany, were examined for the presence of pulp stones using digital volume tomography (DVT). A total of 1122 teeth were examined wi…
Interradicular Root Canals in Mandibular First Molars: A Literature Review and Ex Vivo Study
2019
Abstract Introduction Successful endodontic treatment vastly depends to a high degree on an accurate knowledge of root canal system morphology. It is a prerequisite to be aware of all possible reservoirs where bacteria and/or toxins can persist, compromising the surrounding tissues; such knowledge results in endodontic success. Methods The presence of interradicular canals and diverticula between the pulp chamber floor and the bifurcation area surface of 117 mandibular first molars was investigated. Access cavities were prepared, the teeth were embedded in plastic, and the pulp chambers were flooded with methylene blue and then centrifuged. An average of 4.2 (0.145 ± 0.03 mm thickness) slic…
Three-dimensional analysis of the physiological foramen geometry of maxillary and mandibular molars by means of micro-CT.
2017
The aim of this study was to investigate the physiological foramen diameter, shape and distance between physiological and anatomical apex of maxillary and mandibular first and second molars. Accurate knowledge of the physiological foramina morphology; thus, inherent mechanical shaping technical hindrances, is decisive when taking the corresponding root canal final preparation decision. The morphological dimensions of a total of 1727 physiological foramina were investigated by means of micro-computed tomography. Mean narrow and wide (to a high number, oval) diameters of the physiological foramen were 0.24, 0.22 and 0.33 mm and 0.33, 0.31 and 0.42 mm in mesiobuccal (MB), distobuccal (DB) and …
Ultrasonic techniques to obtain dental pulp from impacted third molars.
2019
Background In the dental clinic impacted teeth are frequent findings, especially upper and lower third molars, leading to their exodontia. Among surgical techniques piezosurgery is advantageous for delicate structures in the oral cavity. Extracted teeth, usually discarded, have been revalued as biological material, providing living tissues with possible applications in regenerative dentistry. The aim was to compare cross-section methods of upper included third molars by ultrasonic piezoelectric technique to obtain dental pulp, with diamond-coated tip (DT) against titanium nitride-coated tip (TN), according to the pulp tissue cell viability and the section surface characteristics. Material a…
Cheek-splitting technique for marginal mandibulectomy: A novel approach
2019
When performing marginal mandibulectomy, ensuring complete tumor removal and preventing postoperative iatrogenic mandibular fracture are essential. Pathological fracture can result due to stress concentration at the site requiring acute angle resection. To perform marginal mandibulectomy without making acute angles in patients with a lesion in the molar or more posterior region, a submandibular or transbuccal approach is necessary. Compared to the submandibular approach, the transbuccal approach is considered useful as it reduces operative time and prevents injury to the facial and mental nerves. Additionally, this approach does not leave a scar in the surgical field, which is beneficial in…
Sensory disturbances of buccal and lingual nerve by muscle compression: a case report and review of the literature
2016
Introduction Several studies on cadavers dissection have shown that collateral branches of the trigeminal nerve cross muscle bundles on their way, being a possible etiological factor of some nerve disturbances. Case Report A 45-year-old man attended to the Temporomandibular Joint and Orofacial Pain Unit of the Master of Oral Surgery and Implantology in Hospital Odontològic of Barcelona University, referring tingling in the left hemifacial región and ipsilateral lingual side for one year, with discomfort when shaving or skin compression. Discussion Several branches of the trigeminal nerve follow a path through the masticatory muscles, being the lingual nerve and buccal nerve the most involve…
Expansion of permanent first molars with rapid maxillary expansion appliance anchored on primary second molars
2018
Background To evaluate how the amount of expansion of the primary second molars, the patient's age, and the skeletal maturation stage influence the amount of expansion at the level of the permanent first molars. Material and methods Fifty-five patients aged between 6 and 11 years with a cervical vertebral maturation stage of CS1 or CS2 were retrospectively selected. The intermolar width was measured before and after expansion to evaluate the amount of expansion achieved at the level of the primary second molars and the permanent first molars. Stepwise multiple linear regression was used to evaluate how the amount of primary molars expansion, the patient's age, and the cervical vertebral mat…