Search results for "cavity"

Microreflectivity studies of wavelength control in oxidised AlGaAs microcavity

2002

An anti-zipping preparation system (method and instrument) for curved root canals: A preliminary report

1996

A new instrument and method of preparation of curved canals, with which preparation effects such as "zips" and "elbowing" at the apical third can be easily eliminated, is described. The new system was designed to incorporate requirements previously established during clinical and laboratory experiments.

Influence of Operator's Experience on Root Canal Shaping Ability with a Rotary Nickel-Titanium Single-File Reciprocating Motion System

2013

The aim of this study was to evaluate the influence of the operator's experience on the shaping of double-curvature simulated root canals with a nickel-titanium single-file reciprocating motion system.Sixty double-curvature root canals simulated in methacrylate blocks were prepared by 10 students without any experience in endodontics and by 10 professionals who had studied endodontics at the postgraduate level. The Reciproc-VDW system's R25 file was used in the root canal preparation. The blocks were photographed before and after the instrumentation, and the time of instrumentation was also evaluated. Changes in root canal dimensions were analyzed in 6 positions.Significant differences (P.0…

Use of cone-beam computed tomography to evaluate root and canal morphology of mandibular first and second molars in Turkish individuals

2013

Objective: The aim of this study was to investigate the root and canal morphology of mandibular first and second molars in a Turkish population by using cone beam computed tomography (CBCT). Study design: CBCT images of mandibular first (n = 823) and second molar (n = 925) teeth from 605 Turkish patients were analyzed. The root canal configurations were classified according to the method of Vertucci. Results: The majority of mandibular molars (95.8% of first molars, 85.4% of second molars) had two separate roots; however, three roots were identified in 2.06% of first molars and 3.45% of second molars. C-shaped canals occurred 0.85% of first molars and 4.1% of second molars. Three canals wer…

Diversity of Lactobacillus species in deep carious lesions of primary molars

2010

AIM: This was to determine the prevalence of Lactobacilli (LB) species in different stages of caries progression and are considered as secondary invaders of existing carious lesions and specialists for caries progression. METHODS: Carious dentine samples were collected from 70 primary molars (M) during step-wise (S1, S2: n = 35 M) or one-step (O1: n = 35 M) caries treatment and after 11 months of temporary restorations (S3, O2). LB were identified by selected physiological and biochemical characteristics, ratio of lactic acid isomers, electrophoretic mobilities of lactic acid dehydrogenases, and shotgun mass mapping by MALDI mass spectrometry. RESULTS: LB were isolated from 46% of soft dent…

Evaluation of morphological changes produced by orifice opener systems using computerized tomography (CT)

2009

Objectives: To evaluate modifications in root canal morphology following instrumentation with orifice openers using Computerized Tomography (CT). Study design: Experimental in vitro study. A preoperative CT was performed on 49 molars to measure the root canal cross-sections. After preparing the canals with 6 different nickel-titanium (Ni-Ti) rotary system orifice opener type instruments and Gates Glidden burs, a further CT was made and compared with the preoperative one. Kruskal-Wallis and ANOVA statistical analysis were used. Results: Gates Glidden burs were significantly more aggressive in the coronal portion of the canals, although all the instruments removed more dental tissue in the mo…

Comparing the antibacterial activity of gaseous ozone and chlorhexidine solution on a tooth cavity model

2013

Objective: To evaluate the antibacterial activity of gaseous ozone andchlorhexidine solution on a tooth cavity model. Study Design: Twenty-one human molars were divided into 3 groups. Cavities were then cut into the teeth (4 per tooth, 28 cavities per group). After sterilization, the teeth wereleft in broth cultures of 106 colony-forming units (CFU) ml-1 of Streptococcus mutans (S. mutans) at 36°C for 48 h. The appropriate treatment followed (group A, control; group B, 2% chlorhexidine solution; and group C, 80s of treatment with ozone, and the cavities were thenfilled with compositeresin. After 72h, the restorations were removed, dentin chips were collected with an excavator, and the total…

Morphology of the Physiological Foramen: I. Maxillary and Mandibular Molars

2004

Information concerning the anatomy of the physiological foramen is limited. The aim of this study was to investigate the distance between the physiological and anatomical apex, accessory foramina frequency, and the shape and diameter of the physiological foramen in maxillary and mandibular molars. The apical anatomy of 523 maxillary and 574 mandibular molars from an Egyptian population was investigated by means of a computer-aided stereomicroscope (40 x magnification). The following results were obtained:

An in vivo comparative study of two apex locators

1994

Two different electronic apex locators were used before extraction to determine working length in 116 root canals belonging to 34 molars. The results were then compared with postextraction working length measurements. The determinations were made before and after eliminating the canal contents and drying the interior. The results showed that 84.8% and 79.3% of the Odometer, and 89.6% and 88.7% of the Endocater readings for dry and nondry canals, respectively, occurred within the two 0.5-mm intervals closest to the apical constriction.

Adverse Reactions to Anticancer Drugs in the Oral Cavity

2018

The development, testing, and adoption into clinical practice of anticancer medications have revolutionized cancer care over the past decades. A better understanding of the biology of cancer has translated into development of novel systemic agents, as well a more effective use of older chemotherapy agents. As a consequence, cancer mortality continues to decrease. However, greater cure and disease control rates come at a price of an increased risk of adverse effects, which often affects the mouth and related structures including the oral mucosa, salivary glands, jawbones, and cranial nerves. Oral mucositis, hyposalivation, dysgeusia, and osteonecrosis of the jaw (ONJ) are some examples of th…