Dental turbine

The aim was to investigate the effect of machining instruments on machinability of dental ceramics. Four dental ceramics, including two zirconia ceramics were machined by three types (SiC, diamond vitrified, and diamond sintered) of wheels with a hand-piece engine and two types (diamond and carbide) of burs with a high-speed air turbine. The machining conditions used were abrading speeds of 10,000 and 15,000 r.p.m. with abrading force of 100 gf for the hand-piece engine, and a pressure of 200 kPa and a cutting force of 80 gf for the air-turbine hand-piece...

An intraosseous lipoma is a rare histologic variant of lipoma, accounting for only 0.1% of all primary bone tumors. This may not be the actual incidence because most of these lesions are frequently asymptomatic, but imaging modalities, such as computed tomography or magnetic resonance imaging (MRI) seem to have increased the detection rate. Lipoma occasionally undergoes osseous metaplasia and becomes an osseous lipoma. Although there are numerous papers discussing intraosseous lipoma and some authors have tried to differentiate lipomas from osseous lipomas, there is still a great deal of confusion with regard to characteristic radiologic features and the use of terms...

PURPOSE: The purpose of this study was to document malocclusion and facial dysmorphology in a series of patients with long face (LF) and chronic obstructive nasal breathing before treatment and the outcomes after bimaxillary orthognathic, osseous genioplasty, and intranasal surgery. MATERIALS AND METHODS: A retrospective cohort study of patients with LF undergoing bimaxillary, chin, and intranasal (septoplasty and inferior turbinate reduction) surgery was implemented...

PURPOSE: The purpose of this study was to evaluate heat generation at the implant surface caused by abutment preparation using a diamond bur in a high-speed dental turbine in vitro at 2 different water-coolant temperatures. MATERIALS AND METHODS: Thirty-two titanium-alloy abutments were connected to a titanium-alloy implant embedded in an acrylic resin placed within a water bath at a controlled temperature of 37°C. The specimens were equally distributed into 2 groups (16 each)...

PURPOSE: Maxillomandibular advancement (MMA) is an effective alternative for treating severe obstructive sleep apnea (OSA). However, the promotion of MMA in China is limited by many Chinese patients having a convex facial profile. To achieve maximal upper airway enlargement without an esthetic disaster, we added counterclockwise rotation of the maxillomandibular complex (MMC) in the routine MMA. In this paper, we have evaluated the objective and subjective outcomes of this technology...

OBJECTIVES: The maxillary sinus mucosa is reported to recover to preoperative sterility after sinus floor elevation. However, when drainage of maxillary sinus is impaired, recovery can be delayed and maxillary sinusitis can occur. Therefore, in this study, we investigated the correlations between anatomic variants that can interrupt the ostium of the maxillary sinus and incidence of complication after sinus lifting. MATERIALS AND METHODS: The subjects are 81 patients who underwent sinus lifting in Wonkwang University Dental Hospital (Iksan, Korea)...

Although less frequently encountered in dental practices, subcutaneous emphysema of the face and neck has been reported in patients following dental extractions, particularly when lower molar teeth are extracted with the use of a high-speed air-turbine drill designed for restorative treatment, which forces air into the cervical fascial spaces. As facial swelling and pain are the most common presentations, subcutaneous emphysema can often be misdiagnosed as an allergic reaction or odontogenic infection. While usually a benign and self-limiting condition, subcutaneous emphysema may have life-threatening complications such as tension pneumothorax, cardiac tamponade, air embolism, tracheal compression and mediastinitis, which are important to recognize in an emergency setting...

INTRODUCTION: The air-water syringes, ultrasonic scalers, high speed air turbine handpieces are connected to dental units by a network of small-bore plastic tubes through which water and air travel to activate or cool the instruments and it had been shown that this system is extensively contaminated with microbial biofilms and pose a potential risk of infection for patients as well as dental professionals. AIM: To evaluate and compare the efficacy of various disinfectants in reducing the microbial colony count in water derived from Dental Unit Waterlines...

Chemical disinfectants are widely advocated to reduce the microbial contamination in dental unit waterlines (DUWL). However, until now their efficacy has been poorly examined after long-term application. In this study, through quantitative PCR and high-throughput sequencing, both bacterial and fungal communities were profiled from 8-12 year-old DUWL treated with disinfectants commonly used by European dentists. Water was collected from the tap water supplying units to the output exposure point of the turbine handpiece following a stagnation period and dental care activity...

Histological studies of the lymphatic vascular system in adult mice are hampered because bones cannot be sectioned properly. Here, we decalcified the heads of 14-day-old mice, embedded them in paraffin and stained resultant serial sections with the lymphendothelial-specific antibodies Lyve-1 and Podoplanin. We show that the tissues with the highest lymphatic vascular density are the dermis and the oral mucous membranes. In contrast, the nasal mucous membrane is devoid of lymphatics, except for its most basal parts below the vomeronasal organ...

The sound produced by a dental air turbine handpiece (dental drill) can markedly influence the sound environment in a dental clinic. Indeed, many patients report that the sound of a dental drill elicits an unpleasant feeling. Although several manufacturers have attempted to reduce the sound pressure levels produced by dental drills during idling based on ISO 14457, the sound emitted by such drills under active drilling conditions may negatively influence the dental clinic sound environment. The physical metrics related to the unpleasant impressions associated with dental drill sounds have not been determined...

STATEMENT OF PROBLEM: Different surface treatments are commonly used during the fabrication of zirconia fixed dental prostheses. However, such treatments can affect the properties of the zirconia framework material. PURPOSE: The purpose of this in vitro study was to determine the effect of different surface treatments on the surface roughness and flexural and bend strength of zirconia. MATERIAL AND METHODS: Seventy-two zirconia disks (n=8) and 72 zirconia bars (n=8) were sintered and divided into 9 groups for different surface treatments: sintered control, airborne-particle abraded with 50-μm aluminum oxide, airborne-particle abraded with Rocatec soft (30 μm), airborne-particle abraded with Rocatec (105 μm), grinding dry with a micromotor, turbine grinding under water cooling, grinding with silicon carbide paper, diamond paste polishing, and steam cleaning...

STATEMENT OF PROBLEM: Laboratory studies of tooth preparation often involve single values for all variables other than the one being tested. In contrast, in clinical settings, not all variables can be adequately controlled. For example, a new dental rotary cutting instrument may be tested in the laboratory by making a specific cut with a fixed force, but, in clinical practice, the instrument must make different cuts with individual dentists applying different forces. Therefore, the broad applicability of laboratory results to diverse clinical conditions is uncertain and the comparison of effects across studies difficult...

PURPOSE: The purpose of the present study was to evaluate the indications, safety, and treating orthodontists' assessment of outcomes after bimaxillary orthognathic surgery that included segmental osteotomies. MATERIALS AND METHODS: We performed a retrospective cohort study of patients treated by a single surgeon from 2004 to 2013. The index group consisted of a consecutive series of subjects with a bimaxillary dentofacial deformity (DFD) involving the chin and symptomatic chronic obstructive nasal breathing...

BACKGROUND: Dental unit water (DUW) could be contaminated by human pathogens coming from biological fluids penetrated during patient treatment and by opportunistic pathogens detached from aquatic biofilm. These microorganisms could be spread to following patients. We tested the disinfectant activity of hydrogen peroxide and monovalent silver ions (H(2)O(2)-Ag(+)) into DUW artificially contaminated with freshly isolated pathogens. METHODS: The tested microorganisms were Staphylococcus aureus, Enterococcus faecalis, Candida albicans, Pseudomonas aeruginosa, Legionella pneumophila, Mycobacterium chelonae, non-pathogenic Bacillus clausii spores...

We have investigated the volumes of the nasal cavities of 35 patients treated with superior repositioning Le Fort I osteotomy by analysing cone-beam computed tomography (CT) data with a 3-dimensional reconstruction program to correlate changes in the volume of the nasal cavity that were associated with the maxillary superior repositioning and the role of outfracture of the inferior turbinates. The patients were treated at the Pusan National Dental Hospital during the 14-month period January 2011-March 2012...

Respiratory depression can occur during intravenous general anesthesia without tracheal intubation. A new acoustic method for respiratory rate monitoring, RRa(®) (Masimo Corp., Tokyo, Japan), has been reported to show good reliability in post-anesthesia care and emergency units. The purpose of this study was to investigate the reliability of the acoustic method for measurement of respiratory rate during intravenous general anesthesia, as compared with capnography. Patients with dental anxiety undergoing dental treatment under intravenous anesthesia without tracheal intubation were enrolled in this study...

Iatrogenic injuries of the frontal skull base commonly occur during endoscopic sinus surgery. In this paper, we present a rare case of cranial base injury after transnasal endotracheal intubation for dental surgery. A 61-year-old otherwise healthy man presented at the emergency department with headache, right leg weakness and watery nasal discharge on the left side. He underwent a dental surgery under general anaesthesia with transnasal endotracheal intubation 2 days earlier. A CT of the head showed a bone defect of the left skull base with a bifrontal pneumocephalus...

BACKGROUND: Infratemporal fossa abscess following odontogenic infection is not rare, and usually occurs as a sequela of dental disease. Infratemporal fossa abscess was previously treated with the combination of buccal incision and temporal incision, or via a transoral approach. METHOD: This paper reports a case of infratemporal fossa abscess in a 51-year-old female. RESULTS: The abscess was drained transnasally via an endoscopic modified medial maxillectomy approach, preserving the inferior turbinate and nasolacrimal duct...

Some infections cases due to exposure to output water from dental unit waterlines (DUWL) have been reported in the literature. However, this type of healthcare-associated risk has remained unclear and up until now the overall bacterial composition of DUWL has been poorly documented. In this study, 454 high-throughput pyrosequencing was used to investigate the bacterial community in seven dental offices (N = 7) and to identify potential bacterial pathogenic sequences. Dental unit waters (DUW) were collected from the tap water supplying units (Incoming Water; IW) to the output exposure point of the turbine handpiece (Output water; OW) following a stagnation period (OWS), and immediately after the last patient of the sampling day (OWA)...