PURPOSE: In literature, many studies compare survival rates of different types of FPDs. Most of them compared restorations, which originated from one university, but from different clinicians. Data about restoration survival rates by only one experienced dentist are very rare. The aim of this study was to evaluate the survival rate of allceramic FPDs without the blurring effects of different clinicians. MATERIALS AND METHODS: 153 veneeredzirconia FPDs were observed for follow-up. 22 patients received 131 single crowns and 22 bridges. Because of the different bridge lengths, one unit was defined as a restored or replaced tooth. In total, 201 units were included. Only the restorations performed by the same clinician and produced in the same dental laboratory from 2011 to 2016 were included. Considered factors were defined as “type of unit”, “type of abutment”, “intraoral region”, and “vitality”. Modified UHPHS criteria were used for evaluation. Statistical analysis was performed using cox-regression. RESULTS: 189 units (94.0%) showed no kind of failure. 5 chippings (2.4%) could be corrected by intraoral polishing. 4 units (1.9%) exhibited spontaneous decementation. These polishable and recementable restorations are still in clinical use. Chippings or decementations, which lead to total failure, did not occur. One unit was completely fractured (0.5 %). Biological failures (caries, periodontitis or periimplantitis) did not occur. The statistical analysis of the factors did not reveal any significant differences. CONCLUSION: Modern all-ceramic FPDs seem to be an appropriate therapy not only for single restorations but for complex occlusal rehabilitations.
Crowns ; Dentists ; Follow-Up Studies ; Humans ; Laboratories, Dental ; Periodontitis ; Survival Rate ; Tooth

The restoration of endodontically treated teeth (ETT) with more than one cusp missing and thin remaining walls is challenging for the general practitioner. The use of posts combined with full coverage restorations is a well-established approach, yet not following the minimal invasive principles of adhesive dentistry. Endocrowns are indirect monoblock restorations that use the pulp chamber of the ETT for retention. In this study the fabrication of 4 endocrowns and their clinical performance will be discussed. Two clinical cases include computer-aided design/computer-aided manufacturing manufactured molar endocrowns (one feldspathic ceramic and one hybrid composite-ceramic restoration) and the other two are dental laboratory manufactured resin composite premolar endocrown restorations. The modified United States Public Health Service criteria were used to assess the clinical behavior of the restorations at different follow up periods. Endocrown restorations present a satisfactory clinical alternative, either by the use of resin composite or glass ceramic and hybrid materials. Specific guidelines with minimal alterations should be followed for an endocrown restoration to be successful. Due to limited evidence regarding the long term evaluation of this restorative technique, a careful selection of cases should be applied.
Adhesives ; Bicuspid ; Ceramics ; Composite Resins ; Computer-Aided Design ; Dental Pulp Cavity ; Dentistry ; Endodontics ; Follow-Up Studies ; General Practitioners ; Glass ; Humans ; Laboratories, Dental ; Molar ; Tooth* ; United States Public Health Service

This article reviews the topic of how to identify and develop a removable partial denture (RPD) path of placement, and provides a literature review of the concept of the RPD path of placement, also known as the path of insertion. An optimal RPD path of placement, guided by mutually parallel guide planes, ensures that the RPD flanges fit intimately over edentulous ridge structures and that the framework fits intimately with guide plane surfaces, which prevents food collecting empty spaces between the intaglio surface of the framework and intraoral surfaces, and ensures that RPD clasps engage adequate numbers of tooth undercuts to ensure RPD retention. The article covers topics such as the causes of obstructions to RPD intra-oral seating, the causes of food collecting empty spaces that may exist around an RPD, and how to identify if a guide plane is parallel with the projected RPD path of placement. The article presents a method of using a surgical operating microscope, or high magnification (6-8x or greater) binocular surgical loupes telescopes, combined with co-axial illumination, to identify a preliminary path of placement for an arch. This preliminary path of placement concept may help to guide a dentist or a dental laboratory technician when surveying a master cast of the arch to develop an RPD path of placement, or in verifying that intra-oral contouring has aligned teeth surfaces optimally with the RPD path of placement. In dentistry, a well-fitting RPD reduces long-term periodontal or structural damage to abutment teeth.
Dentistry ; Dentists ; Denture, Partial, Removable* ; Dentures ; Humans ; Laboratories, Dental ; Lighting ; Prosthodontics ; Telescopes ; Tooth

PURPOSE: The purpose of this study was to measure the tightening torque for dental implant in dental laboratory and to analyze of the effects of different tightening torque. MATERIALS AND METHODS: The tightening torque for dental implant in dental laboratory were measured by digital torque gauge. The length of abutment and analog were measured as tightening torque of manufacturer's instructions and the measured value. And the data were statically analyzed. RESULTS: The mean tightening torque of implant screw in dental laboratory was 1.563 +/- 0.332 Ncm. The external type implant system of total length were showing no significant differences but the internal type implant system had difference significant (P < 0.05) when compared with tightening torque. CONCLUSION: The implant prosthesis should be made under manufacturer's instructions especially as tightening torque of screw. For the fidelity of implant prosthesis, dental technician should learn how to use the torque gauge.
Dental Implants ; Dental Prosthesis ; Dental Technicians ; Humans ; Laboratories, Dental* ; Prostheses and Implants ; Torque*

PURPOSE: To evaluate the efficacy of sodium hypochlorite (1 : 10) and iodophor disinfectants on alginate impressions along with their effect on the survived bacterium count on the gypsum cast. MATERIALS AND METHODS: Four alginate impression on each dentate patients were made, of which Group I were not washed or disinfected, Group II impressions were merely washed with water, Group III were disinfected by spraying with sodium hypochlorite (1 : 10), Group IV were disinfected with iodophor (1 : 213). Gypsum cast (type III) were made from all the impression. Impressions and gypsum cast were swabbed in mid palatal region for bacterial culture. Bacterial colony counting done after 3 days of incubation at 37degrees C in blood agar media. The data obtained was analyzed by one way ANOVA test at a significant difference level of 0.05. RESULTS: Group I and Group II showed significantly more bacteria compared to Group III and Group IV. Bacterial colonies on the alginate impression and gypsum cast in group disinfected with Sodium hypochlorite (1 : 10) were 0.18, 0.82 respectively compared to group treated with iodophor (1 : 213). There was an increase in bacterial count on dental cast compared to source alginate impressions. CONCLUSION: Sodium hypochlorite (1 : 10) was found to be better disinfectant for alginate impression. There was an indication of increase in number of bacteria from alginate impression to making of dental cast. Additional gypsum cast disinfectant procedures need to be encouraged to completely eliminate cross infection to dental laboratory.
Agar ; Alginates ; Bacteria ; Bacterial Load ; Calcium Sulfate ; Cross Infection ; Disinfectants ; Disinfection ; Glucuronic Acid ; Hexuronic Acids ; Humans ; Infection Control ; Laboratories, Dental ; Sodium Hypochlorite ; Water

OBJECTIVES: This cross-sectional study was performed in the Dental School of Prince of Songkla University to ascertain noise exposure of dentists, dental assistants, and laboratory technicians. A noise spectral analysis was taken to illustrate the spectra of dental devices. METHODS: A noise evaluation was performed to measure the noise level at dental clinics and one dental laboratory from May to December 2010. Noise spectral data of dental devices were taken during dental practices at the dental services clinic and at the dental laboratory. A noise dosimeter was set following the Occupational Safety and Health Administration criteria and then attached to the subjects' collar to record personal noise dose exposure during working periods. RESULTS: The peaks of the noise spectrum of dental instruments were at 1,000, 4,000, and 8,000 Hz which depended on the type of instrument. The differences in working areas and job positions had an influence on the level of noise exposure (p < 0.01). Noise measurement in the personal hearing zone found that the laboratory technicians were exposed to the highest impulsive noise levels (137.1 dBC). The dentists and dental assistants who worked at a pedodontic clinic had the highest percent noise dose (4.60 +/- 3.59%). In the working areas, the 8-hour time-weighted average of noise levels ranged between 49.7-58.1 dBA while the noisiest working area was the dental laboratory. CONCLUSION: Dental personnel are exposed to noise intensities lower than occupational exposure limits. Therefore, these dental personnel may not experience a noise-induced hearing loss.
Cross-Sectional Studies ; Dental Assistants ; Dental Clinics ; Dental Instruments ; Dentists ; Hearing ; Hearing Loss, Noise-Induced ; Humans ; Laboratories, Dental ; Laboratory Personnel ; Noise ; Occupational Exposure ; Schools, Dental ; United States Occupational Safety and Health Administration

The purpose of this study was to investgate and evaluate whether the recording information contained in the work authorization was performed properly and master casts were designed accurately according to the rationale and principles of the removable partial denture when the work authorization and the master casts were sent to the dental framework. the accurate recording of the work authorization sent to dental laboratory in Hwasun for removable partial denture framework, the normal form of the occlusal rest guiding plan of the surveyed crown using the surveyor, the location analysis of the occlusal rest seat, the design patten of the maxillary and mandibulary major connectors, the use of the surveyor on the master cast, the status of the secondary impression taken in the distal extension edentulous areas were investigated for this study. The following results were obtained : 1. In the status of the occlusal rest seat prepared in the abutment, the occlusal rest seat with normal form was 81.25%, 95.45%, that without form was 6.25%, 0.00%, respectively in Class I and Class II on the maxillary cast and the occlusal rest seat with normal form was 76.92%, 95.45%, that without form was 7.69%, 0.00% respectively in Class I and Class II on the mandibular cast. 2. In the status of the guiding plan, the guiding plan with the normal form was 79.17%, 86.36% that with abnormal form was 20.84%, 13.64% respectively in Class I and Class II on the maxillary cast and the guiding plan with normal form was 79.49%, 77.27%, that with abnormal form was 20.51%, 22.73% respectively in Class I and Class II on the mandibular cast. 3. The abutment splinting in the distal extension removable partial denture was 20.78%, 27.27%, respectively in Class I and Class II on the maxillary cast and was 25.64%, 13.64% respectively in Class I and Class II on the mandibular cast. 4. The location and form of the major connector delineated on the maxillary and mandibular master cast was 95.83%, 98.41% respectively. 5. The delineation and recording on the work authorization was incomplete as group II(73.33%), group I(14.07%), group III(12.59%) and group IV (0.00%) in investigating the contents of the work authorization. 6. Aker's clasp of the types of the direct retainer was nots used 72.22%, 74.60%, in the maxillary and mandibular casts respectively. 7. The location of the indirect retainer delineated on the maxillary and mandibular master cast was 51.43%, 50.82% respectively. 8. The types of metal used were mostly Cr-Co non-precious metal alloy and the cases using color coding on the drawing paper of work authorization were not observed. 9. The cases taking secondary impression in the distal extension removable partial denture were 45.71%, 52.46% respectively in the maxillary and mandibular master cast. 10. The delineation of tripoding or reference line on the master cast was not observed in surveying procedure.
Alloys ; Clinical Coding ; Crowns ; Denture, Partial, Removable ; Laboratories, Dental ; Splints

The purpose of this article is to introduce a new virtual orthodontic treatment (VOT) system, which can be used to construct three-dimensional (3D) virtual models, establish a 3D virtual setup, enable the placement of the virtual brackets at the predetermined position, and fabricate the transfer jig with a customized bracket base for indirect bonding (IDB) using the stereolithographic technique. A 26-year-old woman presented with anterior openbite, crowding in the upper and lower arches, and narrow and tapered upper arch, despite having an acceptable profile and balanced facial proportion. The treatment plan was rapid palatal expansion (RPE) without extraction. After 10 days of RPE, sufficient space was obtained for decrowding. After a 10-week retention period, accurate pretreatment plaster models were obtained using silicone rubber impression. IDB was performed according to the protocol of the VOT system. Crowding of the upper and lower arches was effectively resolved, and anterior openbite was corrected to normal overbite. Superimposition of the 3D virtual setup models (3D-VSM) and post-treatment 3D virtual models showed that the latter deviated only slightly from the former. Thus, the use of the VOT system helped obtain an acceptable outcome in this case of mild crowding treated without extraction. More cases should be treated using this system, and the pre- and post-treatment virtual models should be compared to obtain feedback regarding the procedure; this will support doctors and dental laboratory technicians during the learning curve.
Adult ; Crowding ; Female ; Humans ; Laboratories, Dental ; Learning Curve ; Open Bite ; Overbite ; Retention (Psychology) ; Silicone Elastomers

OBJECTIVES: In most DEHP exposure assessment studies, single spot urine sample was used. It could not compare the exposure level among studies. Therefore, we are going to represent the necessity of selection of proper sampling time of spot urine for assessing the environmental DEHP exposure, and the association urinary DEHP metabolites with steroid hormones. METHODS: We collected urine and plasma from 25 men. The urine sampling times were at the end of the shift (post-shift) and the next morning before the beginning of the shift (pre-shift). Three metabolites of DEHP {mono(2-ethylhexyl) phthalate [MEHP], mono-(2-ethyl-5-hydroxyhexyl)phthalate [MEHHP], and mono(2-ethyl-5-oxohexyl)phthalate [MEOHP]} in urine were analyzed by HPLC/MS/MS. Plasma luteinzing hormone, follicle stimulating hormone, testosterone, and 17beta-estradiol were measured at pre-shift using a ELISA kit. A log-transformed creatinine-adjusted urinary MEHP, MEHHP, and MEOHP concentration were compared between the post- and pre-shift. The Pearson's correlation was calculated to assess the relationships between log-transformed urinary MEHP concentrations in pre-shift urine and hormone levels. RESULTS: The three urinary metabolite concentrations at post-shift were significantly higher than the concentrations in the pre-shift (p<0.0001). The plasma hormones were not significantly correlated with log-transformed creatinine - adjusted DEHP metabolites. CONCLUSIONS: To assess the environmental DEHP exposure, it is necessary to select the urine sampling time according to the study object. There were no correlation between the concentration of urinary DEHP metabolites and serum hormone levels.
Adult ; Diethylhexyl Phthalate/analogs & derivatives/pharmacokinetics/*urine ; Estradiol/blood ; Follicle Stimulating Hormone/blood ; Humans ; *Laboratories, Dental ; Luteinizing Hormone/blood ; Male ; Middle Aged ; Occupational Exposure/*analysis ; Phthalic Acids/urine ; Specimen Handling/*methods ; Testosterone/blood ; Time Factors

PURPOSE: The primary objective in applying surgical splints is the restoration of normal occlusal relations through proper positioning of the teeth and bony structures. The splints were fabricated by specially educated physicians and personnel with dental training or a dental laboratory. The aim of this article is to introduce the easy availability and fabrication method of acrylic splints. METHODS: Acrylic is the most easily, rapidly, and cheaply obtained material among various splints. Acrylic splints are especially rigid, strong, easily adjustable and repairable, translucent, light-weighted, and well tolerated by the oral mucosa. Thus, the use of acrylic occlusal splints have been popularly applied. RESULTS: Surgical prosthetic splints have been used in the following; treatment of complex facial bone fractures, correction of maxillomandibular disharmonies, segmental maxillary osteotomies, reconstruction of the mandible, treatment of mandibular fractures in children, night guards in sleep bruxism, and repairment of TMJ dysfunctions. CONCLUSION: The use of acrylic splints have been popularly applied because of its good aspects and various purposes. However, its use is restricted because the process is time consuming, costly, and absolutely dependent on a dental technician in plastic surgery. This article presents the easy construction of splints made directly by the operator so that it may help analyze the patient's occlusion on dental casts and aid in building an operation plan.
Child ; Dental Technicians ; Facial Bones ; Humans ; Laboratories, Dental ; Mandible ; Mandibular Fractures ; Maxillary Osteotomy ; Mouth Mucosa ; Occlusal Splints ; Sleep Bruxism ; Splints* ; Surgery, Plastic ; Temporomandibular Joint ; Tooth