Three-dimensional evaluation of sleep bruxism-related splint wear using a dental laboratory scanner: A preliminary clinical study.

BACKGROUND: The wear depth on the occlusal splint (OS) is reportedly associated with the sleep bruxism (SB) level, as evaluated using portable polysomnography (PSG) recordings. However, the OS is deformed owing to SB forces, possibly preventing the accurate quantification of the wear facets. OBJECTIVES: We aimed to introduce a newly developed system to quantify the wear facets on the OS using a dental laboratory scanner (D810) and investigate the association between the wear facets, as evaluated with this system, and the SB level. METHODS: Ten healthy individuals who were diagnosed with SB based on portable PSG recordings participated in this study. They were asked to wear the OS for 2 months. The first day after a 2-week adaptation period was defined as the reference day, and sequential scanning of the OS surface was performed on days 15, 30, and 45. Changes in the OS surface from the reference day allowed dimensional evaluation of the wear facets in terms of maximum wear depth, wear area, and wear volume. Multiple regression analyses were conducted to test whether each of these variables could be predicted by any of the SB-related variables. RESULTS: The total duration of SB episodes per hour of sleep and the maximum muscle activity were significantly associated with the wear area, as measured with our system (adjusted R-squared was .78, p < .01). CONCLUSION: Our system allows dimensional analysis of the wear facets on the OS surface in association with the SB level.

Factors related to sharps injuries among students in a dental laboratory.

Clarification of potential factors affecting the occurrence of accidental sharps injuries among students in dental laboratories would likely help to reduce the incidence of such injuries, thus improving dental education, as well as further preventing injury in general healthcare workspaces. In this study, undergraduates at the College of Oral Medicine, Taipei Medical University, were assessed for 10 items: gender, age, course specialty, whether or not framed glasses were worn during operations, speed of assignment completion, dominant hand, self-assessment of performance, whether or not students previewed the classes in advance, sleep duration, and sharps injury experience. The results suggested that course specialty and sleep duration were the major factors associated with the occurrence of sharps injuries among students in the dental laboratory.

Bioseguridad en el laboratorio dental / Biosafety in the dental laboratory

Una enfermedad infecciosa es aquella producida por un agente infeccioso (bacterias, hongos, virus, etc.) que ingresa y se desarrolla en el organismo de un hospedero. Posteriormente, puede trasmitirse de un individuo a otro directamente por contacto entre ambos, o bien, indirectamente, por medio de un vec-tor biológico (de naturaleza animal o vegetal), o de un fómite (objeto inanimado). Las vías por las que un agente infeccioso puede ingresar a un hospedero son: inhalación (respiración de aerosoles), ingestión (salpicaduras de gotas), penetración de mucosas (na-sal, ocular y bucal) o lesiones en la piel o mucosas. Las fuentes de infección pueden ser los pacientes, el personal del consultorio o laboratorio, las superficies e instrumental contaminados y las prótesis o com-ponentes de éstas. Para evitar la propagación de los agentes microbianos se debe interrumpir el proceso de transmisión de los mismos. Todo profesional debe fortalecer y readecuar normas y protocolos de biose-guridad en la tarea diaria, para minimizar el riesgo de transmisión directa y cruzada entre el profesional, su equipo auxiliar, el laboratorista y los pacientes (AU)

An infectious disease is one caused by an infectious agent (bacteria, fungi, virus, etc.) that enters and develops in a host. Then it can be transmitted from one individual to another directly by contact between the two or, indirectly through a biological vector (an animal or plant nature), or a fomite (an inanimate object). The routes by which an infectious agent can enter a host are: inhalation (breathing of aerosols), ingestion (splash of droplets), penetration of mucous membranes (nasal, ocular and oral) and skin or mucous lesions. Sources of infection can be patients, office or laboratory personnel, contaminated surfaces and instruments and the prosthesis or component thereof. To prevent the spread of microbial agents, the process of their transmission must be interrupted. Every professional must strengthen and readjust biosafety standards and protocols in daily work to minimize the risk of direct and cross-transmission between the professional, his auxiliary team, the laboratory technician and the patients (AU)

Abutment Screw Loosening Due to Dental Laboratory Error.

Abutment screw loosening (ASL) is a fairly common problem that adversely affects the longterm success of a dental implant restoration. Dental laboratory error can play a role in the etiology of ASL. This article presents three cases that demonstrate how laboratory errors in the fabrication of implant restorations and mismanagement of abutment surfaces can result in ASL. It describes a method for examination of the abutment surface.

Technical Accuracy of Dental Laboratories in the Quality and Shade Matching of Porcelain Fused to Metal Crowns: An In Vitro Study.

Dental laboratories (LABs) are integral to the performance of a dentist in providing successful oral rehabilitation. The aim of this study was to compare the adaptation, contour, contacts, and shade matching of different government and commercial dental LABs in the fabrication of porcelain fused to metal (PFM) crowns. Thirty-two dental LABs were selected to fabricate PFM crowns (one PFM crown each). Marginal adaptation, contour, proximal contacts, and shade matching were evaluated. Evaluation of the crowns' quality was performed following modified USPHS/FDI criteria. Visual and colorimeter assessments were employed to evaluate shade matching. Differences between groups were examined by Pearson's Chi-square and Fisher's exact test. The quality of marginal adaptation of crowns was good in 81.25%, however the quality of contours, contacts, and shade matching was compromised in 43.75%, 59.38%, and 39% of all LABs, respectively. Visual and colorimeter shade matching was acceptable in 62.5% and 80% of LABs in the cervical third and middle third regions of crowns, respectively, however in the incisal third the shade matching was unacceptable in nearly 60% of LABs. Commercial laboratories showed significantly better contours and shade matching, but not marginal adaptation. However, no significant differences were found in comparison of proximal contacts between the groups.

A Technique to Record and Transfer the Distance Between the Bone Crest and the Interproximal Contact Point to the Dental Laboratory to Maintain the Interdental Papilla While Fabricating Implant Supported Restorations.

The interdental papilla plays an important role in terms of esthetics and function. Management of the interdental papilla, especially around implants can be challenging. One of the factors mentioned in the literature that affects the viability of the papilla is the distance of the interdental contact point from the crest of the bone. The following case report describes a technique to predictably achieve an interdental contact area within the proper distance from the crest of the bone to help maintain the papilla for the long term.

Presencia de bacterias en prótesis dentales durante el proceso de elaboración / Presence of bacteria in dental prostheses during the elaboration process

Existe una creciente preocupación sobre el tema de la infección cruzada en clínicas y laboratorios dentales. El laboratorio odontológico debe seguir normas de bioseguridad que garanticen a todo el equipo de salud la prevención de estas infecciones. Los técnicos que allí laboran corren el riesgo de exponer su cara a salpicaduras, así como a rocíos de sangre y saliva. Este estudio fue diseñado para saber si los laboratorios a los que recurrimos cumplen con estas normas de bioseguridad, y qué tan confiados podemos estar de la desinfección por parte de ellos, ya que las prótesis deberían estar desinfectadas correctamente antes de colocarlas en boca (AU)

There is growing concern about the issue of cross infection in dental clinics and laboratories. The dental laboratory must follow biosafety standards that guarantee the prevention of these infections to the entire health team. The technicians who work there run the risk of exposing their face to splashes and spray of blood and saliva. This study was designed to find out if the laboratories we use comply with these biosafety standards, and how confident we can be of their disinfection by them, since the prostheses should be properly disinfected before placing them in the mouth (AU)

Suitability of the triple-scan method with a dental laboratory scanner to assess the 3D adaptation of zirconia crowns.

STATEMENT OF PROBLEM: The triple-scan method for assessing the 3D adaptation of dental restorations has been introduced and reported to be reliable. However, the suitability of using a dental laboratory scanner in the triple-scan method has not been evaluated. PURPOSE: The purpose of this in vitro study was to evaluate the suitability of the triple-scan method using a dental laboratory scanner to assess the 3D adaptation zirconia crowns. MATERIAL AND METHODS: A zirconia abutment and a zirconia crown were fabricated, and the abutment was fixed in a custom-made base. The crown was seated onto the abutment with the interposition of light-body silicone impression material between them. The triple-scan method was performed by using a dental laboratory scanner, and the mean cement-gap thickness was calculated. The seating and digitalization process was repeated 10 times, and after each digitalization, the light-body silicone layer was stabilized by applying heavy-body silicone impression material over it. Cement-gap thickness was measured on cross-sections of the aligned scan data sets and of the physical silicone replica. The results were assessed by using the paired t test and the Bland-Altman method (α=.05). RESULTS: Mean 3D cement-gap thickness assessed by the triple-scan method reported small dispersion with a coefficient of variation of 5.6% for the occlusal area, 1.9% for the axial area, and 6.4% for the margin area. Cement gap thickness measured at corresponding locations in the aligned scan data sets and in the physical silicone replica reported no significant difference (P=.326) and good agreement. CONCLUSIONS: The cement gap was accurately duplicated in scan data sets. The triple-scan method by using a dental laboratory scanner is suitable for assessing the 3D adaptation of zirconia crowns.

Laboratory Trends for Removable Prosthodontics: A Comparison of Two Surveys.

PURPOSE:  The purpose of this survey was to assess dental laboratory technicians' perceptions of the quality of communication and techniques used when receiving removable prosthodontic cases. Additionally, responses were compared to a 2009 survey and changes in trends were evaluated. MATERIALS AND METHODS:    An eleven-question anonymous response survey was developed based on a 2009 survey that assessed dental laboratory technicians' perceptions.  The survey was distributed via Qualtrics to members of the National Association of Dental Laboratories (NADL) The survey included questions related to detail of instruction, quality of work received, design of the prosthesis, and type of articulator used.  Responses were compared to those received in 2009. RESULTS:  Fifty-two survey responses were received from dental laboratory technicians. Of these, 12 did not provide removable prosthodontics services and were excluded. The remaining 40 responses were analyzed. Of these, only 3.7% of the responding laboratory technicians reported receiving work authorizations from dentists that were complete enough to do their best work. While roughly half of the respondents (48.49%) expected a dentist to send a design for a cast partial denture framework, most respondents (72.5%) answered that they designed the majority of the partial denture frameworks they fabricated. The majority of respondents reported that complete denture impressions were not border molded in custom trays, and that most dentists did not rearrange or modify a wax setup for complete or partial dentures. These findings were consistent with the trends reported in the 2009 survey. CONCLUSIONS:  Most dental laboratory technicians answered that based on their selected techniques, dentists tend to complete clinical procedures that minimize patient chair time. While the surveyed technicians appeared satisfied with the quality of work they received, there was a consistent message that communication was frequently inadequate, limiting the technicians ability to fabricate their best work.

Dentist-laboratory communication and quality assessment of removable prostheses in Oregon: A cross-sectional pilot study.

STATEMENT OF PROBLEM: When fabricating a removable dental prosthesis, it is unclear if the information received by the dental laboratory technician is clear and sufficient. PURPOSE: The purpose of this survey study was to evaluate the dentist's work authorizations for removable prostheses as well as determine common practices used by laboratories during the fabrication of removable prostheses. MATERIAL AND METHODS: A 24-item questionnaire was developed based on previously published questionnaires and incorporating new topics. A public uniform resource locator (URL) survey link was generated and sent to the office of the Oregon Association of Dental Laboratories (OADL). The executive director of the board then sent out the link to 163 participants that included members and nonmembers of the OADL who were still active in the state of Oregon. Two reminder e-mails were sent 2 weeks apart. Study data were collected and managed by using the Research Electronic Data Capture (REDCap) software program. Descriptive statistics were tabulated, and responses displayed as a percentage of the total. RESULTS: From the 163 invited participants, 26 responded to the survey representing a 15.9% response rate. Only 11% of the laboratories stated that they routinely receive work authorizations with clear instructions. All participants stated that they always (62.5%) or frequently (37.5%) design the partial prostheses frameworks. Only 37.5% of the laboratories stated that they usually receive adequately extended and accurate definitive casts to fabricate the framework. Fifty percent of the laboratories stated that they very rarely perform altered cast procedures and 50% indicated that half or more of the removable partial prostheses they fabricate were entirely made of acrylic resin. Most laboratories stated that thermoplastic resin partial dentures were less than 25% of their produced volume of removable prostheses. Only 22% of respondents stated that they usually receive adequate information to complete a denture tooth arrangement and most (78%) dentists do not routinely specify the type of occlusal scheme desired for their complete denture tooth arrangements. In most prostheses (77%), posterior palatal seal was marked by the prescribing dentists rarely or very rarely. CONCLUSIONS: Work authorizations provided by the dentists were less than adequate and left much decision-making to the dental laboratory technician.

Procedimentos operacionais padrão em prótese dentária: proposta de elaboração e implementação para a Secretaria Municipal de Saúde do Rio de Janeiro / Standart operating procedures in dental prosthesis: proposal for for preparation and implemantation for the Municipal Health Secretary of Rio de Janeiro

A presente pesquisa exploratória objetivou padronizar os processos de trabalho dos quatro Laboratórios Regionais de Prótese Dentária (LRPDS) que prestam apoio terapêutico à Saúde Bucal da Secretaria Municipal de Saúde (SMS) do Rio de Janeiro em atendimento ao requerimento de consultoria da Coordenação de Saúde Bucal (CSB) endereçado ao Mestrado Profissional em Clínica Odontológica da Universidade Federal do Rio de Janeiro (MPCOUFRJ) para revisão, avaliação, implementação e elaboração formulários estatísticos e de procedimentos operacionais padrão relacionados à especialidade de Prótese Dentária. Para o desenvolvimento do trabalho proposto os LRPDs foram visitados, proporcionando coletas e análises de dados do funcionamento das unidades; que foram apresentados e discutidos em reunião com a CSB. A partir dos dados coletados e analisados resultaram nos produtos técnicos e formulários necessários para a otimização dos processos de trabalho, e que foram apresentados em treinamento das equipes responsáveis pelos serviços de prótese dentária do Rio de Janeiro (RJ). Os levantamentos do estudo evidenciaram ausência de programa de gestão de resíduos de saúde por 3 das 4 unidades referidas, subnotificação e não utilização de códigos de faturamento de produção perante o Sistema Único de Saúde (SUS), ausência de padrão nos formulários de atendimento, das relatorias estatísticas, do controle de insumos e material permanente. Os problemas identificados por deste estudo, bem como sugestões para a melhoria, ampliação e democratização no acesso aos serviços de prótese dentária oferecidos à população foram levados ao conhecimento da Coordenação de Saúde Bucal (CSB), que considerou atendida a sua demanda. (AU)

The aim of this exploratory research was to standardize the work processes of the four Regional Dental Prosthesis Laboratories (LRPDS) that provide oral health therapeutic support to Rio de Janeiro City Health Department Council (SMS), in compliance with the consultancy requirement from the Oral Health Coordination (CSB) forwarded to the Federal University Professional Master's Degree Course in Clinical Dentistry of Rio de Janeiro (MPCO-UFRJ), to review, evaluate, improve and develop statistical forms and standard operating procedures related to the of Dental Prosthesis specialty. For the development of the proposed work, were visited the LRPDs, providing data collection and analysis of the operation of units; which were presented and discussed in a meeting with the CSB. From the data collected and analyzed resulted in the technical products and forms necessary for the optimization of work processes, and which were presented in training for the teams responsible for dental prosthesis services in Rio de Janeiro (RJ). The study surveys evidenced the lack of a health waste management program by 3 of the 4 units mentioned, under-notification and non-use of production billing codes before the Unified Health System (SUS), non-standard documents such as statistical reporting forms, control of supplies and permanent material. The problems identified by this study, as well as suggestions for the improvement, expansion and access democratization to dental prosthesis services offered to the population were brought to the attention of the Oral Health Coordination (CSB), which considered it´s demand answered. (AU)

Importing Automated Management System to Improve the Process Efficiency of Dental Laboratories.

Dental laboratories require manpower resources for manufacturing prostheses and inventory management. In this paper, we developed an automated inventory management system for dental laboratories to improve the production efficiency. A sensing system was developed based on the framework of Internet of things to collect the information of cobalt-chromium disks both in the storage room and manufacturing area, and an expert system was developed to automatically conduct inventory management based on the established rules. The proposed system can reduce the time of recording data and also assist the manager in configuring and managing material orders. The experimental results showed that a large amount of working time is reduced, resulting in the benefits of saving money and improving efficiency in dental manufacturing.

Quantitative Analysis of Selected Microorganisms Present at Various Sites in a Prosthetics Clinic and Dental Laboratory during Complete Denture Fabrication.

Background: Contamination with oral commensals and pathogenic microorganisms, and cross contamination between clinic and laboratory can occur. The amount of contamination has not been determined. Methods: Samples from different clinical and laboratory stages before and after disinfection (17 sites, 10 samples per stage) were collected. Laboratory surfaces and equipment were swabbed for 10 days (11 sites). Swabs were cultured for total mixed flora, Streptococci, Lactobacilli, Staphylococcus aureus, aerobic Gram-negative bacteria (AGNB) and Candida. Knowledge of infection control among staff and students was assessed. Results: Clinic: In total, 30-40% of the samples overall were contaminated with mixed flora and Streptococci of >100 cfu/swab; >100 cfu of AGNB and Candida were present on 6% and 1% of samples; 2% contained <100 cfu of S. aureus. Laboratory: In total, 17-48% of the samples overall were contaminated with mixed flora and Streptococci of >100 cfu/swab; >100 cfu of AGNB were present on 11% of samples; none contained >100 cfu of Candida. Disinfection significantly reduced the level of all organisms. Knowledge of infection control was sufficient, but compliance was poor. Conclusion: Although the count of mixed flora was high, potential pathogens such as S. aureus and Candida were low. In immunocompromised patients, this can become a problem.

Fracture rate of 188695 lithium disilicate and zirconia ceramic restorations after up to 7.5 years of clinical service: A dental laboratory survey.

STATEMENT OF PROBLEM: The use of ceramic materials has increased significantly because of high esthetic demands, low costs, and ease of fabrication. Long-term, clinically based evidence is scarce, and laboratory studies have limited relevance in determining clinical durability. PURPOSE: The purpose of this dental laboratory survey was to evaluate the fracture rate of layered and monolithic lithium disilicate and zirconia single crowns and fixed partial dentures after up to 7.5 years of clinical service. MATERIAL AND METHODS: Two commercial dental laboratories with a database system that was able to track the number of remakes because of fracture only were identified. Lithium disilicate restorations (monolithic and layered) were categorized according to restoration type (single crown, fixed partial denture, veneer, and onlay). Zirconia restorations (monolithic and layered) were categorized according to type (single crown, fixed partial denture) and then into anterior or posterior restoration. Restoration remakes due to poor fit, shade, or marginal integrity were excluded from the evaluation. Data were analyzed, and statistical significance was evaluated with chi-square tests (α=.05). RESULTS: A total of 188 695 (51 751 lithium disilicate and 136 944 zirconia) restorations were included in the analysis, with an overall fracture rate of 1.35%. Lithium disilicate monolithic single crowns had a fracture rate of 0.96%, which was significantly lower than that of layered single crowns at 1.26% (P<.05). When the different types of lithium disilicate restorations were compared, fixed partial denture (monolithic and layered) fracture rates were significantly higher than those of single crowns (P<.001). Monolithic zirconia single crowns (0.54%) fractured at a lower rate than layered zirconia single crowns (2.83%) and monolithic fixed partial dentures (1.83%) (P<.001), while layered single crowns (2.83%) had a higher fracture rate than that of layered fixed partial dentures (1.93%) (P<.001). Monolithic anterior and posterior zirconia restorations fractured at a lower rate than layered anterior and posterior zirconia restorations (P<.05). Posterior monolithic zirconia restorations fractured at a lower rate than anterior restorations, while posterior layered zirconia restorations fractured at a higher rate than anterior zirconia restorations (P<.05). CONCLUSIONS: Within the 7.5-year period, restorations fabricated with lithium disilicate and zirconia restorations had relatively low fracture rates. Monolithic restorations fractured at a lower rate than layered restorations.

Comparison of nonscheduled, postinsertion adjustment visits for complete dentures fabricated with conventional and CAD-CAM protocols: A clinical study.

STATEMENT OF PROBLEM: Unscheduled denture-adjustment visits may disrupt both patients and clinicians. Denture-adjustment visits have not been correlated with denture-processing methods. PURPOSE: The purpose of this clinical study was to identify differences in the number of unscheduled postinsertion-adjustment visits of patients with complete dentures fabricated by injection molding (IM) versus dentures fabricated by computer-aided design and computer-aided manufacturing (CAD-CAM). MATERIAL AND METHODS: One hundred six participants were evaluated in the study. They were consecutively treated in a private practice setting and followed up for 1 year after the insertion of new complete dentures. The first 33 received dentures fabricated using an IM system, and the other 73 were milled using a CAD-CAM system. All participants had been edentulous for at least 1 year. Participant ages ranged from 29 to 83 years. IM dentures were fabricated by a commercial dental laboratory; CAD-CAM dentures were milled by a commercial manufacturer. All participants were scheduled for 1- or 2-week postinsertion office visits. Further adjustment visits were scheduled according to participant request. The results were tabulated, and univariable tests of association were performed including chi-square and the Fisher exact tests for categorical comparisons and the Wilcoxon rank sum test for comparison of ordinal continuous data. A multivariable logistic regression model was used to control for the influence of multiple predictor variables on the outcome of interest. RESULTS: Edentulous years ranged from 1 to 60. Approximately one half (n=56) of all participants returned for scheduled postinsertion visits approximately 1 to 2 weeks after insertion of the dentures. No significant demographic or clinical differences were noted between participants receiving CAD-CAM or conventional dentures. Return visits for unscheduled adjustments were not associated with the method of denture fabrication or any other demographic features (P=.55). CONCLUSIONS: Based on the results of this study, there were no significant differences in the number of unscheduled, postinsertion visits for participants whose dentures were fabricated following IM or CAD-CAM milling protocols. Clinicians may choose to fabricate complete dentures with either protocol and expect similar clinical results in terms of the number of unscheduled postinsertion visits.

Use of Digital Technology to Improve Objective and Reliable Assessment in Dental Student Simulation Laboratories.

The aim of this study was to assess inter-and intra-grader agreement with the use of digital scanning and a tooth preparation assessment software program in comparison to the current traditional visual grading method in a dental student simulation laboratory. Students' typodont teeth preparations from previous practical examinations were used (cast crown n=50; cast fixed partial denture abutments n=50). Five preclinical instructors received calibration training and evaluated each of the preparations by the traditional visual grading method using a rubric. The same preparations were assessed by the same instructors using a tooth preparation assessment software program (PrepCheck, Sirona). The results showed that intra-grader agreement was significantly higher when grades were determined by PrepCheck compared to the traditional visual grading method. The traditional method was associated with significantly greater inter-grader disagreement in comparison to grading using PrepCheck (p<0.05). When the average final grade for students' crown preparations by each grader was compared for the traditional method and PrepCheck, significant differences were found for all graders (p<0.001). In this study, the use of the PrepCheck software program greatly improved intra-and inter-grader agreement during grading in a student simulation laboratory. Digital technology may improve the objectivity and reliability of assessments by preclinical evaluators.

An in vitro evaluation of marginal fit zirconia crowns fabricated by a CAD-CAM dental laboratory and a milling center.

BACKGROUND: Marginal fit is critical for the success and longevity of a dental restoration. Zirconia crowns can be fabricated either chair-side, in a dental laboratory or in a milling center; each can give different marginal fits results. However, discussion of the marginal fit of zirconia crowns when different fabrication methods are compared is lacking in the literature. PURPOSE: To compare the marginal discrepancy (MD) and absolute marginal discrepancy (AMD) of computer-aided design, and computer-aided manufacturing (CAD-CAM) used in a dental laboratory and a milling center for producing monolithic zirconia crowns. METHODS: The marginal fit of 30 zirconia crowns cemented to typodont teeth was evaluated by means of a sectioning technique. Fifteen crowns were fabricated with a CEREC inLAB MC X5 from IPS e.max ZirCAD blocks. Fifteen crowns were fabricated using a LAVA milling center from LAVA Plus Zirconia Blocks. The 30 crowns were sectioned with a precision saw, and MD and AMD were subsequently measured using a light microscope. Data were analyzed using the one-way ANOVA technique to investigate significant differences in the marginal fit between the two fabrication systems (α = .05). RESULTS: The AMD dimension of the CEREC inLAB system was significantly smaller (P < .05). Mean AMD values for zirconia crowns fabricated by the CEREC inLAB were 85 µm, and for the LAVA milling center 133 µm. There was no significant difference between the two systems regarding the MD dimensions. The MD values for zirconia crowns fabricated by the CEREC inLAB were 53 µm and for the LAVA milling center 61 µm. CONCLUSIONS: The CEREC inLAB system demonstrated significantly better marginal fit in relation to the AMD. However, no difference between the systems was found in the MD. Monolithic zirconia crowns fabricated by the CAD-CAM CEREC inLAB system and the LAVA system milling center showed MD values of less than 120 µm, which is within the clinically acceptable range.

[General strategy for the development of dental laboratories with CAD/CAM systems]. / Obshchaia strategiia razvitiia zubotekhnicheskikh laboratorii, osnashchennykh CAD/CAM-sistemami.

The need for the practice of dentistry in the digital (CAD/CAM) technologies have initiated the emergence of dental laboratories as a separate and independent legal entities. The choice of a strategy for the development of these laboratories is aimed at ensuring the achievement of the main goals in the long term. It is established that the type of innovation in terms of 'Shake test' J. Daya, in these organizations can be designated as an option 'C' - a strategy of gradual conquest of the market. The main components of the development are: work with staff, information support, financial optimization; material and technical support, marketing activities, organizational and legal support, the formation of the quality system.

Lean Methods Applied to CAD/CAM Pedagogy in the Dental Simulation Laboratory.

Dental education is incorporating computer-assisted design/computer-assisted manufacturing (CAD/CAM) into patient care delivery. The aim of this study was to determine if lean production methods applied to the preclinical phase of dental education would reduce the students' time (efficiency) to complete CAD/CAM indirect restorations (CAD/CAM IR) without compromising the desired quality of the CAD/CAM tooth preparations (effectiveness). In 2016, all third-year students at one U.S. dental school were randomly assigned to control and research groups (approximately 33 per group). The control group was taught using existing methods, while the course was redesigned to incorporate lean methods for the research group. Cycle times of the CAD/CAM IR process for both groups were collected and statistically analyzed to compare the effectiveness of the redesign. Standardized grading forms and tools were used to assess the quality of the CAD/CAM tooth preparations. The research group demonstrated significantly faster preparation times with both crowns and onlays (p<0.05) than the control group. The research group also produced CAD/CAM crown and onlay designs at a significantly faster pace than the control group (p<0.05). There was no significant difference between the control and research groups associated with the scanning process times (p>0.05) nor in the quality of the CAD/CAM tooth preparations (p>0.05). This study demonstrated that lean methods applied to pedagogy significantly decreased preparation and design times in a CAD/CAM restorative dentistry course without compromising the quality of the CAD/CAM tooth preparations.