Using digital technologies in concurrently performing missing tooth implantation and preparation of remaining teeth is a solution to reduce the number of visits and improve efficiency. This paper proposes a digital process for simultaneously implanting and preparing teeth. It integrates implant surgical guide and 3D-printed tooth preparation guide into a single guide and completes guided implant placement and precise tooth preparation. Based on "repair-oriented" virtual implant planning, the implant surgical guide can improve the efficiency and predictability of implant placement, and its linear accuracy is about 1 mm. The tooth preparation guide precisely guides tooth preparation and restoration space visualization, ensuring the quality of the tooth preparation. The two guides have different design accuracy requirements, and thus their combination improves the overall guiding accuracy requirements. The concurrent application of the two guides minimizes the clinical operation time, number of visits, and economic burden of patients.
Humans ; Surgery, Computer-Assisted ; Dental Implantation, Endosseous ; Printing, Three-Dimensional ; Technology ; Tooth Preparation ; Computer-Aided Design ; Dental Implants ; Imaging, Three-Dimensional ; Cone-Beam Computed Tomography

OBJECTIVE: To predict the learning curve of tooth preparation for all ceramic crowns of maxillary central incisors on phantom head simulators for graduate students participating in standardized dental resident training based on the modified Wright learning curve model, then to analyze and applicate the learning curve. METHODS: Twelve graduate students participating in standardized dental resident training were selected to prepare the resin maxillary central incisors on phantom head simulators for all ceramic crowns 4 times. The results of preparation were evaluated by 3 prosthetic experts with at least 10 years' experience focusing on the reduction, contour, taper, shoulder, finish line, margin placement, adjacent tooth injury, and preparation time for tooth preparation. The learning rate of tooth preparation was calculated by scores of tooth preparation of 4 times. The learning curve of tooth preparation was predicted based on the modified Wright learning curve model. According to the criteria of standardized training skill examinations for dental residents in Beijing, 80 was taken as the qualified standard score. The minimum training times for tooth preparation to satisfy the qualified standard score (80) was calculated, to analyze the characteristics of learning curve and evaluate the effectiveness of tooth preparation. RESULTS: The scores of 4 tooth preparation were 64.03±7.80, 71.40±6.13, 74.33±5.96, and 75.98±4.52, respectively. The learning rate was (106±4)%, which showed the learning curve an upward trend. There were no significant differences between the qualified standard score and the predicted scores of tooth preparation from the 5^th preparation to the 13^th preparation (P > 0.05). The predicted score of the 14^th preparation was higher than the qualified standard score (P < 0.05). CONCLUSION The trend of the learning curve of tooth preparation for all ceramic crowns of maxillary central incisors on phantom head simulators for graduate students participating in standardized dental resident training is upward, which predicts the minimum training times higher than the qualified standard score is 14 times.
Humans ; Tooth Preparation, Prosthodontic/methods* ; Incisor ; Learning Curve ; Crowns ; Tooth Preparation ; Ceramics ; Dental Porcelain ; Dental Prosthesis Design

In dental esthetic rehabilitation, patients pay great attention to the rehabilitative esthetic effect before teeth preparation, and this is also an important content of doctor-patient communication. Along with the development and combined application of intraoral scan, three-dimensional (3D) face scan, digital design, numerical control machining and 3D printing technology, digital technology is gradually applied to the virtual simulated design before irreversible operation in dental esthetic rehabilitation. Digital technology can be used in dentistry to simulate the esthetic outcome in advance, to assist communication among the dentists, patients and dental technicians, and to realize satisfactory outcome in the final restorations precisely, which, as a result, increases the clinical satisfaction. This review focuses on the application of digital virtual simulated design technology in dental esthetic rehabilitation, analyzes the current research development, deficiency and future prospects, so as to provide guidance for clinical diagnosis and treatment.
Computer-Aided Design ; Esthetics, Dental ; Face ; Humans ; Printing, Three-Dimensional ; Tooth Preparation

Tooth preparation is a common operation in dental clinical practice. This procedure is irreversible and invasive from the point of view of tooth preservation. Conditions of the abutment tooth, treatment methods, and restoration materials for target restoration affect tooth preparation. To achieve the goals of tooth tissue preservation, dental pulp protection, and periodontal health, dentistry professionals agreed on the importance of minimizing the amount of tooth reduction. The foundations for realizing this consensus are as follows. First, the available restoration materials with improved comprehensive performance need less target restoration space. Next, teeth can be prepared under a digital guide, and the real-time measurement of restoration space can be verified due to the invention of digital technologies for the analysis of the quantity and shape of the prepared tooth and tooth measurement. Moreover, guiding methods for preparation have been developed from freehand operation under the naked eye based on accumulated personal experience to digital-guidance jointing microscope. These innovations indicate the creation of a prototype of guided prosthodontics that is precise and applies real-time measurement throughout the process of tooth preparation. From the perspective of the evolution of digital, guided, and micro prosthodontics, this article raised seven questions about the numerical value and quantitative data transfer of tooth preparation and evaluated the authenticity of existing numerical requirements from the perspective of the four elements of measurement. Identifying unified measuring methods and developing measuring tools with a precision of hundred or ten microns will be the key to solving the problem about the authenticity of numerical measurement. Furthermore, this paper summarizes the methods of how to control tooth reduction and explains in depth why the currently dominant tooth preparation technology, which is based on empiricism, cannot effectively achieve the goals in digital prosthodontics. Therefore, we strongly call for rebuilding the digital foundation of prosthodontic treatment immediately.
Prosthodontics ; Tooth ; Tooth Preparation

Tooth preparation is the primary and core operation technique for prosthodontics. Microscopic tooth preparation can improve the accuracy and efficiency of the operation. Experts from Society of Prosthodontics, Chinese Stomatological Association formulated the standard operating procedure for microscopic tooth preparation, so as to standardize its design points and operating procedures, highlight the difference between this novel technique and the traditional naked eye tooth preparation and promote the application of microscopic tooth preparation.
Asian Continental Ancestry Group ; Humans ; Oral Medicine ; Prosthodontics ; Reference Standards ; Tooth Preparation

The minimum amount of tooth preparation that can be fully controlled is crucial in achieving long-term, stable, and effective aesthetic restoration, which is also a major difficulty in aesthetic restoration. The tooth preparation can be imple-mented efficiently and accurately through digital technology based on the fixed-deep hole guiding technology. Prior the actual tooth preparation, the technology first designs the virtual contour, layering, and virtual occlusion of the prosthesis on the computer. Then, virtual tooth preparation is carried out by cutting back according to the virtual prosthesis. Next, the virtual drilling operation plan is designed according to the shape of the virtual tooth preparation and the contour of the abutment tooth. Finally, the tooth preparation guide plate is designed and printed in 3D. It realizes the whole process of quantitative and precise guidance of dental preparation, visualizes the restoration space, reduces the clinical operation time, and guarantees the quality of dental preparation. It also promotes the improvement of the teaching quality of digital practical exercises.
Bone Plates ; Esthetics, Dental ; Printing, Three-Dimensional ; Tooth ; Tooth Preparation

A clear shoulder platform that can be easily identified by doctors and technicians or machines (mouth scan and warehouse scan) is important to obtaining a good long-term and stable fixed prosthesis treatment effect. At present, the pre-paration of the shoulder platform is usually based on free hands, and the practical operation is mainly guided by experience. Moreover, no comprehensive and objective preoperative design, intraoperative verification, and final test are available. Thus, the accuracy of shoulder platform preparation needs to be improved. In this study, the clinical pathway of "three determination, three selection, and three steps" with high accuracy of preparation and the precise shoulder preparation method of "bur-tip guidance" are proposed in detail.
Critical Pathways ; Shoulder ; Tooth ; Tooth Preparation ; Tooth Preparation, Prosthodontic

OBJECTIVE: To set up near-field microwave detection system, to evaluate the accuracy of measuring water and to compare the effects of different methods on drying root canal. METHODS: Known and quantitative distilled water in Eppendorf tube and root canal was detected by near-field microwave detection system which was set up first. The microwave reflection coefficient was recorded so as to evaluate the accuracy of the measuring water. 12 single-rooted mandibular premolar teeth with apical matureness and a curvature less than 10° were decoronated, leaving roots 14 mm in length. After instrumentation to F3, the root canals were air-dried and injected with 10 μL distilled water each. Then all the root canals were assigned to 4 groups (n=12) according to different methods on root canal drying. Near-field microwave detection system was used to detect the change of water after air-drying and root canal drying so as to evaluate the effects of different root canal drying methods: (1) negative control group, the canals were injected with 10 μL distilled water and no root canal drying method was performed; (2) paper points drying experimental group, four #60 paper points were used to blot-dry the middle and upper part of the canal, followed by #40 paper points blot-drying the apical area. The above step was repeated with the tip of paper point that appeared with no water under microscope as finished; (3) 95% (volume fraction) ethanol drying experimental group, after the distilled water was removed with paper points (similar to paper points experimental group), 10 μL 95% ethanol was injected into the canal and was left in place for 10 s, then paper points were used to dry the canal; (4) 70% (volume fraction) isopropyl alcohol drying experimental group, after the distilled water was removed with paper points (similar to paper points experimental group), 10 μL 70% isopropyl alcohol was injected into the canal and was left in place for 10 s, then paper points were used to dry the canal. The linear correlation analysis was used to test the accuracy of the measuring water by near-field microwave detection method and physical measurement. The Pearson correlation coefficient was calculated based on the data. The effects of different methods on drying root canal were analyzed by Chi square test. RESULTS: The R2 for the microwave reflection coefficient and the physical measurement of the water in Eppendorf tube and root canal were 0.991 and 0.970. The microwave reflection coefficient in all the experimental groups showed significant difference (P<0.05). After drying with paper points, the residual water was the most, and the microwave reflection coefficient was the highest: 0.023. While after 70% isopropyl alcohol drying root canal, the residual water was the least with the microwave reflection coefficient 0.006, showing that the effect of drying was the best. CONCLUSION Near-field microwave detection system could detect the change of water in root canal. The effect of root canal drying by 70% isopropyl alcohol was superior to 95% ethanol and paper points.
Dental Pulp Cavity ; Desiccation ; Microwaves ; Root Canal Preparation ; Root Canal Therapy ; Tooth Root

OBJECTIVES: It was the aim of this study to evaluate the effect of cooling water temperature on the temperature changes in the pulp chamber and at the handpiece head during high-speed tooth preparation using an electric handpiece. MATERIALS AND METHODS: Twenty-eight intact human molars received a standardized occlusal preparation for 60 seconds using a diamond bur in an electric handpiece, and one of four treatments were applied that varied in the temperature of cooling water applied (control, with no cooling water, 10°C, 23°C, and 35°C). The temperature changes in the pulp chamber and at the handpiece head were recorded using K-type thermocouples connected to a digital thermometer. RESULTS: The average temperature changes within the pulp chamber and at the handpiece head during preparation increased substantially when no cooling water was applied (6.8°C and 11.0°C, respectively), but decreased significantly when cooling water was added. The most substantial drop in temperature occurred with 10°C water (−16.3°C and −10.2ºC), but reductions were also seen at 23°C (−8.6°C and −4.9°C). With 35°C cooling water, temperatures increased slightly, but still remained lower than the no cooling water group (1.6°C and 6.7ºC). CONCLUSIONS: The temperature changes in the pulp chamber and at the handpiece head were above harmful thresholds when tooth preparation was performed without cooling water. However, cooling water of all temperatures prevented harmful critical temperature changes even though water at 35°C raised temperatures slightly above baseline.
Burns ; Dental Instruments ; Dental Pulp Cavity ; Head ; Humans ; Molar ; Thermometers ; Tooth Preparation ; Tooth ; Water

Tooth preparation is the primary and core operation technique for dental esthetic restoration treatment, due to its effect of providing restoration space, bonding interfaces and marginal lines for dental rehabilitation after tooth tissue reduction. The concept of microscopic minimal invasive dentistry put forward the issue of conducting high-quality tooth preparation, conserve tooth-structure, protect vital pulp and periodontal tissue simultaneously. This study reviewed the concepts, physiology background, design and minimal invasive microscopic tooth preparation, and in the meantime, individualized strategies and the two core elements of tooth preparation (quantity and shape) are listed.
Dental Porcelain ; Dental Restoration, Permanent ; Esthetics, Dental ; Tooth Preparation