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1.
Hua Xi Kou Qiang Yi Xue Za Zhi ; 38(6): 712-717, 2020 Dec 01.
Artículo en Chino | MEDLINE | ID: mdl-33377353

RESUMEN

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.


Asunto(s)
Preparación del Diente , Diente , Vías Clínicas , Hombro , Preparación Protodóncica del Diente
2.
Zhonghua Kou Qiang Yi Xue Za Zhi ; 55(10): 710-715, 2020 Oct 09.
Artículo en Chino | MEDLINE | ID: mdl-33045780

RESUMEN

Accurate and measurable tooth preparation under the principle of protecting dental tissue, vital pulp and periodontal tissue health is a challenging procedure in esthetic dental restoration. The traditional protocol of tooth preparation often leads to complications after restoration because of the lack of precise preparation control. The pre-operative analysis and design, intraoperative guidance and sequence guidance technology of post-operative prosthesis production, with the target restoration space (TRS) as the core and digital technology as the support technology, embody the numerical requirements of the prosthesis space based on the actual measurement, and will lay the core foundation of the future digital prosthodontics. This paper introduces the new understanding of tooth preparation guidance, the classification and application of digital guides, the practice of micro tooth preparation guided by digital template, and summarizes the development direction of prosthodontics from experience guidance to digital guidance.


Asunto(s)
Estética Dental , Preparación del Diente , Pulpa Dental , Periodoncio , Prostodoncia
3.
Chin J Dent Res ; 23(3): 183-189, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32974618

RESUMEN

OBJECTIVE: To design and fabricate 3D-printed rigid constraint guides for the tooth preparation for laminate veneers and to evaluate the accuracy of guide-assisted preparation. METHODS: Twenty maxillary right central incisor resin artificial teeth were randomly divided into two equal groups and prepared for laminate veneers. Tooth preparations were performed, assisted by guides in the test group and by depth gauge burs in the control group, and both were finished by freehand operation. The typodonts were 3D scanned before preparation, after initial preparation and after final preparation. The tooth preparation depths at each step, including initial preparation depth, final preparation depth and loss of tooth tissue during polishing, were measured by 3D deviation analysis. Statistical analyses were conducted to investigate differences. RESULTS: The initial preparation depth was 0.488 mm (median, quartile 0.013 mm) in the test group and 0.521 mm (median, quartile 0.013 mm) in the control group. A statistically significant difference was found between them (P < 0.05). The final preparation depth in the test group (0.547 ± 0.029 mm) was significantly less than that in the control group (0.599 ± 0.051 mm) (P < 0.05), and closer to the predesigned value (0.5 mm). There was no statistically significant difference in the loss of tooth tissue during polishing between the test group (0.072 ± 0.023 mm) and the control group (0.089 ± 0.038 mm) (P > 0.05). CONCLUSION: In maxillary central incisors, the tooth preparation for laminate veneers could be conducted using 3D-printed rigid constraint guides, the accuracy of which is better than that of depth gauge burs.


Asunto(s)
Porcelana Dental , Coronas con Frente Estético , Incisivo , Rayos Láser , Preparación del Diente
4.
Hua Xi Kou Qiang Yi Xue Za Zhi ; 38(3): 350-355, 2020 Jun 01.
Artículo en Chino | MEDLINE | ID: mdl-32573148

RESUMEN

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.


Asunto(s)
Estética Dental , Diente , Placas Óseas , Impresión Tridimensional , Preparación del Diente
5.
Minerva Stomatol ; 69(1): 21-26, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-32181608

RESUMEN

BACKGROUND: Ultrasonic devices have a lot of dental application specially in hygiene and surgery. However there are some disadvantages like cut slowness and heat production. Prosthodontics application is less investigated. In particular the heat production could be an important factor for the clinician. In fact more than 5.5 °C temperature increasing could determine pulp necrosis during tooth preparation. The aim of this study is to investigate the increasing of temperature during finishing line repositioning and polishing phases using ultrasounds inserts and to verify if it remains within the limit of 5.5 °C. METHODS: A sample of 32 human molars (extracted for periodontal reasons) was selected. The teeth were endodontically treated and prepared with burs in order to obtain a prosthetic round chamfer preparation, leaving the apical portion pervious for inserting the thermocouple probe. Then, they were inserted in plaster cubes up to the cement-enamel junction. A wall has been selected for each tooth for margin repositioning and finishing and prepared with the piezoelectric instrument (Multipiezo Touch with TipHolder DB2, Mectron, Carasco, Genoa, Italy). A mechanical arm was used to standardize the operator-dependent parameters. These parameters were: the pressure exerted on the dental wall, the cutting length and the time required for margin repositioning and finishing. The test phase consisted in a first stage of margin repositioning using an regular ultrasound tip with a diamond grain of 120 micron (DB120, Mectron, Carasco, Italy) (group 1), followed by a second finishing step conducted by a extra fine ultrasound tip with a diamond grain of 60 micron (DB60, Mectron, Carasco, Italy) (group 2). Each test lasted 60 seconds: this was the time that the mechanical arm needed to accomplish 32 rides. During these stages the intrapulpal temperature has been recorded thanks to a thermocouple. The obtained temperature data were analyzed by Kruskal-Wallis test and Mann-Withney post-hoc test, without Bonferroni correction (P<0.001). RESULTS: The average pulpal temperature increase was 4.65 °C with a standard deviation of 0.99 °C for the DB 120 ultrasonic tip and 5.40 °C with a standard deviation of 0.84 °C for the DB 60 ultrasonic tip. However, neither of the instruments reach the medium critical level of 5.5°C reported in the literature, there are some single values who exceed it. There is statistically significant difference using tips with different granulometries within the two groups (P value =0.013). CONCLUSIONS: Ultrasonic tools are very performing to achieve results in repositioning and polishing of prepared tooth. The in-vitro analysis show that the pulp temperature increasing remains within the safe limits literature shows. It is important underline the polishing phase is the most critical and the clinicians have to pay attention to irrigation and pression to avoid pulp damages. Additional clinical studies have to be performed to confirm these results.


Asunto(s)
Pulpa Dental , Preparación del Diente , Esmalte Dental , Materiales Dentales , Humanos , Italia
7.
J Appl Oral Sci ; 28: e20190145, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32049132

RESUMEN

OBJECTIVE: Ultrasonic wave technology is widely used during dental treatments. We previously demonstrated that this method protects the gingival tissue. However, the physiological change on the gingival microvasculature caused by this method remains unclear. The aim of this study was to investigate the relationship between the morphological and physiological effects on gingival microcirculation when preparing teeth, using the conventional dental turbine or ultrasonic method. METHODOLOGY: The lower premolar teeth of beagle dogs were prepared along the gingival margin by using a dental turbine or ultrasonic wave instrument. Gingival vasculature changes were investigated using scanning electron microscopy for corrosion resin casts. Gingival blood flow at the preparation site was determined simultaneously by laser Doppler flowmetry. These assessments were performed immediately (Day 0), at 7 days and 30 days after tooth preparation. RESULTS: At day 0, in the turbine group, blood vessels were destroyed and some resin leaked. Furthermore, gingival blood flow at the site was significantly increased. In contrast, the ultrasonic group demonstrated nearly normal vasculature and gingival blood flow similar to the non-prepared group for 30 days after preparation. No significant alterations occurred in gingival circulation 30 days after either preparation; however, the turbine group revealed obvious morphological changes. CONCLUSIONS: Based on multiple approach analyses, this study demonstrated that ultrasonic waves are useful for microvascular protection in tooth preparation. Compared with a dental turbine, ultrasonic wave instruments caused minimal damage to gingival microcirculation. Tooth preparation using ultrasonic wave instruments could be valuable for protecting periodontal tissue.


Asunto(s)
Encía/irrigación sanguínea , Microcirculación/fisiología , Preparación del Diente/instrumentación , Ondas Ultrasónicas , Animales , Protocolos Clínicos , Instrumentos Dentales , Perros , Femenino , Humanos , Flujometría por Láser-Doppler/métodos , Microscopía Electrónica de Rastreo , Reproducibilidad de los Resultados , Factores de Tiempo , Preparación del Diente/métodos
8.
J Esthet Restor Dent ; 32(2): 150-160, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-32031329

RESUMEN

OBJECTIVE: The ability to control the reduction of tooth structure in a precise and measurable way during the preparation of ceramic veneers is a clinical challenge. The objective of this article is to introduce a new digital technology that can be used to address this challenge showing its advantages and limitations. First Fit is a digitally guided tooth preparation system that can be used to control the accurate and efficient preparation of teeth. In some cases, the system can be used to prepare the teeth for previously made restorations based on planned digital reduction. CLINICAL CONSIDERATIONS: The First Fit system uses 3D-printed guides and a specially designed handpiece for guided veneer preparation using either a one-step or a two-step approach. In the one-step approach, final restorations are produced prior to preparation of the teeth using reduction guides, and veneers are cemented on the same day as preparation. The two-step approach includes a preparation phase during which the teeth are prepared using a combination of the reduction guides and free hand techniques. Cementation is then completed at a second appointment. CONCLUSION: The First Fit system controls and guides veneer preparation with a minimally invasive approach. In some cases, it enables the production of veneers before tooth preparation, alleviating the need for provisional restorations. CLINICAL SIGNIFICANCE: The guided restorative dentistry technique described here utilizes digital CAD-CAM technology to achieve predictable and accurate results in a minimally invasive and efficient manner.


Asunto(s)
Coronas con Frente Estético , Preparación del Diente , Cerámica , Diseño Asistido por Computadora , Porcelana Dental
9.
J Esthet Restor Dent ; 32(6): 554-559, 2020 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-31925892

RESUMEN

OBJECTIVE: The aim of this study was to determine the effects of preparation vs nonpreparation of tooth surfaces and the types of porcelain laminate veneers (PLVs) on color changes after 300 hours of artificially accelerated aging (AAA). MATERIALS AND METHODS: Forty extracted maxillary central incisors were used. The teeth were divided into four groups (n = 10) to evaluate preparation methods and porcelain types: Group A: tooth preparation with IPS e.max computer-assisted design (CAD), group B: tooth preparation with IPS e.max press, group C: nonpreparation with IPS e.max CAD, and group D: nonpreparation with IPS e.max press. Veneers were fabricated and cemented using a dual-polimerized cement. Initial color measurement was performed and repeated after AAA. Color changes were calculated with the CIEDE 2000 (ΔE00 ) formula. Color differences were analyzed with two-way ANOVA (P < .05). RESULTS: The two-way ANOVA test showed no significant difference among the groups (P > .05). The highest color change value was observed in group C, followed by groups B, A, and D. CONCLUSION: Preparation of veneers caused more color changes in PLVs than nonpreparation. However, IPS e.max CAD systems for fabrication of nonprepared PLVs increased the color change of the PLVs measured after AAA. CLINICAL SIGNIFICANCE: The results provide information on the effect of the amount of preparation and the type of porcelain on color change in porcelain laminate veneers. In terms of esthetic dentistry, IPS e.max press and non-prep treatment should be used in the anterior region, where esthetics are important.


Asunto(s)
Porcelana Dental , Coronas con Frente Estético , Color , Diseño Asistido por Computadora , Incisivo , Ensayo de Materiales , Preparación del Diente
10.
J Prosthodont ; 29(3): 201-206, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-31994818

RESUMEN

PURPOSE: To evaluate the accuracy of two intraoral scanners (IOS) in terms of different preparation designs and scan angulation limitation due to the presence of adjacent teeth. MATERIALS AND METHODS: Eight different complete coverage (CC) and partial coverage (PC) tooth preparations were scanned by two IOS, the 3Shape TRIOS (TRI) and the 3M True Definition (TRU). All teeth preparations were scanned in the presence and absence of adjacent teeth. Four groups were established for each IOS; Group 1: PC preparations with adjacent teeth. Group 2: CC preparations with adjacent teeth. Group 3: PC preparations without adjacent teeth. Group 4: CC preparations without adjacent teeth. 3D analysis was performed to examine average absolute discrepancy (AAD) and maximum absolute discrepancy (MAD). A Two-way ANOVA was performed followed by a post-hoc Tukey's test HSD to evaluate the effect of adjacent teeth, preparation design, and the type of IOS used. RESULTS: For TRI, AAD for groups 1, 2, 3, and 4 were 20 ± 1.8 µm, 19.6 ± 2.4 µm, 15.5 ± 2.7 µm, and 12.9 ± 1.4 µm, respectively, whereas MAD for groups 1, 2, 3, and 4 were 109.7 ± 13.5 µm, 93.2 ± 28.9 µm, 85.6 ± 16.1 µm, and 66 ± 20.1 µm, respectively. For TRU IOS, AAD for groups 1, 2, 3, and 4 were 22.0 ± 3.6 µm, 17.9 ± 2 µm, 20 ± 5.9 µm, and 14.9 ± 1.7 µm, respectively, whereas the MAD for groups 1, 2, 3, and 4 were 151.4 ± 38.4 µm, 92.2 ± 17. µm, 92.6 ± 23.6 µm, and 71.4 ± 11.9 µm, respectively. Two-way ANOVA showed statistically significant differences between the AAD and MAD of TRI and TRU (p < 0.001). There were also statistically significant differences for presence or absence of adjacent teeth (p < 0.001), and preparation design (p < 0.001). CONCLUSIONS: PC preparation scans revealed lower accuracy than CC. The presence of adjacent teeth decreased the accuracy of both IOS. TRI gave higher accuracy than TRU for PC, but both IOS showed comparable accuracy for CC groups.


Asunto(s)
Técnica de Impresión Dental , Modelos Dentales , Diseño Asistido por Computadora , Arco Dental , Imagenología Tridimensional , Preparación del Diente
11.
Minerva Stomatol ; 69(1): 14-20, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-31633318

RESUMEN

BACKGROUND: The purpose of this study was to analyze pulpal temperature increase generated by prosthodontic margin repositioning and finishing with ultrasonic and rotating instruments. The temperature changes recorded were also correlated with the residual dentin thickness. METHODS: A sample of 32 human extracted molars was selected. The teeth were endodontically treated and prepared with prosthetic round chamfer preparation. Then, they were inserted in plaster cubes up to the cement-enamel junction, leaving the apical portion pervious for inserting the thermocouple probe. The conventional technique, which involves the use of a high-speed contra-angle handpiece, was compared with an ultrasonic method (Crown Prep, Mectron, Carasco, Italy). For margin repositioning and finishing, two walls were randomly selected for each tooth: one was included in the test group and cut with the piezoelectric instrument (Multipiezo Touch TipHolder DB2, Mectron, Carasco, Genoa, Italy), the other one was inserted in the control group and cut with the high speed contra-angle handpiece (Kavo, Biberach, Germany). To standardize the operator-dependent parameters, it was used a mechanical arm controlled by a computer. These parameters were the pressure exerted on the dental wall, the cutting length and the time required for margin repositioning and finishing. For both test and control group, test phase consisted in a first stage of margin repositioning using an ultrasound tip or a diamond bur with a greater granulometry (120 µm for the ultrasound tip and 125 µm for the diamond bur), followed by a second finishing step conducted by an ultrasound tip or a diamond bur with smaller granulometry (60 µm for the ultrasound tip and 30 µm for the diamond bur). During these stages the intrapulpal temperature was recorded thanks to a thermocouple. Before and after these steps, the thickness of the remaining dental walls was measured with a caliber. RESULTS: The average pulpal temperature increase was 5.03±0.98 °C for the ultrasonic preparation (test group) and 3.55±0.95 °C for the conventional technique (control group). The difference was statistically significant (P value <0.001). However, neither of the instruments reached the critical level of 5.5 °C reported in the literature. The mean initial dentin thicknesses was 1.82±0.47 mm for the control group and 1.59±0.54 mm for the test group but the analysis of the residual dentin thicknesses revealed a greater reduction of the walls worked up with high speed contra-angle handpiece (mean 0.9±0.5 mm), which was therefore more aggressive than the ultrasonic instrument (mean 1.1±0.5 mm). A very weak negative correlation was present between the thickness of the wall at baseline and the increment of temperature. CONCLUSIONS: Within limitations of this study, temperature increasing of ultrasonic instruments shows a statistical difference related to rotary ones. But, as literature shows, the ultrasonic advantages are margin precision, preservation of soft tissues and reduction of operating times. Furthermore, in relation with results of this study, they could be considered safe for pulp vitality because the increase in pulpal temperature is similar to traditional instruments and it does not exceed the critical level of 5.5 °C.


Asunto(s)
Cavidad Pulpar , Preparación del Diente , Dentina , Humanos , Italia , Temperatura
12.
J Prosthet Dent ; 123(1): 20-26, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31079881

RESUMEN

The recent evolution of digital technologies in dentistry has enabled virtual 3D diagnostic analysis of a dentition before treatment, allowing for virtual, minimally invasive treatment planning. In this report, an extensively worn dentition was 3D virtual analyzed at an increased vertical dimension of occlusion. Virtual waxing (exocad DentalCAD; Exocad) and subsequent analysis of the need for minimally invasive preparations were performed. Areas of each tooth without adequate clearance for the minimal thickness of a definitive restoration (set at 1.5 mm in the software), including the amount of tooth substance to be removed (GOM Inspect; GOM), were visualized in color. A preparation guide was virtually designed according to this diagnostic plan (3-matic; Materialise) and 3D printed (Connex3 Objet260; Stratasys) from resin (VeroMagenta RGD851; Stratasys). The teeth were minimally prepared using the guide, and the amount of preparation was validated by superimposing the scan of the prepared model on the initial scan and comparing it with the diagnostic plan.


Asunto(s)
Atrición Dental , Desgaste de los Dientes , Humanos , Preparación del Diente , Dimensión Vertical , Flujo de Trabajo
13.
J Prosthet Dent ; 124(1): 88-93, 2020 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-31672425

RESUMEN

STATEMENT OF PROBLEM: Although different preparation designs have been proposed for onlays fabricated by computer-aided design and computer-aided manufacturing (CAD-CAM), their effect on marginal adaptation is unclear. PURPOSE: The purpose of this in vitro study was to investigate the effect of tooth preparation designs on the marginal and internal adaptation of ceramic-reinforced composite resin CAD-CAM onlays. MATERIAL AND METHODS: A traditional preparation with a heavy chamfer on the functional cusp and a contrabevel on the nonfunctional cusp and a shoulder preparation with equal reduction on all cusps were used for mesial-occlusal-distal (MOD) onlay preparations. Ceramic-reinforced composite resin onlays were designed and milled based on the scanned prepared teeth. A digital silicone replica technique was used to determine marginal discrepancies between preparations and onlay restorations. A total of 100 numeric distances (representations of the fit in each region) were measured in 3 distinct regions: the buccal margin, lingual margin, and internal area. Independent Student t tests were used to determine significant differences (α=.05). RESULTS: Traditional preparation designs resulted in significantly smaller overall discrepancies (50.9 ±0.5 µm and 139.1 ±5.4 µm, P<.001) and smaller marginal discrepancies in the buccal (49.7 ±1.4 µm and 135.8 ±2.2 µm, P<.001) and lingual areas (47.1 ±1.0 µm and 133.4 ±1.1 µm, P<.001). CONCLUSIONS: The marginal adaptation of ceramic-reinforced composite resin CAD-CAM onlays was affected by the preparation design. The traditional preparation design offered better marginal adaptation; therefore, it is recommended in clinical practice.


Asunto(s)
Adaptación Marginal Dental , Incrustaciones , Resinas Compuestas , Diseño Asistido por Computadora , Coronas , Diseño de Prótesis Dental , Humanos , Preparación del Diente
14.
Oper Dent ; 45(3): 229-234, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-31860390

RESUMEN

Bonding to enamel has been shown to provide reliable results, and thus conservative tooth preparations are key to the success of ceramic bonded restorations. The wax-up is the first diagnostic tool available to evaluate discrepancies between current and ideal tooth proportions. The clinician's diagnostic mock-up provides the patient with a visual perception of the size and shape of the proposed restorations. The use of reduction guides assists the restorative dentist in evaluating the specific amount of tooth structure to be removed during preparation. Furthermore, total isolation with a rubber dam prior to bonding the final restorations is crucial for the success of adhesive protocols. The aim of this report is to demonstrate a conservative approach to tooth preparation with a complete isolation technique prior to bonding eight ceramic restorations.


Asunto(s)
Cerámica , Recubrimiento Dental Adhesivo , Esmalte Dental , Porcelana Dental , Coronas con Frente Estético , Humanos , Preparación del Diente
15.
J Am Dent Assoc ; 151(2): 127-135, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-31883705

RESUMEN

BACKGROUND: The authors evaluated the local accuracy of intraoral scanning (IOS) systems for single-tooth preparation impressions with an in vitro setup. METHODS: The authors digitized a mandibular complete-arch model with 2 full-contour crowns and 2 multisurface inlay preparations with a highly accurate reference scanner. Teeth were made from zirconia-reinforced glass ceramic material to simulate toothlike optical behavior. Impressions were obtained either conventionally (PRESIDENT, Coltène) or digitally using the IOS systems TRIOS 3 and TRIOS 3 using insane scan speed mode (3Shape), Medit i500, Version 1.2.1 (Medit), iTero Element 2, Version 1.7 (Align Technology), CS 3600, Version 3.1.0 (Carestream Dental), CEREC Omnicam, Version 4.6.1, CEREC Omnicam, Version 5.0.0, and Primescan (Dentsply Sirona). Impressions were repeated 10 times per test group. Conventional (CO) impressions were poured with type IV gypsum and digitized with a laboratory scanner. The authors evaluated trueness and precision for preparation margin (MA) and preparation surface (SU) using 3-dimensional superimposition and 3-dimensional difference analysis method using (95% - 5%) / 2 percentile values. Statistical analysis was performed using Kruskal-Wallis test. Results were presented as median (interquartile range) values in micrometers. RESULTS: The authors found statistically significant differences for MA and SU among different test groups for both trueness and precision (P < .05). Median (interquartile range) trueness values ranged from 11.8 (2.0) µm (CO) up to 40.5 (10.9) µm (CEREC Omnicam, Version 5.0.0) for SU parameter and from 17.7 (2.6) µm (CO) up to 55.9 (15.5) µm (CEREC Omnicam, Version 5.0.0) for MA parameter. CONCLUSIONS: IOS systems differ in terms of local accuracy. Preparation MA had higher deviations compared with preparation SU for all test groups. PRACTICAL IMPLICATIONS: Trueness and precision values for both MA and SU of single-unit preparations are equal or close to CO impression for several IOS systems.


Asunto(s)
Técnica de Impresión Dental , Modelos Dentales , Diseño Asistido por Computadora , Arco Dental , Imagenología Tridimensional , Preparación del Diente
16.
Int J Comput Dent ; 23(4): 351-362, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33491931

RESUMEN

This article introduces a new, fully digital workflow for the preparation of a guiding template and the procedure of the clinical operation in which it is put to use. A step-by-step technique is described including the virtual CAD of the preparation, the design of the template, the restoration based on the contours of the virtual preparation, the tooth preparation guided by the template, and the bonding of the predesigned restoration. The design and manufacture of all the templates and restorations are completed before the clinical operation.


Asunto(s)
Computadores , Preparación del Diente , Diseño Asistido por Computadora , Humanos , Flujo de Trabajo
17.
Int J Comput Dent ; 22(4): 331-342, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31840141

RESUMEN

AIM: Precise tooth preparation is necessary for successful restorative treatments. In the narrow oral space, achieving such precision with traditional manual operation is impeded by visual deviation, human eye blind zones, and hand-orientation errors. To overcome these drawbacks, a mini-robotic system for tooth preparation was developed to manipulate an ultra-short-pulse laser beam for the automatic shaping of a target tooth into a prepared tooth. Automatic tooth preparation is based on three-dimensional (3D) data. The present study was conducted to investigate the basic principles for digitally designing full crown tooth preparations and to quantitatively evaluate the associated design precision. MATERIALS AND METHODS: Cone beam computed tomography (CBCT) and dental model surface scan data were obtained from 20 volunteers. Using these data, a complete and systematic process for the digital design of full crown tooth preparations was conducted. The study included 40 cases with two design types. Software-derived measurements of prepared occlusal thickness, shoulder width, and axial convergence angle were compared with the design preparation data. RESULTS: The design precision for shoulder width exceeded that for occlusal ablation depth, which exceeded that for axial convergence angle. One-way ANOVA analysis results confirmed no significant differences in the design precision of full crown preparations with different tooth morphologies, and the independent samples t test results showed no significant difference among the design standards. The mean errors for occlusal ablation depth, shoulder width, and axial convergence angle were 0.0096 ± 0.0108 mm, 0.0006 ± 0.0004 mm, and 0.1201 ± 0.1288 degrees, respectively. CONCLUSION: The design route of the full crown computer-aided design (CAD) software reported on in this article is highly feasible and accurate.


Asunto(s)
Coronas , Diente , Diseño Asistido por Computadora , Modelos Dentales , Diseño de Prótesis Dental , Humanos , Preparación del Diente
18.
Prim Dent J ; 8(3): 48-63, 2019 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-31666173

RESUMEN

The provision of indirect restorations utilising contemporary materials for single or multiple abutment units in primary health care is an essential requirement for all general dental practitioners to ensure predictable patient outcomes. This paper highlights the important considerations for comprehensive planning and adept treatment execution and delivery that can enhance the patient's dental experience and outcome. A selection of clinical cases highlighting established and novel restorative materials utilising conventional and adhesive clinical techniques is presented and discussed.


Asunto(s)
Cementación , Materiales Dentales , Prostodoncia , Preparación del Diente/métodos , Adhesivos , Humanos , Satisfacción del Paciente , Resultado del Tratamiento
19.
Int J Oral Sci ; 11(3): 31, 2019 10 02.
Artículo en Inglés | MEDLINE | ID: mdl-31575850

RESUMEN

By removing a part of the structure, the tooth preparation provides restorative space, bonding surface, and finish line for various restorations on abutment. Preparation technique plays critical role in achieving the optimal result of tooth preparation. With successful application of microscope in endodontics for >30 years, there is a full expectation of microscopic dentistry. However, as relatively little progress has been made in the application of microscopic dentistry in prosthodontics, the following assumptions have been proposed: Is it suitable to choose the tooth preparation technique under the naked eye in the microscopic vision? Is there a more accurate preparation technology intended for the microscope? To obtain long-term stable therapeutic effects, is it much easier to achieve maximum tooth preservation and retinal protection and maintain periodontal tissue and oral function health under microscopic vision? Whether the microscopic prosthodontics is a gimmick or a breakthrough in obtaining an ideal tooth preparation should be resolved in microscopic tooth preparation. This article attempts to illustrate the concept, core elements, and indications of microscopic minimally invasive tooth preparation, physiological basis of dental pulp, periodontium and functions involved in tool preparation, position ergonomics and visual basis for dentists, comparison of tooth preparation by naked eyes and a microscope, and comparison of different designs of microscopic minimally invasive tooth preparation techniques. Furthermore, a clinical protocol for microscopic minimally invasive tooth preparation based on target restorative space guide plate has been put forward and new insights on the quantity and shape of microscopic minimally invasive tooth preparation has been provided.


Asunto(s)
Estética Dental , Preparación del Diente , Consenso
20.
Int J Prosthodont ; 32(5): 444-447, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31486817

RESUMEN

Fixed dental prostheses are the standard treatment option for replacing missing teeth when adjacent teeth require crowns or are already restored with crowns. Divergent abutment teeth axes may require invasive teeth preparation to achieve a common path of insertion, which substantially weakens residual tooth structure and increases the risk of pulpal problems. In selected cases with divergent abutment teeth in the buccal-lingual direction, the use of a rotational path of insertion might overcome these problems. This concept is presented via a clinical case history report.


Asunto(s)
Dentadura Parcial Fija , Pérdida de Diente , Coronas , Pilares Dentales , Humanos , Preparación del Diente
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