scholarly journals Transferring the tooth preparation finish line on intraoral digital scans to dental software programs: A dental technique

2022 ◽  
Author(s):  
Guillermo Cabanes-Gumbau ◽  
Juan Carlos Palma ◽  
John C. Kois ◽  
Marta Revilla-León
Keyword(s):  
Finish Line ◽  
Tooth Preparation ◽  
Software Programs

scholarly journals Marginal and internal fit and intaglio surface trueness of interim crowns fabricated from tooth preparation of four finish line locations

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Keunbada Son ◽  
Young-Tak Son ◽  
Ji-Min Lee ◽  
Kyu-Bok Lee
Keyword(s):  
Three Dimensional ◽  
Clinical Situation ◽  
Intraoral Scanner ◽  
Replica Technique ◽  
Finish Line ◽  
Marginal Fit ◽  
Tooth Preparation ◽  
The Right ◽  
Internal Fit ◽  
Marginal Region

AbstractThis study evaluated the marginal and internal fit and intaglio surface trueness of interim crowns fabricated from tooth preparation scanned at four finish line locations. The right maxillary first molar tooth preparation model was fabricated using a ceramic material and placed in four finish line locations (supragingival, equigingival, subgingival, and subgingival with a cord). Intraoral scanning was performed. Crowns were designed based on the scanned area. Interim crowns were fabricated using a stereolithography three-dimensional (3D) printer (N = 16 per location). Marginal and internal fit were evaluated with a silicone replica technique. Intaglio surface trueness was evaluated using a 3D inspection software. One-way analysis of variance and Tukey HSD test were performed for comparisons (α = 0.05). The marginal and internal fit showed significant differences according to locations (P < 0.05); the marginal fit showed the best results in the supragingival finish line (P < 0.05). Intaglio surface trueness was significantly different in the marginal region, with the highest value in the subgingival location (P < 0.05). Crowns fabricated on the subgingival finish line caused inaccurate marginal fit due to poor fabrication reproducibility of the marginal region. The use of an intraoral scanner should be decided on the clinical situation and needs.

scholarly journals Minimal invasive microscopic tooth preparation in esthetic restoration: a specialist consensus

2019 ◽  
Vol 11 (3) ◽  
Author(s):  
Haiyang Yu ◽  
Yuwei Zhao ◽  
Junying Li ◽  
Tian Luo ◽  
Jing Gao ◽  
...  
Keyword(s):  
Minimally Invasive ◽  
Critical Role ◽  
Minimal Invasive ◽  
Therapeutic Effects ◽  
Preparation Technique ◽  
Finish Line ◽  
Physiological Basis ◽  
Core Elements ◽  
Tooth Preparation

Abstract 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.

Effect of the Crown Preparation Margin and Die Type on the Marginal Accuracy of Fiber-reinforced Composite Crowns

2008 ◽  
Vol 9 (2) ◽  
pp. 9-16 ◽  
Author(s):  
Mohamed F. Ayad
Keyword(s):  
Epoxy Resin ◽  
Finish Line ◽  
Fiber Reinforced Composite ◽  
Reinforced Composite ◽  
Measuring Microscope ◽  
Significant Difference ◽  
Die Material ◽  
Tooth Preparation ◽  
The Difference ◽  
Crown Preparation

Abstract Aim The objective of this laboratory investigation was to determine the effect of different preparation designs (light chamfer, deep chamfer, and shoulder) and die-making materials (stone and epoxy) on the resulting margin misfit for fiber-reinforced composite crowns using a measuring microscope. Methods and Materials Sixty standardized FibreKor crowns were made on stone and epoxy resin dies (n=30 each) duplicated from three metal master dies representing complete crown tooth preparation with a total convergence of 5°. For each die group, three of the tooth preparation designs were established in relation to the type of finish line (n=0 each) as follows: Group A (0.5-mm light chamfer finish line); Group B (1.0-mm deep chamfer finish line); and Group C (1.0-mm shoulder finish line). Marginal accuracy was evaluated by measuring the distances between each of four pairs of indentations on the crowns and on the dies with a Nikon measuring microscope. Results Analysis of seating measurements with parametric analysis of variance and Tukey's Studentized Range (HSD) disclosed a statistically significant difference for both tooth preparation design and die material (p< 0.001). However, the interaction effect was not significant (p=0.9073). The least marginal opening value was for FibreKor crowns made on epoxy resin dies with a light chamfer finish line (57 μm), but the difference was not statistically significantly different from crowns made on epoxy resin dies with a deep chamfer light chamfer finish line (61 μm). However, crowns made on epoxy resin dies with a shoulder finish line (81 μm) had significantly higher values (p< 0.05). FibreKor crowns made on stone dies with the shoulder finish line (95 μm) had statistically higher marginal opening values (p< 0.05). The least marginal opening value was for crowns made on stone dies with a light chamfer finish line (66 μm), but the difference was not statistically significantly different from crowns made on stone dies with a deep chamfer light chamfer finish line (70 μm). Conclusions Significant differences were found among the die material used for the shoulder margin design. However, there was no significant difference between light chamfer and deep chamfer margin designs for both die materials. Citation Ayad MF. Effect of the Crown Preparation Margin and Die Type on the Marginal Accuracy of Fiberreinforced Composite Crowns. J Contemp Dent Pract 2008 February;(9)2:009-016.

scholarly journals Effect of Different Software Programs on the Accuracy of Dental Scanner Using Three-Dimensional Analysis

2021 ◽  
Vol 18 (16) ◽  
pp. 8449
Author(s):  
Keunbada Son ◽  
Wan-Sun Lee ◽  
Kyu-Bok Lee
Keyword(s):  
Reference Model ◽  
Three Dimensional ◽  
In Vitro Study ◽  
3D Analysis ◽  
Analysis Software ◽  
Test Models ◽  
Significant Difference ◽  
Tooth Preparation ◽  
Software Programs

This in vitro study aimed to evaluate the 3D analysis for complete arch, half arch, and tooth preparation region by using four analysis software programs. The CAD reference model (CRM; N = 1 per region) and CAD test models (CTMs; N = 20 per software) of complete arch, half arch, and tooth preparation were obtained by using scanners. For both CRM and CTMs, mesh data other than the same area were deleted. For 3D analysis, four analysis software programs (Geomagic control X, GOM Inspect, Cloudcompare, and Materialise 3-matic) were used in the alignment of CRM and CTMs as well as in the 3D comparison. Root mean square (RMS) was regarded as the result of the 3D comparison. One-way analysis of variance and Tukey honestly significant difference tests were performed for statistical comparison of four analysis software programs (α = 0.05). In half-arch and tooth preparation region, the four analysis software programs showed a significant difference in RMS values (p < 0.001), but in complete-arch region, no significant difference was found among the four software programs (p = 0.139). As the area of the virtual cast for 3D analysis becomes smaller, variable results are obtained depending on the software program used, and the difference in results among software programs are not considered in the 3D analysis for complete-arch region.

scholarly journals Different Types of Finish Lines, Gingival Retraction Methods and Impression Techniques Used During Single Crown Preparation

2020 ◽  
Vol 11 (SPL3) ◽  
pp. 1192-1201
Author(s):  
Ahmed Hilal Sheriff K ◽  
Nivedhitha M S ◽  
Rakshagan V
Keyword(s):  
Statistical Significance ◽  
Daily Routine ◽  
Chi Square ◽  
Finish Line ◽  
Impression Technique ◽  
Single Crown ◽  
Chi Square Test ◽  
Tooth Preparation ◽  
Crown Preparation ◽  
University Setting

Tooth preparation is part of the daily routine for dentists. Each step involved in the tooth preparation is important. This study focuses on three parameters, finish lines, retraction methods and impression technique. retraction and impression technique go hand in hand, as retraction of the is mandatory to expose the prepared finish line and record them accurately. This study aimed to determine various types of finish lines, retraction methods and impression techniques incorporated during single crown preparation in Saveetha Dental College and Hospitals. Case records were collected from DIAS (Dental Information Archiving Software). This university setting study involved a sample size of 812 patients. Data was tabulated with parameters of name, age, sex, finish line, retraction, no. of cords, type of impression. The retraction method used was a mechanical retraction method which comprised 794 teeth and 554 of the retraction was done using &quot;2 cords (000+1)&quot;. 2 stage putty wash technique was commonly employed during impression taking in tooth preparation of 746 teeth. Chi-square test done for association between tooth and finish lines, retraction methods, no. of cords used and impression technique did not show any statistical significance (p&gt;0.05) while association of finish line with no. of cords and type of impression showed statistical significance (p&lt;0.05). Within the limit of the study, the most widely used finish line was shoulder finish line and mechanical retraction methods were commonly employed with 2 stage putty wash technique being the most common impression technique.

scholarly journals Effect of Finish Line on Marginal Fit of Sintered Gold Copings

2013 ◽  
Vol 24 (4) ◽  
pp. 322-325
Author(s):  
Fernanda Pelogia Gwinner ◽  
Marco Antonio Bottino ◽  
Lafayete Nogueira-Junior ◽  
Alvaro Della Bona
Keyword(s):  
Marginal Gap ◽  
Finish Line ◽  
Marginal Fit ◽  
Metal Ceramic ◽  
Ceramic Crowns ◽  
Master Model ◽  
Tooth Preparation ◽  
Student’S T ◽  
Equidistant Points ◽  
Student’S T Test

The aim of this study was to evaluate the vertical marginal gap of sintered gold copings and metal-ceramic crowns with different finish line preparations: a beveled round shoulder (BRS) and a beveled long chamfer (BLC), testing the null hypotheses that there are no differences in marginal gap regardless of finish line and phase of restoration (coping or crown). Stainless steel master models were fabricated to simulate tooth preparation for metal-ceramic crowns with different finish lines (BRS and BLC). Ten dies were obtained from each model. Preparations were coated with 2 layers of spacer to 1 mm from the margin. Sintercast gold copings were prepared, sintered and adjusted to the dies. The copings (n=10) were placed onto the master model and the marginal gap was measured in 24 equidistant points using optical microscopy (X230). An opaque and two body ceramic layers were subsequently applied to the copings and the same measuring procedure was performed for the crowns. The data were analyzed statistically using paired and unpaired Student's t-test (α=0.05). Mean marginal gap values (µm) for the copings and crowns were, respectively: 113.6 and 117.1 for the BRS; and 58.2 and 74.3 for the BLC preparation. Significantly greater marginal gaps (p=0.0307) were found for restorations with BRS than with BLC finish line, which also showed statistically significant differences in the gap size between coping and crown (p=0.001). In conclusion, marginal gap is influenced by ceramic application on copings fabricated on BLC preparation, and greater marginal gaps were found for restorations with BRS finish line, rejecting the experimental null hypotheses.

scholarly journals Assessment of Tooth Preparations Submitted to Dental Laboratories for Fabrication of Monolithic Zirconia Crowns

2021 ◽  
Vol 9 (10) ◽  
pp. 112
Author(s):  
Ramtin Sadid-Zadeh ◽  
Hadjer Sahraoui ◽  
Brian Lawson ◽  
Robert Cox
Keyword(s):  
Three Dimensional ◽  
Finish Line ◽  
Posterior Teeth ◽  
3D Images ◽  
Line Angle ◽  
Zirconia Crowns ◽  
Monolithic Zirconia ◽  
Tooth Preparation ◽  
Line Design

Purpose: The objective of this study was to assess the quality of posterior teeth prepared for monolithic zirconia crowns. Materials and Methods: A total of 392 STL-files of posterior preparations for monolithic zirconia crowns were evaluated in this study. Three-dimensional (3D) images were evaluated using a software (3D Viewer; 3Shape A/S, Copenhagen, Denmark) for finish line design, finish line width, occluso-cervical dimension, total occlusal convergence (TOC), intercuspal angulation, finish line quality, line angle form, and presence or absence of undercut at the axial wall and unsupported lip of enamel. The assessment was performed by two calibrated evaluators. Then, data were descriptively analyzed. Data for occluso-cervical dimension and TOC were descriptively analyzed according to their location. Results: Thirty-nine percent of premolars, 77% of first molars, and 91% of second molars had an average occluso-cervical dimension of less than 3 mm (premolars) and 4 mm (molars), with most of the preparations having a TOC of more than 20 degrees. More than 50% of preparations had undercut, unsupported enamel and/or unacceptable finish line quality. Conclusions: The quality of tooth preparation including finish line quality, absence of unsupported enamel and undercut at the axial wall should be evaluated when preparing monolithic zirconia crowns.

scholarly journals Assessment and evaluation of errors in tooth preparation by undergraduate students: an institution based in-vitro study

2020 ◽  
Author(s):  
Jyothsna Krishnamurthy ◽  
K. Bharanija ◽  
Krishna Reddy ◽  
H. Annapoorni
Keyword(s):  
Undergraduate Students ◽  
Dental Students ◽  
Tooth Surface ◽  
Clinical Expertise ◽  
Finish Line ◽  
Impression Material ◽  
All Ceramic ◽  
Tooth Preparation ◽  
Jaw Model

Aim: To assess the errors made during preclinical tooth preparation by the undergraduate students of Meenakshi Ammal Dental College and Hospital, Chennai. Objectives: To understand the reason, nature and frequency of the errors occurring during tooth preparation done by undergraduate dental students during their preclinical practice. Materials and Methods: A total of hundred samples were collected from the undergraduate students. All the samples were upper right central incisors (11) typodont teeth, prepared to receive an All-ceramic crown. All the samples were prepared by mounting the typodont (NISSIN Typodont Jaw Model) on a phantom head simulator. All the preparations were made as freehand preparations. The following aspects of the preparation were evaluated: 1. Facial and palatal reduction 2. Occlusal clearance 3. Finish line width The evaluation of all the three aspects was done by studying a cross-section of an impression made on the prepared tooth. The impressions were made using a hard splint, which was fabricated on the typodont jaw model, prior to tooth preparation, as an impression tray. The impression material used was Light body(Zhermack Elite HD – Light normal set) impression material Results: The measurements and values obtained were subjected to statistical analysis to obtain the final result. Regarding the amount of prepared tooth surface, the frequency of errors encountered was more with regard to palatal reduction. Regarding the width of the finish line, Labial aspect of the finish line was most commonly under prepared. Conclusion: Within the limitations of the study, the main recommendation is to increase the pre-clinical practice time to emphasise more on the clinical expertise and the importance of proper operator positioning during tooth preparation. Key Words:Tooth preparation, All-ceramic restorations, Errors

scholarly journals Marginal and internal fit and intaglio surface trueness of interim crowns fabricated from tooth preparation of four finish line locations

2021 ◽  
Author(s):  
Keunbada Son ◽  
Young-Tak Son ◽  
Ji-Min Lee ◽  
Kyu-Bok Lee
Keyword(s):  
Three Dimensional ◽  
3D Printer ◽  
Intraoral Scanner ◽  
Replica Technique ◽  
Finish Line ◽  
Marginal Fit ◽  
Tooth Preparation ◽  
The Right ◽  
Internal Fit ◽  
Marginal Region

Abstract This study evaluated the marginal and internal fit and intaglio surface trueness of interim crowns fabricated from tooth preparation scanned at four finish line locations. The right maxillary first molar tooth preparation model was fabricated using a ceramic material and placed in four finish line locations (supragingival, equigingival, subgingival, and subgingival with a cord). Intraoral scanning was performed. Crowns were designed based on the scanned area. Interim crowns were fabricated using a stereolithography three-dimensional (3D) printer (N = 16 per location). Marginal and internal fit were evaluated with a silicone replica technique. Intaglio surface trueness was evaluated using a 3D inspection software. One-way analysis of variance and Tukey HSD test were performed for comparisons (α = 0.05). The marginal and internal fit showed significant differences according to locations (P < 0.05); the marginal fit showed the best results in the supragingival finish line (P < 0.05). Intaglio surface trueness was significantly different in the marginal region, with the highest value in the subgingival location (P < 0.05). Crowns fabricated on the subgingival finish line caused inaccurate marginal fit due to poor fabrication reproducibility of the marginal region. A supragingival finish line is recommended for interim crown fabrication using an intraoral scanner.

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