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Makakova DR, Alexandrov S, Vlahova A. Comparative analysis of tensile strength between three types of retraction cords. Folia Med (Plovdiv) 2023; 65:447-452. [PMID: 38351821 DOI: 10.3897/folmed.65.e83093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Accepted: 06/10/2022] [Indexed: 02/16/2024] Open
Abstract
INTRODUCTION Gingival retraction is the withdrawal of the marginal gingiva away from the tooth. This procedure creates a space between the prepared tooth and the gingival tissues to catch more fine details of the impression material. The most common retraction device used in clinical practice is the retraction cord.
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Gracis S, Llobell A, Chu SJ. Contemporary concepts on periodontal complications from prosthetic and restorative therapies. Periodontol 2000 2023; 92:159-196. [PMID: 37466152 DOI: 10.1111/prd.12505] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2022] [Revised: 06/01/2023] [Accepted: 06/05/2023] [Indexed: 07/20/2023]
Abstract
The clinical outcome of every prosthetic and restorative procedure depends on the maintenance of a healthy periodontium. It is, therefore, important that the prosthodontist and restorative dentist cause no harm or permanent damage to the underlying hard and soft tissues when performing clinical procedures necessary to carry out the planned treatment. Several factors involved in these procedures have been described to have an impact on gingival health. For the present article, a selection of four of these factors are presented with the goal of evaluating the current trends and their influence on periodontal structures: (1) tooth preparation configuration and apical extension, (2) gingival tissue sulcular expansion/retraction, (3) prosthetic contours, and (4) prosthesis marginal adaptation and the consequences of excess cement remnants. Based on the available scientific evidence and clinical experience, recommendations for the practitioner are given.
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Affiliation(s)
| | - Arturo Llobell
- Private Practice, Valencia, Spain
- Division of Restorative Dentistry, University of Pennsylvania, School of Dental Medicine, Philadelphia, Pennsylvania, USA
| | - Stephen J Chu
- Ashman Department of Periodontology and Implant Dentistry, Department of Prosthodontics, New York University College of Dentistry, New York, New York, USA
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Mills DA, Fountain AC, Velazquez D. Cord Placement Model: An Instructional Guide for Preclinical Dental Students to Practice the Skill of Retraction Cord Placement. MEDEDPORTAL : THE JOURNAL OF TEACHING AND LEARNING RESOURCES 2023; 19:11303. [PMID: 36866189 PMCID: PMC9971216 DOI: 10.15766/mep_2374-8265.11303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Accepted: 11/21/2022] [Indexed: 06/18/2023]
Abstract
INTRODUCTION Gingival displacement is essential for ideal margin exposure and improved direct or indirect restorative outcome. Recent literature found many dentists prefer using retraction cord. Some contraindications of other displacement methods make retraction cord displacement preferred. It is necessary to teach dental students appropriate cord placement while minimizing gingival trauma. METHODS We developed a stone model using prepared typodont teeth and simulated gingiva that was made of polyvinylsiloxane material. Twenty-three faculty and 143 D2 students were briefed on the instructional guide. After faculty demonstration, D2 students practiced for 10-15 minutes under observation. The following year, former D2 (now D3) and D4 students were asked for feedback on the instructional experience. RESULTS Fifty-six percent of faculty rated the model and instructional guide good to excellent, and 65% rated the student experience as good to excellent, with only one participant rating it poor. Seventy-eight percent of D3 students strongly agreed or agreed the exercise increased their understanding of the technique in placing cord on a patient. Furthermore, 94% of D4 students strongly agreed or agreed having this exercise in preclinical D2 year would have been helpful. DISCUSSION Use of retraction cord to deflect gingiva is still preferred by most dentists. Completing the cord placement exercise on a model helps prepare students to perform the procedure on a patient before arriving at the clinic. Survey comments such as "useful exercise" support use of this instructional model. Overall, faculty and D3 and D4 students felt the exercise was beneficial to use in preclinical education.
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Affiliation(s)
- Denise Amelia Mills
- Associate Professor and Clinical Care Coordinator, Midwestern University College of Dental Medicine-Arizona
| | - Anita Chu Fountain
- Assistant Professor and Clinical Care Faculty, Midwestern University College of Dental Medicine-Arizona
| | - Daphne Velazquez
- Assistant Professor and Preclinical Faculty, Midwestern University College of Dental Medicine-Arizona
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Biological Response Induced in Primary Human Gingival Fibroblasts upon Exposure to Various Types of Injectable Astringent Retraction Agents. MATERIALS 2021; 14:ma14082081. [PMID: 33924145 PMCID: PMC8074361 DOI: 10.3390/ma14082081] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 04/16/2021] [Accepted: 04/18/2021] [Indexed: 12/30/2022]
Abstract
Traditional chemo-mechanical retraction/displacement materials can impact the gingival margin tissues. This study was undertaken to analyze biological responses induced in human gingival fibroblasts (HGFs) upon application of injectable astringent-based agents used in the cordless retraction technique. HGFs were exposed to hemostatic agents (five gels, three pastes, and one foam) based on aluminium chloride, aluminium sulphate and ferric sulphate. Changes in cell viability and proliferation were evaluated using an MTT assay and a BrdU assay. The cytoskeleton structure organization (zyxin and F-actin) was visualized by confocal laser scanning microscopy. Oxidative stress was determined using the Griess Reagent System. The RNA expression levels of antioxidant enzymes were quantified by real-time RT-PCR. The statistical significance was evaluated using Student’s t-test and one-way ANOVA with post-hoc Tukey HSD test. The evaluated agents did not downregulate fibroblast viability or proliferation. No significant cytoskeleton reorganization was observed. Only one agent (Expasyl) induced oxidative stress, demonstrated by the increased level of nitrites. Incubation with the studied agents significantly increased the RNA expression of some antioxidant enzymes (SOD1, SOD3, GPX1). However, no significant influence on the expression of SOD2 and HMOX1 was detected. The injectable forms of chemical retraction agents revealed biocompatibility with HGFs, suggesting their potential clinical usefulness in gingival margin retraction.
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Ercoli C, Tarnow D, Poggio CE, Tsigarida A, Ferrari M, Caton JG, Chochlidakis K. The Relationships Between Tooth-Supported Fixed Dental Prostheses and Restorations and the Periodontium. J Prosthodont 2020; 30:305-317. [PMID: 33210761 DOI: 10.1111/jopr.13292] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/16/2020] [Indexed: 12/19/2022] Open
Abstract
PURPOSE To search the literature and to critically evaluate the findings on the periodontal outcomes of restorations and tooth-supported fixed prostheses. MATERIALS AND METHODS PubMed was searched according to a systematic methodology, previously reported, but updated to include a larger database. Filters applied were: Case reports, clinical trial, review, guideline, randomized controlled trial, meta-analysis, systematic reviews, and English. A narrative review was then synthesized to discuss periodontal outcomes related to restorations and tooth-supported fixed prostheses. Relevant data was organized into four sections: Direct restorations, indirect restorations, biologic width or supracrestal tissue attachment and tooth preparation/finish line design. RESULTS While increased gingival index, bleeding on probing, probing depth and clinical attachment loss have been associated with subgingival restorations, intracrevicular margins do not cause periodontal diseases. Inflammation and bone loss occur, for both direct and indirect restorations, only with large overhangs. Different restorative materials are associated with different clinical responses when placed in the gingival sulcus or within the epithelial and connective tissue attachments. When the connective tissue attachment is removed, histological changes occur causing its apical shift and subsequent re-establishment. Gingival displacement during impression procedures can cause gingival recession. Emergence profile can have a range of values, not associated with periodontal diseases. Periodontal response appears to be clinically not different when compared among different finish line designs. CONCLUSIONS Contemporary procedures and materials used for the placement and fabrication of tooth-supported restorations and fixed prostheses are compatible with periodontal health when adequate patient education and motivation in self-performed oral hygiene are present. Periodontal diagnostic criteria should be thoroughly reviewed before fixed restorative treatments are planned and executed.
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Affiliation(s)
- Carlo Ercoli
- Departments of Prosthodontics and Periodontics, Eastman Institute for Oral Health, University of Rochester, Rochester, NY
| | - Dennis Tarnow
- Department of Periodontics, Columbia University College of Dentistry, New York, NY
| | - Carlo E Poggio
- Departments of Prosthodontics and Periodontics, Eastman Institute for Oral Health, University of Rochester, Rochester, NY
| | - Alexandra Tsigarida
- Departments of Prosthodontics and Periodontics, Eastman Institute for Oral Health, University of Rochester, Rochester, NY
| | - Marco Ferrari
- Department of Medical Biotechnologies, Division of Fixed Prosthodontics, Dean, University of Siena, Siena, Italy
| | - Jack G Caton
- Departments of Prosthodontics and Periodontics, Eastman Institute for Oral Health, University of Rochester, Rochester, NY
| | - Konstantinos Chochlidakis
- Departments of Prosthodontics and Periodontics, Eastman Institute for Oral Health, University of Rochester, Rochester, NY
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Clinical acceptance of single-unit crowns and its association with impression and tissue displacement techniques: Findings from the National Dental Practice-Based Research Network. J Prosthet Dent 2019; 123:701-709. [PMID: 31590974 DOI: 10.1016/j.prosdent.2019.05.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2018] [Revised: 05/06/2019] [Accepted: 05/22/2019] [Indexed: 11/21/2022]
Abstract
STATEMENT OF PROBLEM The definitive impression for a single-unit crown involves many material and technique factors that may affect the success of the crown. PURPOSE The purpose of this prospective cohort study was to determine whether impression technique (tray selection), impression material, or tissue displacement technique are associated with the clinical acceptability of the crown (CAC). MATERIAL AND METHODS Dentists in the National Dental Practice-Based Research Network documented details of the preparation, impression, and delivery of 3730 consecutive single-unit crowns. Mixed-effects logistic regression analyses were performed to evaluate associations between impression techniques and materials and the CAC and to assess associations between the presence of a subgingival margin with the displacement technique and the outcome variables CAC and number of impressions required. RESULTS Of the 3730 crowns, 3589 (96.2%) were deemed clinically acceptable. A significant difference in the CAC was found with different impression techniques (P<.001) and different impression materials (P<.001). The percentage of the CAC for digital scans was 99.5%, 95.8% for dual-arch trays, 95.2% for quadrant trays, and 94.0% for complete-arch impression trays. Although no statistically significant difference was found in the CAC produced with dual-arch trays without both mesial and distal contacts, crowns fabricated under these conditions were less likely to achieve excellent occlusion. The percentage of the CAC for digital scans was 99.5%, 97.0% for polyether impressions, 95.5% for polyvinyl siloxane impressions, and 90.5% for other impression materials. Accounting for the location of the margin, the use of a dual-cord displacement technique was significantly associated with lower rates of requiring more than 1 impression (P=.015, odds ratio=1.43). CONCLUSIONS Dual-arch trays produced clinically acceptable crowns; however, if the prepared tooth was unbounded, the occlusal fit was more likely to have been compromised. Digital scans produced a slightly higher rate of CAC than conventional impression materials. The use of a dual-cord technique was associated with a decreased need to remake impressions when the margins were subgingival.
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Schmitz JH, Valenti M. Interim restoration technique for gingival displacement with a feather-edge preparation design and digital scan. J Prosthet Dent 2019; 123:580-583. [PMID: 31375275 DOI: 10.1016/j.prosdent.2019.04.020] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Revised: 04/18/2019] [Accepted: 04/19/2019] [Indexed: 11/24/2022]
Abstract
A straightforward and time-efficient technique is presented for recording digital scans in single- and multiple-unit tooth abutments with feather-edge finish lines. The margins of the interim restoration should be precise and sufficiently deep in the sulcus so that the tissues can be properly displaced. Definitive intraoral scans should be made approximately 3 to 4 weeks after the tooth (or teeth) has been prepared to allow healing of the soft tissues. The interim restoration is first removed and then reseated after removing cement residue. First, a scan is made with the interim restoration in place. The abutment tooth or teeth are then erased from the original digital file, the interim restoration is removed again, and a new scan enclosing only the abutment tooth is made.
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Dederichs M, Fahmy MD, Kuepper H, Guentsch A. Comparison of Gingival Retraction Materials Using a New Gingival Sulcus Model. J Prosthodont 2019; 28:784-789. [PMID: 31206914 DOI: 10.1111/jopr.13093] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/08/2019] [Indexed: 11/30/2022] Open
Abstract
PURPOSE To investigate the pressure generated by different retraction materials using a novel gingival sulcus model. MATERIALS AND METHODS A gingival sulcus model was made using a polymer frame filled with silicon. A pressure sensor and a sulcus-fluid simulation were embedded into the silicon chamber to evaluate the pressure generated by different retraction materials. Six sizes of Ultrapak retraction cords (Ultradent, sizes #000 - 3), 4 retraction pastes (Expazen, Expasyl, Acteon, Access Edge, Traxodent) and 2 retraction gels (Sulcus Blue, Racegel) were analyzed. The mean and median pressure, interquartile range, and standard deviation (SD) of n = 10 repeated measurements were calculated. Statistical analysis was conducted by Kruskal-Wallis test for differences between the main groups of retraction materials, and Mann-Whitney U-test was performed to analyze differences between the single retraction materials. RESULTS Pressure (mean ± SD) generated by retraction cords increased with increasing size (48.26 ± 11.29 kPa, size #000 to 149.27 ± 28.75 kPa for #3). There was a significant difference between sizes (p < 0.01), except in #0 versus #1, and #2 versus #3. Retraction pastes generated pressures that ranged from 82.74 ± 29.29 kPa (Traxodent) to 524.35 ± 113.88 kPa (Expasyl). Retraction gels generated pressures from 38.96 ± 14.68 kPa (Racegel) to 95.15 ± 24.18 kPa (Sulcus Blue). Pressure generated by Expasyl was significantly higher than pressure generated by all other tested materials (p < 0.001). CONCLUSION Pressure generated by retraction pastes and gels depends on the consistency of the retraction material, while pressure generated by retraction cords increased with increasing size of cords. Expasyl was found to generate the highest pressure compared to all other retraction materials.
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Affiliation(s)
- Marco Dederichs
- Policlinic of Prosthetic Dentistry and Material Science, Centre for Dental Medicine, Jena University Hospital, Jena, Germany
| | - Mina D Fahmy
- Department of Oral and Maxillofacial Surgery, University of Tennessee Medical Center, Knoxville, TN
| | - Harald Kuepper
- Policlinic of Prosthetic Dentistry and Material Science, Centre for Dental Medicine, Jena University Hospital, Jena, Germany
| | - Arndt Guentsch
- Department of Surgical Sciences, School of Dentistry, Marquette University, Milwaukee, WI
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Abstract
Dental impression making is the process of creating a negative form of the teeth and oral tissues, into which gypsum or other die materials can be processed to create working analogues. Contemporary dentistry generates new information every year and digital dentistry is becoming established and influential. Although dentists should stay abreast of new technologies, some of the conventional materials and time-tested techniques remain widely used. It is important to review the impression-making process to ensure that practitioners have up-to-date information about how to safely and effectively capture the exact form of the oral tissues to provide optimal patient management.
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Affiliation(s)
- Amit Punj
- Department of Restorative Dentistry, OHSU School of Dentistry, 2730 Southwest Moody Avenue, Room 10N078, Portland, OR 97201, USA.
| | - Despoina Bompolaki
- Department of Restorative Dentistry, OHSU School of Dentistry, 2730 Southwest Moody Avenue, Room 10N076, Portland, OR 97201, USA
| | - Jorge Garaicoa
- Department of Restorative Dentistry, OHSU School of Dentistry, 2730 Southwest Moody Avenue, Room 10N076, Portland, OR 97201, USA
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Einarsdottir ER, Lang NP, Aspelund T, Pjetursson BE. A multicenter randomized, controlled clinical trial comparing the use of displacement cords, an aluminum chloride paste, and a combination of paste and cords for tissue displacement. J Prosthet Dent 2017; 119:82-88. [PMID: 28478985 DOI: 10.1016/j.prosdent.2017.03.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2016] [Revised: 03/08/2017] [Accepted: 03/09/2017] [Indexed: 10/19/2022]
Abstract
STATEMENT OF PROBLEM Gingival recession after soft tissue displacement for impression making in fixed prosthodontics may pose a problem for treatment success in the esthetic areas of the mouth. Knowledge about the soft tissue reaction of common gingival displacement methods is limited. PURPOSE The purpose of this clinical randomized controlled trial (RCT) was to evaluate changes in the marginal soft tissue height with 3 different gingival tissue displacement techniques for definitive impression making of natural teeth. MATERIAL AND METHODS A total of 67 individuals were randomized to 3 groups. In test group 1 (P; n=22), only aluminum chloride paste was used to displace the gingiva. In test group 2 (CP; n=23), a cord was inserted, and aluminum chloride paste was also used. In the control group (C; n=22), 2 cords were used to displace the gingiva (double-cord technique). Clinical measurements of the gingival position were made before treatment began and at 30 ±10 days after prosthesis delivery. Study casts were fabricated at different stages of the treatment, standardized photographs were made, and changes in the buccal gingival position were measured using graphics editing software. In addition, the participants' perception of the clinical procedure and the technicians' evaluation of the die preparation were recorded. One-way ANOVA models were applied to compare the response variables among the groups: (a) the position of the gingival margin (millimeters), (b) mean probing pocket depth (millimeters), (c) gingival thickness (millimeters), (d) amount of keratinized tissue (millimeters), and (e) mean changes in gingival margin height (millimeters). Unpaired t tests were also used to compare the mean values between groups. For comparisons between different categories, chi-square tests were performed (α=.05 for all tests). RESULTS In the period between impression and delivery, a minor gain in gingival height of 0.058 mm (±0.13 SD) for P and 0.013 mm (±1.19 SD) for CP. However, a minor gingival recession of 0.049 mm (±0.13 SD) was reported for group C. The results for all groups showed that 21% of abutment teeth gained >0.1 mm in gingival height, 58% had stable gingival height (0 ±0.10 mm), 21% showed minor gingival recession (0.1 to 0.5 mm), and no abutment teeth showed moderate or severe gingival recession (>0.5 mm). The incidence of minor gingival recession was 8% in group P, 23% in group CP, and 32% in group C (P=.015). Fifteen participants (24%) experienced some discomfort after the procedure. The differences between the groups were not significant (P>.05). The laboratory technicians found the definitive die preparation significantly more challenging for group P (visual analog scale [VAS], 79) and CP (VAS, 82) than group C (mean VAS, 93; P=.003). CONCLUSIONS Minor or moderate gingival recession (<1 mm) is more likely to occur when conventional cords are used during impression making. However, the laboratory technicians found the die preparation significantly less challenging when the double-cord technique was used than when impressions were made using the paste displacement technique.
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Affiliation(s)
- Erna R Einarsdottir
- Instructor, Division of Reconstructive Dentistry, Faculty of Odontology, University of Iceland, Reykjavik, Iceland.
| | - Niklaus P Lang
- Professor Emeritus, University of Berne, Berne, Switzerland; and Professor Emeritus, University of Zurich, Zurich, Switzerland
| | - Thor Aspelund
- Professor, Center of Public Health Sciences, Faculty of Medicine, University of Iceland, Reykjavik, Iceland
| | - Bjarni E Pjetursson
- Professor, Division of Reconstructive Dentistry, Faculty of Odontology, University of Iceland, Reykjavik, Iceland
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McCracken MS, Louis DR, Litaker MS, Minyé HM, Oates T, Gordan VV, Marshall DG, Meyerowitz C, Gilbert GH. Impression Techniques Used for Single-Unit Crowns: Findings from the National Dental Practice-Based Research Network. J Prosthodont 2017; 27:722-732. [PMID: 28076661 DOI: 10.1111/jopr.12577] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/28/2016] [Indexed: 12/01/2022] Open
Abstract
PURPOSE To: (1) determine which impression and gingival displacement techniques practitioners use for single-unit crowns on natural teeth; and (2) test whether certain dentist and practice characteristics are significantly associated with the use of these techniques. MATERIALS AND METHODS Dentists participating in the National Dental Practice-Based Research Network were eligible for this survey study. The study used a questionnaire developed by clinicians, statisticians, laboratory technicians, and survey experts. The questionnaire was pretested via cognitive interviewing with a regionally diverse group of practitioners. The survey included questions regarding gingival displacement and impression techniques. Survey responses were compared by dentist and practice characteristics using ANOVA. RESULTS The response rate was 1777 of 2132 eligible dentists (83%). Regarding gingival displacement, most clinicians reported using either a single cord (35%) or dual cord (35%) technique. About 16% of respondents preferred an injectable retraction technique. For making impressions, the most frequently used techniques and materials are: poly(vinyl siloxane), 77%; polyether, 12%; optical/digital, 9%. A dental auxiliary or assistant made the final impression 2% of the time. Regarding dual-arch impression trays, 23% of practitioners report they typically use a metal frame tray, 60% use a plastic frame, and 16% do not use a dual-arch tray. Clinicians using optical impression techniques were more likely to be private practice owners or associates. CONCLUSIONS This study documents current techniques for gingival displacement and making impressions for crowns. Certain dentist and practice characteristics are significantly associated with these techniques.
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Affiliation(s)
- Michael S McCracken
- Department of Clinical and Community Sciences, School of Dentistry, University of Alabama at Birmingham, Birmingham, AL
| | - David R Louis
- Private practice of general dentistry with HealthPartners, Woodbury, MN
| | - Mark S Litaker
- Department of Clinical and Community Sciences, School of Dentistry, University of Alabama at Birmingham, Birmingham, AL
| | - Helena M Minyé
- Private practice of general dentistry, Odessa and Fort Worth, TX
| | - Thomas Oates
- School of Dentistry, University of Texas Health Science Center at San Antonio, San Antonio, TX
| | - Valeria V Gordan
- Restorative Dental Sciences Department, Operative Dentistry Division, College of Dentistry, University of Florida, Gainesville, FL
| | | | - Cyril Meyerowitz
- Eastman Institute for Oral Health, University of Rochester, Rochester, NY
| | - Gregg H Gilbert
- Department of Clinical and Community Sciences, School of Dentistry, University of Alabama at Birmingham, Birmingham, AL
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- The National Dental PBRN Collaborative Group includes practitioner, faculty, and staff investigators who contributed to this activity
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Cai H, Yang S, Pei X, Qing H, Wang J. Practice-based preclinical instruction for gingival displacement with animal models. J Prosthet Dent 2016; 117:405-409. [PMID: 27677218 DOI: 10.1016/j.prosdent.2016.07.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Revised: 07/13/2016] [Accepted: 07/14/2016] [Indexed: 10/20/2022]
Abstract
STATEMENT OF PROBLEM Gingival displacement is recognized as a substantive and difficult procedure in fixed prosthodontics. However, a realistic simulation of gingival displacement is unavailable for preclinical dental students. PURPOSE The purpose of this study was to evaluate whether practice-based preclinical instruction of gingival displacement with animal models could improve students' skill in patient care. MATERIAL AND METHODS Isolated bovine mandibles (calves were younger than 6 months of age) and isolated porcine hemimandibles were prepared for this study. Twenty-two general dental practitioners with at least 5 years of experience were randomly selected and assigned to perform gingival displacement on both bovine and porcine jaws. Those practitioners were then asked to assess the clinical similarity of gingival displacement between human teeth and animal teeth. The data were analyzed with the paired t test (α=.05). Upon confirmation that the animal jaw provided a similar gingival displacement environment to that of human teeth, 80 predoctoral dental students were enrolled and randomized into 2 groups. Half of them underwent the new practice-based instruction, while the others underwent traditional preclinical teaching only (lectures, online video, or live demonstration). After preclinical learning, clinical performance in gingival displacement was evaluated for all students in terms of the effect of gingival displacement and quality of impression. The data were analyzed with the chi-square test (α=.05). RESULTS The dentogingival environments of porcine and bovine jaws were similar to those of human jaws, and no significant difference was detected between these 2 animal models (P=.178). A significant increase occurred in the acceptable rate of the effect of gingival displacement (P<.001) and the quality of impression (P<.001) among students who received the practice-based instruction compared with those who received traditional teaching. CONCLUSIONS These findings suggest that this practice-based instruction of gingival displacement with animal models is an effective method of promoting dental students' learning of gingival displacement.
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Affiliation(s)
- He Cai
- Graduate student, Graduate Prosthodontics, Department of Prosthodontics, West China School of Stomatology, Sichuan University, Chengdu, China
| | - Shuying Yang
- Lecturer, Department of General Dentistry and Emergency, State Key Laboratory of Military Stomatology, School of Stomatology, Fourth Military Medical University, Xi'an, China
| | - Xibo Pei
- Lecturer, Department of Prosthodontics, West China School of Stomatology, Sichuan University, Chengdu, China
| | - Hai Qing
- Assistant Professor, Department of Restorative Dentistry, Temple University Kornberg School of Dentistry, Philadelphia, Penn
| | - Jian Wang
- Associate Professor, Department of Prosthodontics, West China School of Stomatology, Sichuan University, Chengdu, China.
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Nowakowska D, Raszewski Z, Ziętek M, Saczko J, Kulbacka J, Więckiewicz W. The Setting Time of Polyether Impression Materials after Contact with Conventional and Experimental Gingival Margin Displacement Agents. J Prosthodont 2016; 27:182-188. [DOI: 10.1111/jopr.12471] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/12/2016] [Indexed: 11/29/2022] Open
Affiliation(s)
- Danuta Nowakowska
- Department of Dental Materials; Wroclaw Medical University; Wroclaw Poland
| | | | - Marek Ziętek
- Department of Periodontology; Wroclaw Medical University; Wroclaw Poland
| | - Jolanta Saczko
- Department of Medical Biochemistry; Wroclaw Medical University; Wroclaw Poland
| | - Julita Kulbacka
- Department of Medical Biochemistry; Wroclaw Medical University; Wroclaw Poland
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Bennani V, Aarts JM, Schumayer D. Correlation of pressure and displacement during gingival displacement: An in vitro study. J Prosthet Dent 2016; 115:296-300. [DOI: 10.1016/j.prosdent.2015.08.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Revised: 08/19/2015] [Accepted: 08/20/2015] [Indexed: 11/30/2022]
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15
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Ahmed SN, Donovan TE, Rau CT. Accurate Elastomeric Impressions: The Importance of Effective Soft Tissue Management. J ESTHET RESTOR DENT 2016; 28:5-7. [PMID: 26729222 DOI: 10.1111/jerd.12191] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Sumitha N Ahmed
- Assistant Professor, Department of Operative Dentistry, UNC School of Dentistry at Chapel Hill, Chapel Hill, NC, USA
| | - Terry E Donovan
- Professor and Section Head for Biomaterials, Department of Operative Dentistry, UNC School of Dentistry at Chapel Hill, Chapel Hill, NC, USA
| | - Clayton T Rau
- Lieutenant Commander, United States Navy, Camp Lejeune, Jacksonville, NC, USA
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Stuffken M, Vahidi F. Preimpression troughing with the diode laser: A preliminary study. J Prosthet Dent 2015; 115:441-6. [PMID: 26723098 DOI: 10.1016/j.prosdent.2015.10.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Revised: 10/13/2015] [Accepted: 10/13/2015] [Indexed: 10/22/2022]
Abstract
STATEMENT OF PROBLEM The mechanical-chemical technique and the use of a laser are methods for displacing the gingiva to make an accurate impression of the preparation for a complete crown. The tissue needs to be displaced and the hemorrhage controlled to capture the prepared finishing line in the impression. The degree of undesirable gingival recession after these displacement techniques is unknown. PURPOSE The purpose of this pilot clinical study was to clinically monitor and compare the regeneration of the gingival tissue by using 2 methods of gingival displacement in the same participant: the mechanical-chemical technique with double cords impregnated with aluminum chloride and the 810 nm diode laser (Odyssey; Ivoclar Vivadent AG). MATERIAL AND METHODS A total of 6 participants needing 2 crowns on natural teeth were included in this study. At the first visit, the teeth were prepared with a 0.5-mm subgingival finishing line and interim crowns were fabricated. One of the teeth was randomly assigned to the double cord technique with 2 (# 000 and # 1) impregnated 5% aluminum chloride cords and the other to the 810 nm diode laser. An adjacent tooth served as a control. A device was made that would function as a fixed reference point for the measurements at different time intervals. A notch was created on the device to position the digital ruler between the occlusal notch and the free gingival margin to measure the distances. The measurements were recorded for each patient before displacement of the gingiva and at the time of cementation of the definitive crowns. The patients were followed at 1 week, 3 weeks, and 8 weeks after cementation of the definitive crowns. RESULTS The amount of recession with the cord impregnated with aluminum chloride was 0.26 mm 8 weeks after cementation of the definitive crowns with a range between 0.00 mm and 0.72 mm. The diode laser showed an average recession of 0.27 mm with a range between 0.01 mm and 0.68 mm. CONCLUSIONS This study found an average loss of gingival height of 0.26 mm for the double cord technique and 0.27 mm for the laser. The amount of recession was considered not clinically significant.
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Affiliation(s)
| | - Farhad Vahidi
- Associate Professor, Department of Prosthodontics, New York University College of Dentistry, New York, NY
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