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The Cochrane Database of Systematic... Apr 2018Edentulism is relatively common and is often treated with the provision of complete or partial removable dentures. Clinicians make final impressions of complete dentures... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Edentulism is relatively common and is often treated with the provision of complete or partial removable dentures. Clinicians make final impressions of complete dentures (CD) and removable partial dentures (RPD) using different techniques and materials. Applying the correct impression technique and material, based on an individual's oral condition, improves the quality of the prosthesis, which may improve quality of life.
OBJECTIVES
To assess the effects of different final-impression techniques and materials used to make complete dentures, for retention, stability, comfort, and quality of life in completely edentulous people.To assess the effects of different final-impression techniques and materials used to make removable partial dentures, for stability, comfort, overextension, and quality of life in partially edentulous people.
SEARCH METHODS
Cochrane Oral Health's Information Specialist searched the following databases: Cochrane Oral Health's Trials Register (to 22 November 2017), the Cochrane Central Register of Controlled Trials (CENTRAL) (Cochrane Register of Studies, to 22 November 2017), MEDLINE Ovid (1946 to 22 November 2017), and Embase Ovid (21 December 2015 to 22 November 2017). The US National Institutes of Health Trials Registry (ClinicalTrials.gov) and the World Health Organization International Clinical Trials Registry Platform were searched for ongoing trials. No restrictions were placed on language or publication status when searching the electronic databases, however the search of Embase was restricted by date due to the Cochrane Centralised Search Project to identify all clinical trials and add them to CENTRAL.
SELECTION CRITERIA
We included randomised controlled trials (RCTs) comparing different final-impression techniques and materials for treating people with complete dentures (CD) and removable partial dentures (RPD). For CD, we included trials that compared different materials or different techniques or both. In RPD for tooth-supported conditions, we included trials comparing the same material and different techniques, or different materials and the same technique. In tooth- and tissue-supported RPD, we included trials comparing the same material and different dual-impression techniques, and different materials with different dual-impression techniques.
DATA COLLECTION AND ANALYSIS
Two review authors independently, and in duplicate, screened studies for eligibility, extracted data, and assessed the risk of bias for each included trial. We expressed results as risk ratios (RR) for dichotomous outcomes, and as mean differences (MD) or standardised mean differences (SMD) for continuous outcomes, with 95% confidence intervals (CI), using the random-effects model. We constructed 'Summary of findings' tables for the main comparisons and outcomes (participant-reported oral health-related quality of life, quality of the denture, and denture border adjustments).
MAIN RESULTS
We included nine studies in this review. Eight studies involved 485 participants with CD. We assessed six of the studies to be at high risk of bias, and two to be at low risk of bias. We judged one study on RPD with 72 randomised participants to be at high risk of bias.Overall, the quality of the evidence for each comparison and outcome was either low or very low, therefore, results should be interpreted with caution, as future research is likely to change the findings.Complete denturesTwo studies compared the same material and different techniques (one study contributed data to a secondary outcome only); two studies compared the same technique and different materials; and four studies compared different materials and techniques.One study (10 participants) evaluated two stage-two step, Biofunctional Prosthetic system (BPS) using additional silicone elastomer compared to conventional methods, and found no evidence of a clear difference for oral health-related quality of life, or quality of the dentures (denture satisfaction). The study reported that BPS required fewer adjustments. We assessed the quality of the evidence as very low.One study (27 participants) compared selective pressure final-impression technique using wax versus polysulfide elastomeric (rubber) material. The study did not measure quality of life or dentures, and found no evidence of a clear difference between interventions in the need for adjustments (RR 0.81, 95% CI 0.38 to 1.70). We assessed the quality of the evidence as very low.One study compared two stage-two step final impression with alginate versus silicone elastomer. Oral health-related quality of life measured by the OHIP-EDENT seemed to be better with silicone (MD 7.20, 95% CI 2.71 to 11.69; 144 participants). The study found no clear differences in participant-reported quality of the denture (comfort) after a two-week 'confirmation' period, but reported that silicone was better for stability and chewing efficiency. We assessed the quality of the evidence as low.Three studies compared single-stage impressions with alginate versus two stage-two step with elastomer (silicone, polysulfide, or polyether) impressions. There was no evidence of a clear difference in the OHIP-EDENT at one month (MD 0.05, 95% CI -2.37 to 2.47; two studies, 98 participants). There was no evidence of a clear difference in participant-rated general satisfaction with dentures at six months (MD 0.00, 95% CI -8.23 to 8.23; one study, 105 participants). We assessed the quality of the evidence as very low.One study compared single-stage alginate versus two stage-two step using zinc-oxide eugenol, and found no evidence of a clear difference in OHIP-EDENT (MD 0.50, 95% CI -2.67 to 3.67; 39 participants), or general satisfaction (RR 3.15, 95% CI 0.14 to 72.88; 39 participants) at six months. We assessed the quality of the evidence as very low.Removable partial denturesOne study randomised 72 participants and compared altered-cast technique versus one-piece cast technique. The study did not measure quality of life, but reported that most participants were satisfied with the dentures and there was no evidence of any clear difference between groups for general satisfaction at one-year follow-up (low-quality evidence). There was no evidence of a clear difference in number of intaglio adjustments at one year (RR 1.43, 95% CI 0.61 to 3.34) (very low-quality evidence).
AUTHORS' CONCLUSIONS
We conclude that there is no clear evidence that one technique or material has a substantial advantage over another for making complete dentures and removable partial dentures. Available evidence for the relative benefits of different denture fabrication techniques and final-impression materials is limited and is of low or very low quality. More high-quality RCTs are required.
Topics: Dental Impression Materials; Dental Impression Technique; Denture Design; Denture Retention; Denture, Partial, Removable; Dentures; Humans; Mouth, Edentulous; Quality of Life; Randomized Controlled Trials as Topic
PubMed: 29617037
DOI: 10.1002/14651858.CD012256.pub2 -
Dental and Medical Problems 2018New glass-ceramic restorative materials have been developed over the last few years, with enhanced strength characteristics along with desirable optical properties that... (Review)
Review
New glass-ceramic restorative materials have been developed over the last few years, with enhanced strength characteristics along with desirable optical properties that make them ideal for the fabrication of esthetic crowns and veneers. The purpose of this paper was to provide an overview of the current state of the art of porcelain veneers as a viable option for the esthetic treatment of anterior teeth, and to illustrate the potential of the newly-developed glass-ceramics. Some historical background about the development of the porcelain veneer concept is provided. A list of indications and contraindications for porcelain veneers is followed by their preparation designs, with emphasis on the importance of maintaining the preparation boundaries within the enamel. Impression-taking procedures, provisional restoration fabrication, the choice of porcelain materials and their intaglio surface treatment are all discussed. A case where veneers made with a lithium-disilicate glass-ceramic were used to improve the appearance of maxillary anterior teeth is included. Several studies reporting on the longevity of porcelain veneers up to 12 years are discussed.
Topics: Acid Etching, Dental; Ceramics; Dental Impression Technique; Dental Porcelain; Dental Restoration Failure; Dental Veneers; Humans
PubMed: 30152626
DOI: 10.17219/dmp/90729 -
Journal of Dental Research Dec 2014Advances in digital impression technology and manufacturing processes have led to a dramatic paradigm shift in dentistry and to the widespread use of computer-aided... (Review)
Review
Advances in digital impression technology and manufacturing processes have led to a dramatic paradigm shift in dentistry and to the widespread use of computer-aided design/computer-aided manufacturing (CAD/CAM) in the fabrication of indirect dental restorations. Research and development in materials suitable for CAD/CAM applications are currently the most active field in dental materials. Two classes of materials are used in the production of CAD/CAM restorations: glass-ceramics/ceramics and resin composites. While glass-ceramics/ceramics have overall superior mechanical and esthetic properties, resin-composite materials may offer significant advantages related to their machinability and intra-oral reparability. This review summarizes recent developments in resin-composite materials for CAD/CAM applications, focusing on both commercial and experimental materials.
Topics: Chemical Phenomena; Composite Resins; Computer-Aided Design; Dental Materials; Dental Prosthesis Design; Surface Properties
PubMed: 25344335
DOI: 10.1177/0022034514553976 -
International Journal of Environmental... Jan 2021Digital impressions in implant dentistry rely on many variables, and their accuracy, particularly in complete edentulous patients, is not well understood. The purpose... (Review)
Review
INTRODUCTION
Digital impressions in implant dentistry rely on many variables, and their accuracy, particularly in complete edentulous patients, is not well understood. The purpose of this literature review was to determine which factors may influence the accuracy of digital impressions in implant dentistry. Emphasized attention was given to the design of the intra-oral scan body (ISB) and scanning techniques.
MATERIALS AND METHODS
A Medline, PubMed and EBSCO Host databases search, complemented by a hand search, was performed in order to select relevant reports regarding the appliance of digital impressions in implant dentistry. The search subject included but was not limited to accuracy of digital impressions in implant dentistry, digital scanning techniques, the design and material of the ISBs, and the depth and angulation of the implant. The related titles and abstracts were screened, and the remaining articles that fulfilled the inclusion criteria were selected for full-text readings.
RESULTS
The literature search conducted for this review initially resulted in 108 articles, among which only 21 articles fulfilled the criteria for inclusion. Studies were evaluated according to five subjects: accuracy of digital impressions in implant dentistry; the design and material of the intra-oral scan bodies; scanning technique; the influence of implants depth/angulations on the digital impression and accuracy of different intra-oral scanner devices.
CONCLUSIONS
The accuracy of digital impressions in implant dentistry depends on several aspects. The depth/angulation of the implant, the experience of the operator, the intra-oral scanner used, and environmental conditions may influence the accuracy of digital impressions in implant dentistry. However, it seems that ISBs' design and material, as well as scanning technique, have a major impact on the trueness and precision of digital impressions in implant dentistry. Future research is suggested for the better understanding of this subject, focusing on the optimization of the ISB design and scanning protocols.
Topics: Computer-Aided Design; Dental Impression Technique; Dentistry; Humans; Mouth, Edentulous; Prostheses and Implants
PubMed: 33498902
DOI: 10.3390/ijerph18031020 -
Marine Drugs Dec 2018Hydrocolloids were the first elastic materials to be used in the dental field. Elastic impression materials include reversible (agar-agar), irreversible (alginate)... (Review)
Review
Hydrocolloids were the first elastic materials to be used in the dental field. Elastic impression materials include reversible (agar-agar), irreversible (alginate) hydrocolloids and synthetic elastomers (polysulfides, polyethers, silicones). They reproduce an imprint faithfully, providing details of a high definition despite the presence of undercuts. With the removal of the impression, being particularly rich in water, the imprints can deform but later adapt to the original shape due to the elastic properties they possess. The advantages of using alginate include the low cost, a better tolerability on the part of the patient, the ease of manipulation, the short time needed for execution, the instrumentation and the very simple execution technique and possibility of detecting a detailed impression (even in the presence of undercuts) in a single step. A comprehensive review of the current literature was conducted according to the PRISMA guidelines by accessing the NCBI PubMed database. Authors conducted a search of articles in written in English published from 2008 to 2018. All the relevant studies were included in the search with respect to the characteristics and evolution of new marine derived materials. Much progress has been made in the search for new marine derived materials. Conventional impression materials are different, and especially with the advent of digital technology, they have been suffering from a decline in research attention over the last few years. However, this type of impression material, alginates (derived from marine algae), have the advantage of being among the most used in the dental medical field.
Topics: Agar; Alginates; Animals; Colloids; Dental Impression Materials; Dental Impression Technique; Humans; Materials Testing; Surface Properties; Tooth
PubMed: 30597945
DOI: 10.3390/md17010018 -
Dental Materials Journal Jan 2020An optical-impression by an intraoral scanner (IOS) involves optically measuring the surface shape of the target teeth or gums directly in the patient's mouth. IOSs have...
An optical-impression by an intraoral scanner (IOS) involves optically measuring the surface shape of the target teeth or gums directly in the patient's mouth. IOSs have many advantages, such as reduce patients pain and discomfort, the operator's burden and the risk on infection, real-time impression scanning and visualization, simple replication and selective scanning, reduction of cost and waste of materials and detection of dental caries and crack . IOSs have become one of the most valuable dental-treatment devices for patients, dentists, dental technicians, and dental hygienists. The IOS accuracy matches or supersedes the accuracy of the conventional-impression and indirect method with working models. IOS is clinically applicable in restoration up to four units. IOS's high reproducibility, information-processing ability, multimedia capability, and simplicity and speed in communication can apply to group examination and identification of disaster victims or dementia patients.
Topics: Computer-Aided Design; Dental Caries; Dental Impression Technique; Dentistry; Humans; Imaging, Three-Dimensional; Models, Dental; Reproducibility of Results
PubMed: 31723066
DOI: 10.4012/dmj.2019-224 -
The International Journal of... 2018To evaluate the accuracy and precision of a digital scanner used to scan four implants positioned according to an immediate loading implant protocol and to assess the...
PURPOSE
To evaluate the accuracy and precision of a digital scanner used to scan four implants positioned according to an immediate loading implant protocol and to assess the accuracy of an aluminum framework fabricated from a digital impression.
MATERIALS AND METHODS
Five master casts reproducing different edentulous maxillae with four tilted implants were used. Four scan bodies were screwed onto the low-profile abutments, and a digital intraoral scanner was used to perform five digital impressions of each master cast. To assess trueness, a metal framework of the best digital impression was produced with computer-aided design/computer-assisted manufacture (CAD/CAM) technology and passive fit was assessed with the Sheffield test. Gaps between the frameworks and the implant analogs were measured with a stereomicroscope. To assess precision, three-dimensional (3D) point cloud processing software was used to measure the deviations between the five digital impressions of each cast by producing a color map. The deviation values were grouped in three classes, and differences were assessed between class 2 (representing lower discrepancies) and the assembled classes 1 and 3 (representing the higher negative and positive discrepancies, respectively).
RESULTS
The frameworks showed a mean gap of < 30 μm (range: 2 to 47 μm). A statistically significant difference was found between the two groups by the 3D point cloud software, with higher frequencies of points in class 2 than in grouped classes 1 and 3 (P < .001).
CONCLUSION
Within the limits of this in vitro study, it appears that a digital impression may represent a reliable method for fabricating full-arch implant frameworks with good passive fit when tilted implants are present.
Topics: Computer-Aided Design; Dental Implants; Dental Impression Materials; Dental Impression Technique; Dental Prosthesis, Implant-Supported; Humans; Jaw, Edentulous; Models, Dental
PubMed: 29518813
DOI: 10.11607/ijp.5535 -
Journal of Prosthodontic Research Oct 2014Ceramics are widely used as indirect restorative materials in dentistry because of their high biocompatibility and pleasing aesthetics. The objective is to review the... (Review)
Review
PURPOSE
Ceramics are widely used as indirect restorative materials in dentistry because of their high biocompatibility and pleasing aesthetics. The objective is to review the state of the arts of CAD/CAM all-ceramic biomaterials.
STUDY SELECTION
CAD/CAM all-ceramic biomaterials are highlighted and a subsequent literature search was conducted for the relevant subjects using PubMed followed by manual search.
RESULTS
Developments in CAD/CAM technology have catalyzed researches in all-ceramic biomaterials and their applications. Feldspathic glass ceramic and glass infiltrated ceramic can be fabricated by traditional laboratory methods or CAD/CAM. The advent of polycrystalline ceramics is a direct result of CAD/CAM technology without which the fabrication would not have been possible.
CONCLUSIONS
The clinical uses of these ceramics have met with variable clinical success. Multiple options are now available to the clinicians for the fabrication of aesthetic all ceramic restorations.
Topics: Aluminum Oxide; Aluminum Silicates; Biocompatible Materials; Ceramics; Cerium; Computer-Aided Design; Crystallization; Dental Impression Technique; Dental Materials; Dental Porcelain; Dental Prosthesis Design; Dental Restoration, Permanent; Esthetics, Dental; Glass; Humans; Magnesium; Zirconium
PubMed: 25172234
DOI: 10.1016/j.jpor.2014.07.003 -
Clinical Oral Investigations Dec 2021The primary aim of this systematic review was to evaluate whether intraoral scanning (IOS) is able to reduce working time and improve patient-reported outcome measures... (Review)
Review
OBJECTIVES
The primary aim of this systematic review was to evaluate whether intraoral scanning (IOS) is able to reduce working time and improve patient-reported outcome measures (PROMs) compared to conventional impression (CI) techniques, taking into account the size of the scanned area. The secondary aim was to verify the effectiveness of IOS procedures based on available prosthodontic outcomes.
MATERIALS AND METHODS
Electronic and manual literature searches were performed to collect evidence concerning the outcomes of IOS and CI performed during the treatment of partially and complete edentulous patients for tooth- or implant-supported restorations. Qualitative analysis was conducted to evaluate the time efficiency and PROMs produced by the two different techniques. Clinical prosthodontic outcomes were analyzed among the included studies when available.
RESULTS
Seventeen studies (9 randomized controlled trials and 8 prospective clinical studies) were selected for qualitative synthesis. The 17 included studies provided data from 430 IOS and 370 CI performed in 437 patients. A total of 7 different IOS systems and their various updated versions were used for digital impressions. The results demonstrated that IOS was overall faster than CI independent of whether quadrant or complete-arch scanning was utilized, regardless of the nature of the restoration (tooth or implant supported). IOS was generally preferred over CI regardless of the size of the scanned area and nature of the restoration (tooth- or implant-supported). Similar prosthodontic outcomes were reported for workflows implementing CI and IOS.
CONCLUSIONS
Within the limitations of this systematic review, IOS is faster than CI, independent of whether a quadrant or complete arch scan is conducted. IOS can improve the patient experience measured by overall preference and comfort and is able to provide reliable prosthodontic outcomes.
CLINICAL RELEVANCE
Reduced procedure working time associated with the use of IOS can improve clinical efficiency and the patient experience during impression procedures. Patient-reported outcome measures (PROMs) are an essential component of evidence-based dental practice as they allow the evaluation of therapeutic modalities from the perspective of the patient. IOS is generally preferred by patients over conventional impressions.
Topics: Computer-Aided Design; Dental Implants; Dental Impression Technique; Humans; Patient Comfort; Prospective Studies; Prosthodontics
PubMed: 34568955
DOI: 10.1007/s00784-021-04157-3