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Dental and Medical Problems 2021Making accurate impressions of dental implants and transferring their three-dimensional (3D) position to master casts is critical for the passive fit of prosthetic...
BACKGROUND
Making accurate impressions of dental implants and transferring their three-dimensional (3D) position to master casts is critical for the passive fit of prosthetic frameworks.
OBJECTIVES
This study aimed to assess the effect of dental implant angulation on the dimensional accuracy of master casts.
MATERIAL AND METHODS
An acrylic model with 2 external hexagonal implants was used in this in vitro experimental study. The impressions of the model were made in 42 positions, with different angulation of the 2 implants, ranging from +15° to -15°, by means of the open-tray and closed-tray impression techniques, using a polyvinyl siloxane impression material. The spatial coordinates of the implants were measured on the X, Y and Z axes. The dimensional accuracy of the impressions made at different positions (parallel, convergent and divergent) and different angulation of the implants were determined. The data was analyzed using the one-way analysis of variance (ANOVA), Student's t test and Tukey's test.
RESULTS
Casts with the lowest accuracy were obtained when the 2 implants were divergent by 25° (R = 1.1336). However, the position of the 2 implants had no significant effect on the dimensional accuracy of the master casts. The error rate was 0.4181 in the open-tray technique and 0.5095 in the closed-tray technique, with no significant difference between them (p > 0.05). The angulation of the 2 implants had a significant effect on the dimensional accuracy of the master casts (p = 0.0001).
CONCLUSIONS
Considering the significant effect of implant angulation in the range from +15° to -15° relative to the longitudinal axis on the dimensional accuracy of master casts, further studies are required to reach a final conclusion in this respect.
Topics: Dental Implants; Dental Impression Materials; Dental Impression Technique; Humans; Models, Dental
PubMed: 34994115
DOI: 10.17219/dmp/133894 -
Journal of Prosthodontic Research Apr 2023To determine the effect of a dynamic impression lining material (DIL) on the retention and stability of mandibular complete dentures (LCD), masticatory performance, and... (Randomized Controlled Trial)
Randomized Controlled Trial
Evaluation of dynamic impression lining material effects on masticatory function and the oral health-related quality of life of complete denture wearers: A six-month randomized controlled trial.
PURPOSE
To determine the effect of a dynamic impression lining material (DIL) on the retention and stability of mandibular complete dentures (LCD), masticatory performance, and the oral health-related quality of life (OHRQoL) of the patients wearing complete denture (CD) compared with those wearing a denture with conventional hard denture liner (HL).
METHODS
Twenty-five patients who wore CD with an ill-fitting LCD were randomly assigned to two groups: LCD relined with DIL (Dynamic impression lining material) or HL (Tokuyama® Rebase II (fast)). Three objective measures (denture retention, stability, and masticatory performance) were measured. The OHRQoL was also measured using the Thai version of oral impacts on daily performance. Outcomes were measured at six time points: baseline, 3 days, 1 week, 1 month, 3 months, and 6 months after relining. Outcome changes were analyzed using a generalized estimating equation, and all models were adjusted for age, mandibular ridge form, and CD age at a 5% significance level.
RESULTS
After LCD relining, the frequency and severity of adverse oral impacts significantly decreased. In the DIL group, denture pain occurred on and off over six months, and an ill-fitting denture impacted at one month. In the HL group, denture pain continuously decreased over time. At 3 months, changes in the clinical properties of DIL were observed, including perceived odor. The material also peel-off from the denture base, and plaque accumulation was observed. In contrast, the HL properties remained stable for over 6 months.
CONCLUSIONS
Although DIL improves denture retention and stability, masticatory performance, and the OHRQoL of the patients who wear CD, oral adverse effects were not eliminated. The clinical properties of DILs changed at 3 months, while the HL remained relatively stable for up to 6 months.(The clinical trial registration number: Thai Clinical Trials Registry (TCTR) number TCTR20210625005.).
Topics: Humans; Quality of Life; Patient Satisfaction; Denture, Complete; Dental Impression Materials; Pain; Mastication
PubMed: 35793983
DOI: 10.2186/jpr.JPR_D_22_00004 -
The Journal of Prosthetic Dentistry Oct 2022Scannable healing abutments are a convenient option to facilitate impression making for implant-supported restorations. However, studies evaluating the accuracy of the...
STATEMENT OF PROBLEM
Scannable healing abutments are a convenient option to facilitate impression making for implant-supported restorations. However, studies evaluating the accuracy of the impression technique with scannable healing abutments are lacking.
PURPOSE
The purpose of this in vitro study was to evaluate the accuracy of implant impression techniques with scannable healing abutments.
MATERIALS AND METHODS
A partially edentulous mandibular dentiform model was fabricated with an epoxy resin, and implants were placed in the mandibular right second premolar and first molar areas. A maxillary dentiform model was then fabricated, and both models were mounted on an articulator. Scan data were obtained from the mounted models and set as the reference scans. The experimental models were divided into 4 groups (n=10). The conventional pick-up impression technique and definitive casts were used in group CI. The scan data from the definitive casts were obtained with a 3D model scanner. An intraoral scanner with a digital body scan was used in group DS. Group MS yielded definitive casts with dual-arch impressions with scannable healing abutments. The fabricated definitive casts were mounted and scanned with a 3D cast scanner. Intraoral scanning with scannable healing abutments was used in group IS. In all 4 groups, the interarch relationship in the maximum intercuspal position was obtained by scanning the facial aspect. The center of the implant head was set as a measurement point for linear intra-arch deviations and implant angle deviations. The mesiopalatal cusp tip of the maxillary right first molar was used to calibrate the linear interarch deviations. The data obtained from each group were compared with the data from the reference scan. As the data were not normally distributed, the Kruskal-Wallis test and Bonferroni correction were used for the analysis (α=.05).
RESULTS
Group MS exhibited significantly higher deviations in linear intra-arch and implant angles compared with the other groups (P<.05). No significant difference was found between the groups in linear interarch deviations (P>.05).
CONCLUSIONS
The accuracy of intraoral scanning with scannable healing abutments was comparable with that of conventional pick-up impression techniques and digital scans with scan bodies. However, model scanning with scannable healing abutments may not be clinically acceptable for implant impressions.
Topics: Humans; Dental Impression Technique; Dental Impression Materials; Models, Dental; Dental Implants; Mouth, Edentulous; Computer-Aided Design
PubMed: 33832762
DOI: 10.1016/j.prosdent.2020.06.042 -
The Journal of Prosthetic Dentistry Mar 2023Ingestion or aspiration of foreign objects may present as a significant complication with various common dental procedures. The most reported ingested or aspirated...
Ingestion or aspiration of foreign objects may present as a significant complication with various common dental procedures. The most reported ingested or aspirated dental materials have included endodontic instruments and metal restorative and prosthetic materials, which can often be identified clinically and radiographically from their relative radiodensities. The authors present an unusual report of lodged impression material in the hypopharynx, which was not detectable radiographically.
Topics: Humans; Hypopharynx; Dental Impression Materials; Foreign Bodies
PubMed: 34284870
DOI: 10.1016/j.prosdent.2021.06.020 -
The Journal of Prosthetic Dentistry Dec 2021New polyvinyl siloxane (PVS) materials with enhanced properties have been developed to improve and facilitate implant impression techniques. However, studies on their...
STATEMENT OF PROBLEM
New polyvinyl siloxane (PVS) materials with enhanced properties have been developed to improve and facilitate implant impression techniques. However, studies on their accuracy are lacking.
PURPOSE
The purpose of this in vitro study was to determine the accuracy and precision of implant impressions made with some recently introduced materials on a simulated patient requiring an all-on-4 implant-supported prosthesis. Well-established polyether materials were also evaluated as a comparison. The variables considered were material type, consistency, splinting or not splinting techniques, and implant angulation.
MATERIAL AND METHODS
A reference master model was made by inserting 4 implants at angles of 0, 5, and 10 degrees. Eighty impressions were made at 37 °C in wet conditions by using a standardized technique. Eight groups (n=10) were created using monophasic, single-viscosity materials (Hydrorise Implant Medium, HIM-ns; Hydrorise Implant Medium, HIM; Honigum Mono, HM; Impregum, IMP), and 2-viscosity materials (Hydrorise Implant Heavy+Light-ns, HIH+L-ns; Hydrorise Implant Heavy+Light, HIH+L; Honigum Heavy+Light, HH+L; and Permadyne and Garant [Heavy+Light, PeH+L]). Hydrorise materials were used with splinting and not splinting (ns) techniques. The reference points located on the connecting platforms of the transfer copings (TCP) were compared with the same points on the implant connecting platforms (ICP) located in the reference model. The accuracy and precision of the impressions were determined as linear 3D errors and standard deviation between each TCP-ICP couple by using an optical coordinate measuring machine (OCMM).
RESULTS
PVS materials were generally better than polyether materials, with Hydrorise materials (HIM and HIH+L) showing significantly better accuracy and precision (30.9 ±14.4 μm and 28.7 ±15.5 μm, respectively) than IMP and PeH+L polyethers (44.2 ±16 μm and 43.8 ±17.6 μm, respectively; P<.001). Honigum materials were statistically similar to Hydrorise materials (P=.765). The values shown by Hydrorise nonsplinted groups (HIH+L-ns and HIM-ns) were not statistically different from those of the splinted polyether impressions (P=.386). The viscosities (monophasic or heavy+light) had no effect on accuracy, but monophasic material positively influenced precision (HIM and HIH+L, P=.001). No correlation was found between implant angulation and accuracy (multilevel analysis and Kendall rank correlation coefficient=-0.065; P=.133).
CONCLUSIONS
Recently introduced materials designed for implant impressions showed significantly higher accuracy and precision; even with the unfavorable nonsplinting technique, the new materials performed similarly to, or better than, polyether materials. Although the transfer coping splinting technique generally improved the accuracy and precision of Hydrorise materials, the effect was significant only within HIH+L groups.
Topics: Dental Implants; Dental Impression Materials; Dental Impression Technique; Humans; Models, Dental
PubMed: 33526247
DOI: 10.1016/j.prosdent.2020.10.017 -
Journal of Biological Regulators and... 2021For dental impression of a prepared tooth, the goal is a void-free negative representation from which an accurate cast of a tooth and its surrounding tissue can be...
For dental impression of a prepared tooth, the goal is a void-free negative representation from which an accurate cast of a tooth and its surrounding tissue can be reproduced. This in-vitro study assessed and compared the reproduction accuracies of surface detail obtained with three different dental elastomeric impression materials: vinyl polysiloxane (VPS), vinyl polyether silicone (VPES), and polyether (PE). A stainless-steel model with two abutments was used, with impressions taken 10 times for each material, for 20 abutment impressions per group, using a two-phase, one-step technique (heavy body/light body). The impressions were removed and assessed for numbers of enclosed voids and open voids visible on the surface. The defect frequency was 95% for impressions with the VPS and VPES materials, and 30% for the PE material. No significant differences were seen for number of impressions with defects for VPS versus VPES. Significant differences were seen for VPS and VPES versus the PE material (P <.05). No significant differences were seen for the defect type distributions across these three impression materials. The PE impression material showed better accuracy for reproduction of surface detail of these dental impressions compared to the VPS and VPES impression materials.
Topics: Dental Impression Materials; Dental Impression Technique; Materials Testing; Models, Dental; Reproducibility of Results; Surface Properties
PubMed: 33435664
DOI: 10.23812/20-561-A -
BMC Research Notes Jun 2022Since there is no material in the market met all the ideal requirements of an impression material, thus in an attempt to find one, hybridization between the two most...
OBJECTIVE
Since there is no material in the market met all the ideal requirements of an impression material, thus in an attempt to find one, hybridization between the two most commonly used impression materials were done. The aim of the hybridization was to obtain a new material combining the good merits of both and eliminate their shortcomings. Thus, this study aimed to assess the impact of hybridization between polyether with addition silicone on tear strength and elastic recovery of the new material and compare such effect with regard to parent materials.
RESULTS
A polyether (PE), polyvinyl siloxanse (PVS) and vinyl polyether silicone (VPES) hybrid elastomers were used in the present study. Tear strength was measured one hour after setting time of each material according to the manufacturer and the three materials showed statistically comparable tear strength in N/mm. Elastic recovery was evaluated one minute after the setting time recommended by the manufacturer. The three materials were statistically insignificant from each other, and all met the ISO4823 requirement of having greater than 96.5% recovery.
Topics: Dental Impression Materials; Elasticity; Materials Testing; Polyvinyls; Resins, Synthetic; Silicone Elastomers; Surface Properties
PubMed: 35761301
DOI: 10.1186/s13104-022-06110-3 -
The Journal of Prosthetic Dentistry Oct 2022The technology behind optical scanners has greatly improved recently, making their dental application advantageous. While their accuracy is now comparable with that of... (Meta-Analysis)
Meta-Analysis Review
Patient preference and clinical working time between digital scanning and conventional impression making for implant-supported prostheses: A systematic review and meta-analysis.
STATEMENT OF PROBLEM
The technology behind optical scanners has greatly improved recently, making their dental application advantageous. While their accuracy is now comparable with that of conventional impression materials, whether these techniques have other advantages is unclear.
PURPOSE
The purpose of this systematic review and meta-analysis was to determine whether digital scanning for implant-supported restorations is more time-efficient and convenient for the patient.
MATERIAL AND METHODS
The study was conducted on September 23, 2020 using 4 different databases (Medline, Cochrane, Web of Science, Scopus) searching for clinical studies that compared the time needed and/or patient perceptions between those who had undergone the digital scanning procedure and those who had undergone conventional impression making.
RESULTS
Twelve studies met the inclusion criteria for qualitative and quantitative analysis. Outcome variables were measured as standard mean differences (SMDs) by following a fixed-effects model or random-effects model (in the case of high heterogeneity). Digital scanning was more time-efficient and was preferred by patients for all 4 analyzed outcomes (comfort, anxiety, nausea, time perception).
CONCLUSIONS
Digital scanning was found to be more time-efficient and convenient than conventional impression making for implant-supported restorations. Additional randomized controlled trials are needed to confirm the findings of this review.
Topics: Humans; Dental Impression Technique; Computer-Aided Design; Patient Preference; Dental Implants; Dental Impression Materials
PubMed: 33678434
DOI: 10.1016/j.prosdent.2020.11.042 -
Minerva Stomatologica Apr 2020Alginic acid is a polysaccharide widely present in the cellular walls of brown algae. Alginate is widely used as a mold material in dentistry, in the production of... (Review)
Review
Alginic acid is a polysaccharide widely present in the cellular walls of brown algae. Alginate is widely used as a mold material in dentistry, in the production of prostheses and in the production of positives for small-scale casting. It is also used in the pharmaceutical, cosmetic and food industries for various uses. The purpose of our study is to assess whether the chemical and physical characteristics of water can influence the characteristics and performance of these materials. These impression materials are often marketed as a powder to be mixed with water, but water is not included during the purchase. We have considered different articles, but unfortunately the results that speak of this topic are few and contain little information. We have therefore carried out a review of the present literature on Pubmed and Embase search engine. The same product used by two people with two different waters will have different characteristics. The possibility of knowing these effects could allow for more performing materials and above all for identical and reproducible materials. In conclusions, the results indicate to follow the manufacturer's instructions, and eventually turn to the use of automatic devices.
Topics: Alginates; Dental Impression Materials; Materials Testing; Powders
PubMed: 32489090
DOI: 10.23736/S0026-4970.19.04293-6 -
BioMed Research International 2019Recent data indicates limited awareness and compliance on infection prevention procedures by dental offices and by dental laboratories. Guidelines for infection... (Review)
Review
Recent data indicates limited awareness and compliance on infection prevention procedures by dental offices and by dental laboratories. Guidelines for infection prevention in dentistry have been published by Centres for Disease Control and Prevention since 2003; the section "IX-Special consideration" includes a subsection concerning the prevention in dental laboratories, but it has not been modernised in later versions to fit the needs of traditional and computer-aided technology. Traditional techniques required disinfecting items (impression, chewing waxes, and appliances) with well-suited products, which are also chosen for limiting impression changes or appliance deterioration. Effective procedures are available with difficulties. Some of these contain irritant or non-eco-friendly disinfectants. The transport of impression, to dental laboratories, is often delayed with limited precautions for limiting cross-infection. Gypsum casts are frequently contaminated mainly by bacteria and their antibiotic-resistant strains and even stored for long periods during dental implant supported restoration and orthodontic therapy, becoming a hidden source of infection. Nowadays, computer-aided design/computer-aided manufacturing technology seems to be an interesting way to promote both business and safety, being more comfortable for patients and more accurate than traditional technology. A further advantage is easier infection prevention since, for the most part, mainly digital impression and casts are not a source of cross-infection and the transport of contaminated items is reduced and limited to try-in stages. Nevertheless, a peculiar feature is that a digital electronic file is of course unalterable, but may be ruined by a computer virus. Additionally, the reconditioning of scanner tips is determinant for the optical characteristics and long term use of the scanner, but information for its reconditioning from producers is often limited. This study focuses on some critical points including (a) insufficient guidelines, (b) choice of proper procedure for scanner reconditioning, and (c) data protection in relation to patient privacy.
Topics: Computer-Aided Design; Dental Implants; Dental Impression Materials; Dental Impression Technique; Dentistry; Humans; Infections
PubMed: 31467901
DOI: 10.1155/2019/6092018