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Cureus Nov 2023Effective and clear communication between the dentist and dental technician plays a vital role in rendering quality prostheses for patients. When fabricating a removable...
BACKGROUND
Effective and clear communication between the dentist and dental technician plays a vital role in rendering quality prostheses for patients. When fabricating a removable dental prosthesis, it is uncertain if the information received by the dental laboratory technician is clear and sufficient. This investigation aimed to assess dental technicians' perceptions of the quality of dentists' communication on the fabrication of removable partial dentures (RPDs) in Saudi Arabia.
METHODOLOGY
After obtaining the institutional review board (IRB) approval from Riyadh Elm University, Riyadh, Saudi Arabia, a cross-sectional survey on a convenient sample of 115 dental technicians registered with the Saudi Commission for Health Specialties was conducted in January 2022. The voluntary participation of 94 technicians fabricating RPDs was included. A 19-item online questionnaire was developed, including quality of written instruction, selection of impression trays, and impression materials for RPD fabrication, shared through Google Docs. Descriptive statistics were tabulated, and responses were displayed as a percentage of the total.
RESULTS
Of the 94 study subjects, 35% had less than five years of experience, 44% stated that they routinely receive work authorizations with clear instructions, 13% always used digital technology to fabricate prostheses, and 58% reported difficulty with communicated work authorization by dentists having less than five years of experience. Thirty-three respondents (35.1%) reported that 75% or more of the fabricated partial dentures were cast framework partials. Thirty-three respondents (35.1%) indicated that the master casts received for partial framework construction were usually accurate. Tooth alterations, however, were reported as usually adequate by only 28 respondents (29.8%). For creating the artificial gingiva portion of cast partials, 56 respondents (59.6%) preferred heat-cured acrylic resin. Furthermore, 40 respondents (42.6%) said that 75% or more of the requested partials were entirely made out of acrylic resin. Regarding case design discussions, 26 respondents (27.7%) always engaged with dentists, while 39 (41.5%) did so occasionally.
CONCLUSION
The obtained assessments pointed to the fact that dental technicians expressed a perception of inadequacy regarding the work authorizations provided by dentists for the fabrication of RPDs, where they seemingly felt that the instructions conveyed by the dentists were not sufficiently comprehensive or clear.
PubMed: 38054138
DOI: 10.7759/cureus.48245 -
International Journal of Implant... Dec 2023A high transfer accuracy of the intraoral implant position to a model is required, to manufacture implant-supported restorations. However, clinically relevant deviations...
PURPOSE
A high transfer accuracy of the intraoral implant position to a model is required, to manufacture implant-supported restorations. However, clinically relevant deviations persist between the intraoral implant position and the model obtained, even for the benchmark conventional custom implant impressions with polyether. Thus, new approaches using 3-D printed impression trays may increase the transfer accuracy of implant impressions. The ability to adjust parameters such as the thickness of the layers and the influence of the openings in the impression tray could potentially affect accuracy.
METHODS
Four different types of impression trays (n = 10 for each group) for the conventional impression technique were investigated: conventional custom impression tray, customized foil tray, chairside 3-D printed impression tray with the SHERA system, and the Primeprint system using an implant master model with four implants in the posterior region and a reference cube. After plaster model casting, all models were measured using a coordinate measuring machine, and the deviation from the reference dataset was determined. A statistical ANOVA analysis was performed (p < 0.05).
RESULTS
Chairside 3-D printed impression trays showed the best results, followed by conventional custom impression trays. Implant impressions obtained using a customized foil tray exhibited the lowest accuracy. Statistically significant differences were observed between 3-D printed impression trays and conventional custom impression and customized foil trays (p < 0.05). Whereas, the implant position did not have any significant influence on accuracy (p > 0.05).
CONCLUSIONS
Chairside 3-D printed impression trays significantly increase the transfer accuracy for implant impression taking.
Topics: Dental Impression Materials; Dental Implants; Dental Impression Technique; Models, Dental; Research Design
PubMed: 38052992
DOI: 10.1186/s40729-023-00516-9 -
BMC Oral Health Dec 2023The goal behind this study is to answer the question "In tooth-supported fixed partial dentures (FPDs), does the digital impression techniques compared to fabrications... (Meta-Analysis)
Meta-Analysis
PURPOSE OF THE STUDY
The goal behind this study is to answer the question "In tooth-supported fixed partial dentures (FPDs), does the digital impression techniques compared to fabrications using conventional impression methods improve the marginal and internal fit?
BACKGROUND
The incorporation of digital technology in the fabrication of fixed partial dentures (FPDs) has accelerated over the past decade. This study is directed at evaluating the marginal and internal fit of FPDs manufactured using digital approaches compared to conventional techniques. The need for updated data has encouraged this review.
MATERIALS AND METHODS
An electronic search was conducted in PubMed, Scopus, Web of Science, and the Grey Database to identify relevant studies. The Modified Methodological Index for Non-Randomized Studies (MINORS) was used to assess the risk of bias in in vitro experiments. The key results of this meta-analysis were the standard mean differences (SMDs) and 95% confidence intervals (CI) of each main variance, marginal fit, and internal fit between the digital and conventional techniques. Additional analyses were performed to assess the significance of three subgroup parameters: method of digitalization, cement spacer thickness, and span length, and their influence on the fit of the FPDs.
RESULTS
Based on predefined criteria, of the seven articles included in this systematic review, only five were selected for the quantitative data analysis. The marginal fit results were (P = 0.06; SMD: -1.88; 95% CI: - 3.88, 0.11) (P > 0.05) and the internal fit results were (P = 0.02; SMD: -0.80; 95% CI: - 1.49, - 0.10) (P < 0.05). Regarding the subgroup analyses, the method of digitalization subgroup results were (P = 0.35; SMD: -1.89; 95% CI: - 3.89, 0.11) and (P = 0.80; SMD: -0.80; 95% CI: - 1.49, - 0.11) for marginal and internal fit, respectively. The span length results were (P = 0.10; SMD: -1.89; 95% CI: - 3.89, 0.11) for marginal fit and (P = 0.02; SMD: -0.80; 95% CI: - 1.49, - 0.11) for internal fit. The cement spacer thickness (P = 0.01; SMD: -1.89; 95% CI: - 3.89, 0.11) and (P = 0.04; SMD: -0.80; 95% CI: - 1.49, - 0.11) for marginal and internal fit, respectively.
CONCLUSION
Tooth-retained fixed partial dentures FPDs produced by digital scanning and computer-aided design/computer-aided manufacturing (CAD/CAM) systems can significantly enhance the internal fit compared with those manufactured by traditional methods. Intraoral scanners can replace conventional impressions for the fabrication of FPDs because they minimize the operating time and reduce patient pain. Further clinical studies are required to obtain more conclusive results.
SYSTEMATIC REVIEW REGISTRATION
This systematic review and meta-analysis was registered in the International Prospective Register of Systematic Reviews (PROSPERO), registration number CRD42021261397.
Topics: Humans; Dental Marginal Adaptation; Denture, Partial, Fixed; Computer-Aided Design; Research Design; Dental Prosthesis Design
PubMed: 38049754
DOI: 10.1186/s12903-023-03628-1 -
International Journal of Dentistry 2023Dental clinicians and professionals need an affordable, nontoxic, and effective disinfectant against infectious microorganisms when dealing with the contaminated dental...
Dental clinicians and professionals need an affordable, nontoxic, and effective disinfectant against infectious microorganisms when dealing with the contaminated dental impressions. This study evaluated the efficiency of hypochlorous acid (HOCl) as an antimicrobial disinfectant by spraying technique for the alginate impression materials, compared with sodium hypochlorite, and its effect on dimensional stability and reproduction of details. HOCl with a concentration of 200 ppm for 5 and 10 min was compared with the control group (no treatment) as a negative control and with sodium hypochlorite (% 0.5) as a positive control. , , and were selected to assess the antimicrobial activity with the colony forming unit test in addition to the dimensional stability and reproduction of details tests. The results revealed that HOCl had significant antimicrobial activity against all tested microorganisms and experimental time. Interestingly, HOCl showed no impact on the dimensional stability of alginate impression material. HOCl could be an effective antimicrobial agent for alginate impression material without interfering with their surface details and dimensional stability.
PubMed: 38021346
DOI: 10.1155/2023/8584875 -
Dentistry Journal Oct 2023The aim of this study was to determine the mechanical implications of four-unit fixed dental prostheses (FDPs) made of (1) monolithic zirconium dioxide (ZR O), (2)...
UNLABELLED
The aim of this study was to determine the mechanical implications of four-unit fixed dental prostheses (FDPs) made of (1) monolithic zirconium dioxide (ZR O), (2) polymethylmethacrylate (PMMA), (3) metal ceramic (PFM) and (4) impression resin (3DPP).
METHODS
Four groups were studied with eight samples for each material (n: 32). Each structure was weighed, subjected to compressive tests and analyzed using 3D FEA.
RESULTS
PMMA presented the lowest structural weight (1.33 g), followed by 3DPP (1.98 g), ZR O (6.34 g) and PFM (6.44 g). In fracture tests, PMMA presented a compressive strength of 2104.73 N and a tension of 351.752 MPa; followed by PFM, with a strength of 1361.48 N and a tension of 227.521 MPa; ZR O, with a strength of 1107.63 N and a tension of 185.098 MPa; and 3DPP, with a strength of 1000.88 N and a tension of 143.916 MPa. According to 3D FEA, 3DPP presented the lowest degree of deformation (0.001 mm), followed by PFM (0.011 mm), ZR O (0.168 mm) and PMMA (1.035 mm).
CONCLUSIONS
The weights of the materials did not have a direct influence on the mean values obtained for strength, stress or strain. Since the performance was related to the tension and forces supported by the structures in critical zones, the importance of considering design factors is clear. In vitro and 3D FEA assays allowed us to simulate different scenarios for the mechanical properties of certain materials before evaluating them clinically. Thus, they can generate predictions that would allow for the design of a better research methodology in future clinical trials.
PubMed: 37999013
DOI: 10.3390/dj11110249 -
The Journal of Prosthetic Dentistry Feb 2024Knowledge of the fabrication trueness and margin quality of additively manufactured (AM) laminate veneers (LVs) when different intraoral scanners (IOSs) and finish line...
Influence of intraoral scanner and finish line location on the fabrication trueness and margin quality of additively manufactured laminate veneers fabricated with a completely digital workflow.
STATEMENT OF PROBLEM
Knowledge of the fabrication trueness and margin quality of additively manufactured (AM) laminate veneers (LVs) when different intraoral scanners (IOSs) and finish line locations are used is limited.
PURPOSE
The purpose of this in vitro study was to evaluate the fabrication trueness and margin quality of AM LVs with different finish line locations digitized by using different IOSs.
MATERIAL AND METHODS
An LV preparation with a subgingival (sub), equigingival (equi), or supragingival (supra) finish line was performed on 3 identical maxillary right central incisor typodont teeth. Each preparation was digitized by using 2 IOSs, (CEREC Primescan [PS] and TRIOS 3 [TS]), and a reference LV for each finish line-IOS pair (n=6) was designed. A total of 90 LVs were fabricated by using these files and urethane acrylate-based definitive resin (Tera Harz TC-80DP) (n=15). Each LV was then digitized by using PS to evaluate fabrication trueness (overall, external, intaglio, and marginal surfaces). Each LV was also qualitatively evaluated under a stereomicroscope (×60), and the cervical and incisal margin quality was graded. Fabrication trueness and cervical margin quality were evaluated by using 2-way analysis of variance, while Kruskal-Wallis and Mann Whitney-U tests were used to evaluate incisal margin quality (α=.05).
RESULTS
The interaction between the IOS type and the finish line location affected measured deviations at each surface (P≤.020). PS-sub and TS-supra had higher overall trueness than their counterparts. and the subgingival finish line resulted in the lowest trueness (P≤.005). PS and the subgingival finish line led to the lowest trueness of the external surface (P≤.001). TS-sub had the lowest intaglio surface trueness among the TS subgroups, and PS-sub had higher trueness than TS-sub (P<.001). PS-sub and PS-supra had higher marginal surface trueness than their TS counterparts (P<.001). TS resulted in higher cervical margin quality (P=.001).
CONCLUSIONS
Regardless of the IOS tested, subgingival finish lines resulted in the lowest trueness. The effect of IOS on the measured deviations varied according to the surface evaluated and finish line location. The cervical margin quality of AM LVs was higher when TS was used.
Topics: Imaging, Three-Dimensional; Workflow; Computer-Aided Design; Dental Impression Technique; Models, Dental
PubMed: 37978007
DOI: 10.1016/j.prosdent.2023.10.026 -
Clinical Implant Dentistry and Related... Feb 2024Full-arch IOS scan of edentulous areas rehabilitated with dental implants is nowadays still described as an unpredictable procedure. To improve the accuracy, a universal...
BACKGROUND
Full-arch IOS scan of edentulous areas rehabilitated with dental implants is nowadays still described as an unpredictable procedure. To improve the accuracy, a universal scan template (UST®) is proposed in this article. The clinician can easily assemble the template with a mechanical coupling, by matching the scan bodies with objects of known dimension characterized by specific markers. The UST® facilitates the scanning of an entire arch on scan bodies, reducing the learning curve, simplifying acquisition movements, shortening the scanning time, and drastically reducing the risk of distortions and aberrations of the scans.
MATERIALS AND METHODS
In a case series study on 12 patients, the improvement in the accuracy of the scans with UST® was validated by comparing the STL files derived from scans with and without the guide in place. A titanium bar was produced from each optical impression.
RESULTS
The bars obtained from the optical impressions taken without UST® were found to be nonpassive in the mouth in the majority of the cases. On the contrary with the use of UST® we obtained 12 passive prosthetic rehabilitations.
CONCLUSIONS
The proposed solution may represent a valid method to improve the predictability of full arch optical impressions on implants.
Topics: Humans; Preliminary Data; Dental Impression Technique; Models, Dental; Computer-Aided Design; Mouth, Edentulous; Dental Implants; Imaging, Three-Dimensional
PubMed: 37965745
DOI: 10.1111/cid.13292 -
BMC Oral Health Nov 2023This study aimed to determine the relative positioning accuracy of multiple implants utilizing four distinct types of splinting materials.
BACKGROUND
This study aimed to determine the relative positioning accuracy of multiple implants utilizing four distinct types of splinting materials.
METHODS
The purpose of this in-vitro study was to compare the precision of four splinting materials in an open tray impression technique in multiple implant situations. Based on the material used for splinting, four groups were made (n = 40)- Group A: Conventional Method, Group B: Prefabricated Pattern Resin Framework, Group C: Prefabricated Metal Framework, Group D: Light Cured Pattern Resin, these groups were compared with the master model. A heat-cured clear acrylic resin and a master model were constructed. A pilot milling machine drill was used to drill four parallel holes in the anterior and premolar regions, which were later labeled as A, B, C, and D positions from right to left. Then, sequential drilling was carried out, and four 3.75‑mm diameter and 13-mm long ADIN implant analogs with internal hex were placed in the acrylic model using a surveyor for proper orientation. The impression posts were then manually screwed to the implant analogs using an open tray, and they were secured to the implants using 10 mm flat head guide pins with a 15 N.cm torque. 10 Open tray polyether impressions were made, and casts were poured. Each splinting method's distortion values were measured using a coordinate measuring machine capable of recordings in the X-, Y-, and Z-axes. Comparison of mean distances for X1, X2, and X3 was made using the Kruskal-Wallis test, and Pairwise comparison was done using Post Hoc Tukey's Test.
RESULTS
The differences between the groups were significant when assessing the distances X1, X2, and X3 (p < 0.05). The comparison of deviations between the groups revealed a statistically significant difference (p < 0.05) for the deviation distance X3 but not for the deviation distances X1 and X2. For distance Y1, the difference between the groups was statistically significant (p0.05), but it was not significant for distances Y2 and Y3. A statistically significant difference was seen in the comparison between the groups (p < 0.05) for the deviation distances Y1, Y2, and Y3. The results were statistically significant for the distance Z1 comparisons, namely, control vs. Group A (p = 0.012), control vs. Group B (p = 0.049), control vs. Group C (p = 0.048), and control vs. Group D (p = 0.021), and for distance Z3 comparison for control vs. Group A (p = 0.033). The results were statistically insignificant for the distance Z2 comparisons (p > 0.05).
CONCLUSIONS
All splinting materials produced master casts with measurements in close proximity to the reference model. However, prefabricated pattern resin bars splinting showed the highest accuracy among the studied techniques. The most recent splinting techniques using prefabricated metal framework and light-cure pattern resin showed similar accuracy.
Topics: Humans; Dental Implants; Dental Impression Technique; Dental Impression Materials; Models, Dental; Acrylic Resins
PubMed: 37940890
DOI: 10.1186/s12903-023-03583-x -
The Journal of Prosthetic Dentistry Jan 2024Information regarding the effect of tooth color under different light conditions on the accuracy of intraoral complete arch scanning is limited.
STATEMENT OF PROBLEM
Information regarding the effect of tooth color under different light conditions on the accuracy of intraoral complete arch scanning is limited.
PURPOSE
The purpose of this in vitro study was to evaluate the effect of color and ambient light conditions on the accuracy of mandibular complete arch scanning with an intraoral scanner (IOS) using a zirconia restoration model with different shades.
MATERIAL AND METHODS
Five mandible dentition models with zirconia restorations of different shades were fabricated by computer-aided design and computer-aided manufacturing (CAD-CAM). The spectral reflectance and transmittance curves were collected with a spectrophotometer to determine color parameters (Rb, T, S+A, L*, a*, b*, C*, and h). Under 4 different lighting conditions: no light (ZL), natural light (NL), room light (RL), and chair light (CL), each model was scanned 10 times by using an IOS (TRIOS 3). Three-dimensional (3D) deviation analysis and a linear deviation analysis were performed for an accurate quantitative measurement of intraoral scanning. The multivariate test was used to determine significant differences in 3D deviation and linear deviation among groups. The multiple linear regression test was conducted to investigate the relevant independent factors of mean absolute 3D deviation.
RESULTS
The 3D deviation analysis showed that the mean absolute 3D deviation of 3M2 model scanning was the lowest (P<.001). Moreover, under CL and RL, the accuracy results from the 3M2 model scan were demonstrated as significantly better than the tested scans under other light conditions (P=.021). The result of the linear deviation analysis indicated that the variation in distance was only significant between the bilateral canines (P=.032). Ambient light conditions, C*, and h were factors influencing mean absolute 3D deviation (R2=0.593, P<.001).
CONCLUSIONS
Color change influenced the accuracy of intraoral mandibular complete arch scanning under different light conditions. This effect may be attributable to the interaction between the ambient light condition and color parameters such as C* and h.
Topics: Computer-Aided Design; Zirconium; Lighting; Imaging, Three-Dimensional; Dental Impression Technique; Dental Arch
PubMed: 37923645
DOI: 10.1016/j.prosdent.2023.10.001 -
Medical Science Monitor : International... Nov 2023BACKGROUND The aim of this study was to assess and compare the vertical/horizontal dimensions and occlusal accuracy of non-working/opposing casts obtained from three...
BACKGROUND The aim of this study was to assess and compare the vertical/horizontal dimensions and occlusal accuracy of non-working/opposing casts obtained from three different impression materials and 3D print cast. MATERIAL AND METHODS Dentulous Master models simulating a case of a fixed dental prosthesis were mounted on an articulator (control group). Opposing mandibular casts obtained from three different impression materialsand 3-dimensional print constituted test groups , ,and , respectively. Three points, anterior vertical (AV), posterior vertical (PV), and anteroposterior (AP) were compared for dimensional accuracy among casts. Occlusal accuracy was analyzed on Medit Link software at 3 teeth (#13, #17, and #27). After calculating means for each group, the differences were calculated at probability value of P≤0.05 using the single-sample t test, ANOVA, and Tukey test. RESULTS The dimensions were significantly different from those of the mounted master models except in Gp AL(E) and Gp AL(F) at AV dimension and Gp AL(E) at AP dimension (P>0.05). A statistically significant difference of the error of means among the 4 tested groupswere detected only at 2 dimensions (AV and PV) between the Gp AL(E) and Gp 3D-C and between Gp AL(F) and Gp 3D-C groups. Other groups showed no significant differences. CONCLUSIONS The opposing casts obtained from the extended-pour alginate and alginate alternative impression materials showed higher occlusal accuracy compared to conventional alginate and 3D printed casts.
Topics: Humans; Alginates; Mandible; Models, Dental; Printing, Three-Dimensional; Software
PubMed: 37924203
DOI: 10.12659/MSM.941654