-
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 -
Journal of Indian Prosthodontic Society 2023The aim was to compare the efficacy of various herbal disinfectants on irreversible hydrocolloid impressions and to investigate the effectiveness of three herbal...
AIM
The aim was to compare the efficacy of various herbal disinfectants on irreversible hydrocolloid impressions and to investigate the effectiveness of three herbal disinfectants and a chemical disinfectant against particular pathogens.
SETTINGS AND DESIGN
In vitro -a comparative study.
MATERIALS AND METHODS
The following methodology was followed to achieve the objectives. Four maxillary impressions were made for each selected patient with irreversible hydrocolloid impression material. The predisinfection swabs were taken from impression sites of teeth 17, 13, 27, and 23 (FDI system of tooth numbering). The impressions were immersed in all four different disinfectants such as 2% glutaraldehyde, Aloe vera solution, 50% neem oil, and apple vinegar solution, then the postdisinfection swabs were taken from the same sites 17,13,27,23 and then cultured onto sheep blood agar and examined for growth, and colony forming units (CFUs) of Streptococcus viridans, Streptococcus mutans, Streptococcus sanguis, and Actinomyces viscosus. The comparative analysis was done for the predisinfection and postdisinfection values in each study group.
STATISTICAL ANALYSIS USED
Descriptive analysis, Kruskal Wallis test, Mann Whitney post hoc test, Wilcoxon signed rank test.
RESULTS
The results revealed that the mean CFUs of S. viridans, S. mutans, S. sanguis, and A. viscosus during postdisinfection samples were statistically significant when compared to predisinfection samples. Multiple comparison of the mean CFUs of all 4 microorganisms in the control group and in 50% Neem oil group was significantly lesser compared to A. vera and Apple Vinegar group.
CONCLUSION
CFUs of S. viridans, S. mutans, S. sanguis, and A. viscosus significantly decreased in the 50% neem oil group as well as the control group. As a result, 50% Neem oil was a viable option for disinfecting alginate impressions.
Topics: Humans; Disinfectants; Acetic Acid; Anti-Infective Agents; Colloids
PubMed: 37929369
DOI: 10.4103/jips.jips_364_22 -
Journal of Indian Prosthodontic Society 2023The intraoral scanners are digital devices used to digitise the oral tissues. The accuracy of the intraoral scanners has been studied under different environmental... (Clinical Trial)
Clinical Trial
Comparative analysis on efficiency and accuracy of parallel confocal microscopy and three-dimensional in motion video with triangulation technology-based intraoral scanner under influence of moisture and mouth opening - A crossover clinical trial.
AIM
The intraoral scanners are digital devices used to digitise the oral tissues. The accuracy of the intraoral scanners has been studied under different environmental conditions, but there might be differences that occur in the actual oral environment, which is still in question. The aim of the study was to evaluate the accuracy and efficiency of Parallel Confocal Microscopy and 3D in motion video with triangulation technology-based intraoral scanners under the influence of moisture and mouth opening.
SETTINGS AND DESIGN
This was an Cross over clinical controlled study.
MATERIALS AND METHODS
The controlled in vivo study included healthy subjects who were in need of CBCT for the purpose of locating the position of unerupted third molars before going abroad for a job. The subjects were exposed to scans in the upper and lower jaws with two intraoral scanners based on 3D motion video technology with triangulation (Medit) and parallel confocal microscopy (Trios) under the influence of two oral conditions, which were moisture (presence and absence of moisture) and mouth opening (30 mm and 50 mm, respectively). A total of 96 scans were obtained and superimposed individually over the reference CBCT scans to find the deviations in the Geomagic Rapidform (version 2020, USA) software. The efficiency of the scanners was calculated by recording the time taken and the number of images obtained after each scan.
STATISTICAL ANALYSIS USED
The significance was calculated by using the independent and paired sample t test in SPSS software (IBM, version 23).
RESULTS
Based on the surface analysis, the trueness of the intra-oral scanners had statistically significant differences when compared between 3D in motion video technology with Triangulation and Parallel Confocal Microscopy (P < 0.05) whereas no statistical significance was observed in precision. There was a significant difference observed in the efficiency of the intra-oral scanners (P < 0.05).
CONCLUSION
There is a significant difference in the accuracy and efficiency of the intraoral scanners under the influence of oral conditions, such as different moisture levels and mouth opening conditions. 3D in motion video technology with Triangulation showed better results with the least deviation than Parallel Confocal Microscopy.
Topics: Humans; Computer-Aided Design; Dental Impression Technique; Imaging, Three-Dimensional; Microscopy, Confocal; Technology; Cross-Over Studies
PubMed: 37929362
DOI: 10.4103/jips.jips_65_23 -
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 -
The Journal of Prosthetic Dentistry Oct 2023Gingival displacement is used in prosthodontics to obtain an accurate impression. However, randomized clinical trials to analyze the performance of different gingival...
STATEMENT OF PROBLEM
Gingival displacement is used in prosthodontics to obtain an accurate impression. However, randomized clinical trials to analyze the performance of different gingival displacement products are lacking.
PURPOSE
The purpose of this prospective, comparative randomized clinical trial was to evaluate the clinical effectiveness of 3 gingival displacement techniques: Racegel cordless, Racegel with a cord, and Racestyptine with a cord.
MATERIAL AND METHODS
A prospective, multicenter randomized, open label, 3-arm parallel group study was carried out in private dental practices. Patients with prepared teeth with healthy gingiva were recruited to make impressions before and after gingival displacement, which were digitized. Lateral and vertical gingival displacements were measured with computer-aided 3-dimensional analysis performed by a single operator who was blinded to the technique and the patient. For mean lateral gingival displacement, each gingival displacement method was compared with a required clinical value of 200 µm with the Student t test. The comparison of means among the 3 groups was performed using an ANOVA. Periodontal indices were recorded immediately and 7 to 14 days after gingival displacement. The percentages were compared with the chi-squared test or the Fisher exact test (α=.05 for all tests).
RESULTS
Eighty-eight participants were enrolled. The mean lateral gingival displacement obtained by Racestyptine with a cord (253 ±59 µm, P<.001) and by Racegel with a cord (247 ±61 µm, P<.001) were significantly higher than 200 µm. Lateral displacement observed with Racegel cordless was 207 ±57 µm (P=.53). For vertical gingival displacement, no difference among the 3 techniques was found. The astringent effect of these products was confirmed by the absence of crevicular fluid or bleeding. No periodontal damage was observed immediately or 7-14 days after displacement.
CONCLUSIONS
The study showed that cord impregnated with Racestyptine and Racegel with or without a cord provided a sufficient sulcus opening before impression making in prosthodontics, consistent with the clinical requirements for lateral displacement.
PubMed: 37919130
DOI: 10.1016/j.prosdent.2023.09.027 -
Journal of Applied Oral Science :... 2023The use of a fiber glass post (FGP) type and choice of FGP diameter to restore endodontically treated incisors without ferrule is controversial. This study evaluated...
OBJECTIVE
The use of a fiber glass post (FGP) type and choice of FGP diameter to restore endodontically treated incisors without ferrule is controversial. This study evaluated survival rate and failure mode of severely compromised central incisors without ferrule rehabilitated using resin-based composite (RBC) with or without FGP with different diameters.
METHODOLOGY
A total of 60 decoronated bovine incisors without a ferrule were endodontically treated and prepared for 1.4, 1.6, and 1.8 mm diameter FGPs (Whitepost System DC 0.5, Fit 0.4, and DCE 0.5; FGM). Half of the teeth received FGPs cemented using dual-cure resin cement (Allcem Core; FGM), the other half were filled using only bulk-fill RBC (OPUS Bulk Fill; FGM). The crowns were directly restored with RBC. The roots were embedded in polystyrene resin and the periodontal ligament was simulated with polyether impression material. Fatigue testing was conducted under 5 Hz cyclic loading at 30 degrees to the incisal edge, beginning at 50 N (5,000 cycles) as a warmup. After, the load was increased 100 N every 15,000 cycles until fracture occurred. All specimens were subjected to transillumination, micro-CT analysis, and digital radiography before and after fatigue testing. Fracture mode was classified according to severity and repair potential. Data were analyzed with Kaplan-Meier survival test and post hoc log-rank test (α=0.05) for pairwise comparisons.
RESULTS
Using FGP significantly increased the number of cycles to failure, irrespective of FGP diameters (p=0.001). The FGP diameters had no statistically significant effect on cycles to failure or failure mode.
CONCLUSION
Using FGP without ferrule improved survival rate of structurally severely compromised central incisors compared with rehabilitation without FGP. The diameter of the FGPs had no effect on the survival rate and failure mode.
Topics: Animals; Cattle; Post and Core Technique; Composite Resins; Tooth, Nonvital; Crowns; Dental Materials; Glass; Dental Stress Analysis; Tooth Fractures; Dental Restoration Failure
PubMed: 37909530
DOI: 10.1590/1678-7757-2023-0241 -
JPMA. the Journal of the Pakistan... Oct 2023To determine the current trends in complete denture education in undergraduate dental colleges.
OBJECTIVE
To determine the current trends in complete denture education in undergraduate dental colleges.
METHODS
The survey-based study was conducted in April and May 2020 at undergraduate dental colleges of Pakistan, and comprised heads of the Prosthodontics Department at all dental colleges across Pakistan having at least one batch of final year dental students. Data was collected using an online predesigned questionnaire that explored theoretical and practical teaching patterns of complete denture prosthodontics in the undergraduate years, and the materials and practices of students when constructing complete dentures in the clinics. The participants were given the option of choosing more than one option where needed. Data was analysed using SPSS 23.
RESULTS
Of the 49 subjects approached, 40(81.6%) returned the forms duly filled; 11(27.5%) from public-sector institutions and 29(72.5%) from the private sector. There were 26(65%) institutions which required that their undergraduate students fabricate 2-4 conventional complete dentures. In all 40(100%) colleges, faculty gave live clinical demonstrations before students fabricated conventional complete dentures in the outpatient departments. Teaching strategy included small group discussions in 25(62.5%) institutions. Green stick 40(100%), zinc oxide eugenol 40(100%) and impression compound 39(97.2%) were the materials of choice for various steps of impression making. In all the 40(100%) institutions, students fabricated conventional complete dentures during their prosthodontics rotation. Immediate, copy and overdentures were constructed by students in 8(20%), 3(7.5%) and 8(20%) institutions, respectively.
CONCLUSION
Majority of the dental schools used similar impression materials and techniques for fabricating conventional complete dentures. Didactic teaching of conventional and unconventional complete dentures was being carried out at a huge majority of the dental institutions studied.
Topics: Humans; Curriculum; Pakistan; Education, Dental; Schools, Dental; Denture, Complete; Students
PubMed: 37876065
DOI: 10.47391/JPMA.9710 -
BMC Oral Health Oct 2023The variabilities in design and material of scan bodies have a major role in the positional transfer accuracy of implants. The purpose of this invitro study was to...
BACKGROUND
The variabilities in design and material of scan bodies have a major role in the positional transfer accuracy of implants. The purpose of this invitro study was to compare the 3D transfer accuracy (trueness and precision) of titanium base (TB) abutment position provided by 2 different scan bodies: one-piece scan body (SB) in comparison to two-piece healing abutment and scan peg (HA-SP).
METHODS
A maxillary model with a dummy implant in the 2nd premolar (Proactive Tapered Implant; Neoss) was 3D printed and TB (Ti Neolink Mono; Neoss) was tightened on the implant and scanned by using a laboratory scanner (inEos X5; Dentsply Sirona) (reference scan). An SB (Elos Medtech) and an HA-SP (Neoss) were subsequently connected to the implant and were scanned 10 times each by using the same scanner (test scans). All the scans were exported as STL files and imported into CAD software where the TBs were formed. Test scans were superimposed on reference scans for transfer accuracy analysis using 3D metrology software (GOM Inspect; GOM GmbH) in terms of angular deviation in vertical and horizontal directions, linear deviation in each XYZ axis of TBs and total linear deviation in all axes. Statistical analysis was done using independent sample t test. When Levene's test for equality of variances was significant, Welch's t-test was used. (P value < 0.05) RESULTS: Significant differences were found amongst the tested groups in both angular and linear deviation in terms of trueness with less deviation values for the SB group (P < 0.001). For the precision, significant differences were found amongst the tested groups in angular deviation in vertical direction with less deviation value for the SB group compared to HA-SP group (P < 0.001). However, no significant difference was found between the tested groups regarding the angular deviation in horizontal direction (P = 1.000). Moreover, significant differences were found amongst the tested groups in linear deviations with less linear deviations in XYZ axes for SB compared to HA-SP group (P = 0.020, < 0.001, = 0.010 respectively).
CONCLUSIONS
SB showed less angular and linear deviation values in the 3D positional transfer of TB than HA-SP indicating higher degree of accuracy of SB.
Topics: Humans; Computer-Aided Design; Titanium; Dental Impression Technique; Models, Dental; Dental Implants; Imaging, Three-Dimensional
PubMed: 37821890
DOI: 10.1186/s12903-023-03399-9