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The Journal of Prosthetic Dentistry May 2024The stability of mandibular removable partial dentures with bilateral distal extensions may be improved with the controlled tissue support achieved by using the altered...
Digital comparative analysis in three dimensions of two impression techniques for the bilateral distal extension of partially edentulous mandibular arches: A pilot clinical study.
STATEMENT OF PROBLEM
The stability of mandibular removable partial dentures with bilateral distal extensions may be improved with the controlled tissue support achieved by using the altered cast impression technique, although this process is time-consuming and technique-sensitive.
PURPOSE
The purpose of this pilot clinical study was to compare casts generated from a conventional definitive impression with casts generated from an altered cast impression using a 3-dimensional (3D) analysis software program.
MATERIAL AND METHODS
Three partially edentulous participants with mandibular Kennedy Class I were enrolled, and impressions were made with the 2 techniques and poured in stone. The casts were scanned, aligned, and superimposed by using a 3D analysis software program. Surface deviations were measured to evaluate the differences in displacement induced by the impression on the tissue surface. Five observations were made in 4 different areas on each partially edentulous side. Means from these observations were generated, and the Wilcoxon and Mann Whitney tests were performed for all data to assess the differences between the right and left sides in the same participant and among the 3 participants (α=.05).
RESULTS
The casts made from the altered cast impression had an overall mean ±standard deviation displacement of -0.05 ±1.25 mm on the right and left sides of the mandibular buccal shelf area. Moreover, the greatest overall difference of about 0.45 ±0.41 mm occurred on the lingual slope of the residual ridge, and the differences in the other areas were 0.10 ±0.99 mm (crest of the residual ridge) and 0.16 ±0.66 mm (buccal slope of the residual ridge). The overall differences varied statistically between significance and nonsignificance for the same participant and among the 3 participants.
CONCLUSIONS
A digital comparative analysis of the conventional and altered cast methods of recording the bilateral distal extension areas in partially edentulous participants showed that the altered cast method exhibited more displacement on the buccal vestibule or buccal shelf area compared with other examined areas. The differences between the 2 impression methods in the displacement values among the examined areas were minimal and in close proximity, and such differences may lack clinical significance.
PubMed: 38729790
DOI: 10.1016/j.prosdent.2024.04.022 -
Journal of Dentistry Jul 2024This in vitro study compared the accuracy of conventional versus digital impression techniques for angulated and straight implants using two different impression coping... (Comparative Study)
Comparative Study
OBJECTIVES
This in vitro study compared the accuracy of conventional versus digital impression techniques for angulated and straight implants using two different impression coping and scan body designs.
METHODS
Two implant systems were used: Straumann and Dentegris. Two implants were placed for each system, straight and angulated at 15 degrees mesiodistally. Conventional impressions were made using the splinted open-tray technique using narrow impression coping (NIC) and wide impression coping (WIC). The stone casts produced from the conventional impression were digitized with a lab scanner (3Shape D2000). Digital impressions were made using four intraoral scanners (IOS): 3Shape Trios 3, Medit i700, Cerec Omnicam, and Emerald Planmeca using short scanbodies (SSB) and long scanbodies (LSB). The scanning was repeated ten times to generate the Standard Tessellation Language (STL) files. The distance and angle deviations between impression copings and scanbodies were measured in reference to the master model.
RESULTS
The trueness and precision of SSB and WIC were significantly better than LSB and NIC (p<0.001). The range trueness of the platform deviation was better with SSB (37.1 to 51.9) than LSB (89.6 to 127.9 μm) and for WIC than NIC in conventional impressions (58.2 and 75.1 μm, respectively). The trueness of the angle deviation of digital scans with SSB (0.11 to 0.25 degrees) was significantly better than scans with LSB (0.31 to 0.57 degrees) and for WIC than NIC (0.21 and 0.52 degrees, respectively). The precision of the platform deviation of digital scans with SSB (12.4 to 34.5 μm) was higher than other scans and conventional impressions (42.9 to 71.4 μm). The precision of the angle deviation of Medit i700 and Trios 3 with SSB (0.17 and 0.20 degrees, respectively) was higher than other scans with SSB and conventional impressions (0.54 to 1.63 degrees).
CONCLUSIONS
Digital scans with SSB were more accurate than conventional splinted open-tray impressions. The type of impression coping and scanbody significantly affected the impression accuracy.
CLINICAL SIGNIFICANCE
The use of a short scanbody can increase the accuracy of digital impressions, and wide impression coping can increase the accuracy of conventional impressions, resulting in improved clinical outcomes.
Topics: Dental Impression Technique; Humans; Computer-Aided Design; Dental Implants; Dental Prosthesis Design; Image Processing, Computer-Assisted; Dental Impression Materials; Models, Dental
PubMed: 38714241
DOI: 10.1016/j.jdent.2024.105045 -
Journal of Dentistry Jul 2024To evaluate the positional accuracy of implant analogs in biobased model resin by comparing them to that of implant analogs in model resin casts and conventional analogs... (Comparative Study)
Comparative Study
OBJECTIVES
To evaluate the positional accuracy of implant analogs in biobased model resin by comparing them to that of implant analogs in model resin casts and conventional analogs in dental stone casts.
METHODS
Polyvinylsiloxane impressions of a partially edentulous mandibular model with a single implant were made and poured in type IV dental stone. The same model was also digitized with an intraoral scanner and additively manufactured implant casts were fabricated in biobased model resin (FotoDent biobased model) and model resin (FotoDent model 2 beige-opaque) (n = 8). All casts and the model were digitized with a laboratory scanner, and the scan files were imported into a 3-dimensional analysis software (Geomagic Control X). The linear deviations of 2 standardized points on the scan body used during digitization were automatically calculated on x-, y-, and z-axes. Average deviations were used to define precision, and 1-way analysis of variance and Tukey HSD tests were used for statistical analyses (α = 0.05).
RESULTS
Biobased model resin led to higher deviations than dental stone (all axes, P ≤ 0.031) and model resin (y-axis, P = 0.015). Biobased model resin resulted in the lowest precision of implant analog position (P ≤ 0.049). The difference in the positional accuracy of implant analogs of model resin and stone casts was nonsignificant (P ≥ 0.196).
CONCLUSIONS
Implant analogs in biobased model resin casts mostly had lower positional accuracy, whereas those in model resin and stone casts had similar positional accuracy. Regardless of the material, analogs deviated more towards mesial, while buccal deviations in additively manufactured casts and lingual deviations in stone casts were more prominent.
Topics: Models, Dental; Humans; Polyvinyls; Dental Impression Technique; Computer-Aided Design; Siloxanes; Dental Impression Materials; Dental Prosthesis Design; Imaging, Three-Dimensional; Calcium Sulfate; Resins, Synthetic; Dental Implants; Mandible; Dental Casting Technique; Materials Testing
PubMed: 38703808
DOI: 10.1016/j.jdent.2024.105037 -
Journal of the Korean Association of... Apr 2024The surgical guide is a static computer-assisted device used for implant surgery planning and guidance. By taking an impression and referring to the patients'...
OBJECTIVES
The surgical guide is a static computer-assisted device used for implant surgery planning and guidance. By taking an impression and referring to the patients' three-dimensional computed tomography scan of the desired implant site, a surgical guide can be created. During surgery, the surgical guide aids in achieving the designed implant placement position and direction. We examined and evaluated the long-term clinical outcomes of implant surgery using surgical guides.
MATERIALS AND METHODS
This study investigated a total of 15 patients with 32 implants that were placed using surgical guides from 2009 to 2011 with a mean follow-up period extended beyond 10 years. Patient demographics and implant survival rates were recorded. We analyzed marginal bone loss (MBL) by assessing the radiographs acquired at installation, three months after installation, and one month, one, two, and five years after prosthesis delivery.
RESULTS
The mean patient age was 57.33 years at implant placement. Of the 32 implants, five implants were placed in the anterior region and 27 implants were in the posterior region. Six implants failed and three of them were replaced, resulting in an 81.25% survival rate. The mean follow-up period was 10 years and nine months. Mean MBL compared to post-installation was significantly higher than at three months after installation, and one month, one, two, and five years after prosthesis delivery. Mean MBL at three months after installation, and one month, one year, and two years were significantly higher compared to the previous visit (<0.05). However, MBL at five years after prosthesis delivery did not differ significantly compared to at two years.
CONCLUSION
In this study, implant rehabilitation assisted by surgical guides exhibited favorable survival rates. With the limitation of the sample amount in this study, further research and more samples are required to evaluate the long-term clinical effectiveness of surgical guides.
PubMed: 38693129
DOI: 10.5125/jkaoms.2024.50.2.70 -
The European Journal of Prosthodontics... May 2024The purpose of this in vitro study was to evaluate the dimensional accuracy, trueness, and precision of vinyl siloxane ether (VSXE) and polyvinylsiloxane (PVS)...
INTRODUCTION
The purpose of this in vitro study was to evaluate the dimensional accuracy, trueness, and precision of vinyl siloxane ether (VSXE) and polyvinylsiloxane (PVS) impression materials using different impression techniques.
MATERIAL AND METHODS
A three-dimensional (3D) printed mandibular model with implants and metal rods served as the reference model. Impressions were taken in custom trays, resulting in four groups: PVS-closed-tray, VSXE-closed-tray, PVS-open-tray, and VSXE-open-tray. The reference model and impressions were scanned and analyzed using 3D analysis software to assess the trueness and precision within each group.
RESULTS
There was significant difference in trueness between the groups, with PVS closed tray showing a higher deviation than VSXE-closed-tray and PVS-open-tray. VSXE-open-tray had the lowest deviation, which was statistically significant. In terms of precision, PVS-closed-tray showed the highest deviation, while no significant differences were found among the other groups.
CONCLUSIONS
VSXE impression material with an open tray technique consistently demonstrated the highest levels of accuracy and precision. Conversely, PVS impression material with a closed tray technique yielded less favorable results.
CLINICAL RELEVANCE
Better understanding of trueness and precision of new impression materials with new impression techniques will increase their clinical effectiveness.
Topics: Dental Impression Materials; Siloxanes; Polyvinyls; Dental Impression Technique; Mandible; Humans; Denture, Overlay; Dental Prosthesis, Implant-Supported; Printing, Three-Dimensional; In Vitro Techniques; Models, Dental
PubMed: 38691584
DOI: 10.1922/EJPRD_2638Ghanem11 -
International Journal of Implant... May 2024The purpose of this systematic review was to explore and identify the factors that influence the accuracy of intraoral scanning in implant dentistry, with a specific... (Review)
Review
PURPOSE
The purpose of this systematic review was to explore and identify the factors that influence the accuracy of intraoral scanning in implant dentistry, with a specific focus on scan bodies (ISBs).
METHODS
Following the PRISMA 2020 guidelines, this study conducted a thorough electronic search across MedLine, PubMed, and Scopus to identify relevant studies. Articles were screened based on titles, abstracts, and full texts for relevance. The Robins I tool assessed the risk of bias in various study types. Data extraction occurred based on predetermined parameters for studying specimens and assessing outcomes.
RESULTS
16 studies met the specified criteria and were consequently included in the systematic review. Due to variations in variables and methods across the selected studies, statistical comparison of results was not feasible. Therefore, a descriptive review approach was chosen, acknowledging the substantial heterogeneity in the reviewed literature.
CONCLUSIONS
The precision of virtual scan results is contingent upon diverse characteristics of ISBs and implants. These factors encompass their placement within the dental arch, structural design, shape, material composition, color, and the manufacturing system, all of which contribute to scan accuracy. Additionally, considerations such as the intraoral scanner (IOS) type, scanning technique, use of scan aids, inter-implant distance, scan span, and the number of implants warrant evaluation. In the context of capturing implant positions, intraoral scanning with ISBs demonstrates comparable accuracy to traditional impression methods, particularly in single and short-span scenarios. However, the existing data lacks sufficient information on in vivo applications to formulate clinical recommendations.
Topics: Humans; Dental Implants; Imaging, Three-Dimensional; Computer-Aided Design; Dental Implantation, Endosseous; Dental Prosthesis Design
PubMed: 38691258
DOI: 10.1186/s40729-024-00543-0 -
The Journal of Contemporary Dental... Mar 2024The objective of this study was to assess marginal bone level around single implants inserted in fresh extraction sockets in the anterior maxillary region and instantly...
Immediate Loading Using the Digitalized Customized Restoration of Single-tooth Implants Placed in Fresh Extraction Sockets in the Aesthetic Anterior Maxilla: A 10-Year Prospective Study of Marginal Bone Level.
AIM
The objective of this study was to assess marginal bone level around single implants inserted in fresh extraction sockets in the anterior maxillary region and instantly restored with computer-aided design/computer-aided manufacturing customized temporary crowns cemented on the final abutment.
MATERIALS AND METHODS
A total of 20 patients (15 females and 5 males, with a mean age of 30 years), where 20 were placed in fresh extraction sockets. After raising a full-thickness flap, atraumatic extraction was performed the implant site was prepared and fixtures were stabilized on the palatal bone wall. The implant location was immediately transmitted to the prepared master model using the pick-up impression coping seated in the surgical guide template. Prefabricated abutments were used as the final abutment on the master model, scanned and the crown was planned using computer-aided manufacturing customized software. Later on 8th weeks, abutments were torqued as per the manufacturer's recommendation, and the final crowns were cemented. Using personalized intraoral radiographs marginal bone level was evaluated mesially and distally to the implant shoulder as a reference at implant placement, 8 weeks, 1, 3, 5, and 10 years after loading.
RESULTS
Wholly implants were osteo-integrated positively after 10 years of practical loading, but only 18 were available for clinical and radiological follow-up, and 2 patients with two implants were excluded from the study due to relocation abroad without any implant failure. The average marginal bone loss (MBL) in the current report was 0.16 ± 0.167 mm at crown cementation, 0.275 ± 0.171 mm after 1 year, 0.265 ± 0.171 mm after 3 years, 0.213 ± 0.185 mm after 5 years, and 0.217 ± 0.194 mm at 10 years.
CONCLUSION
The strategy of inserting and not removing the final abutment at the time of implant placement facilitates the establishment of adequate attachment of both soft and hard tissues to the abutment surface, ensuring uninterrupted organization of tissue architecture and offers advantages in helping maintain soft tissue maturation and preventing marginal bone level.
CLINICAL SIGNIFICANCE
Immediately loaded implants in freshly extracted sockets lead to a significant reduction in marginal ridge resorption. The use of a temporary crown on a prefabricated abutment, exclusive of successive abutment manipulation, proved effective in preserving the primarily founding blood clot and served as a prototype for shaping the soft tissue around the previously wounded gum. How to cite this article: Berberi A, El Zoghbi A, Aad G, . Immediate Loading Using the Digitalized Customized Restoration of Single-tooth Implants Placed in Fresh Extraction Sockets in the Aesthetic Anterior Maxilla: A 10-Year Prospective Study of Marginal Bone Level. J Contemp Dent Pract 2024;25(3):213-220.
Topics: Humans; Male; Dental Implants, Single-Tooth; Female; Prospective Studies; Maxilla; Adult; Immediate Dental Implant Loading; Tooth Socket; Computer-Aided Design; Crowns; Alveolar Bone Loss; Dental Abutments; Esthetics, Dental; Tooth Extraction; Dental Prosthesis, Implant-Supported; Dental Prosthesis Design; Dental Implant-Abutment Design; Young Adult
PubMed: 38690692
DOI: 10.5005/jp-journals-10024-3659 -
The Saudi Dental Journal Apr 2024Impressions that maintain their dimensional stability after autoclaving effectively control cross-infection and contamination resulting from a patient's oral secretions.
Comparative analysis of dimensional changes in autoclavable polyvinyl siloxane (PVS) impressions under various Sterilization/Disinfection Protocols: A randomized controlled trial.
BACKGROUND
Impressions that maintain their dimensional stability after autoclaving effectively control cross-infection and contamination resulting from a patient's oral secretions.
PURPOSE
The study aimed to assess the dimensional stability of autoclavable polyvinyl siloxanes after disinfection and sterilization.
METHODS
A stainless steel metal model containing three full veneer crown preparations was fabricated according to ANSI/ADA specification No. 19. Reference grooves were established on the occlusal and axial surfaces of the abutments for accurate measurements. Forty impressions were created from the master model using single-step impression technique monophase polyvinyl siloxane material (AFFINIS, Coltene/Whaledent, Altstatten, Switzerland). The impressions were categorized into four groups: Group A (control, ten untreated impressions), Group B (ten disinfected impressions with 5.25 % sodium hypochlorite [NaOCl]), Group C (ten disinfected impressions with 2 % glutaraldehyde), and Group D (ten autoclaved impressions at 134 °C for 18 min). Subsequently, stone casts were produced using type IV gypsum products (Gelstone , BK Giulini Chemie, Ludwigshafen/Rh., Germany). The dimensional accuracy of the obtained casts was assessed by measuring the inter-abutment measurements (between the abutments) and the intra-abutment measurements (diameter and height of the abutments). These measurements were performed using a universal measuring microscope (Olympus stereomicroscope B061 Imaging Corp. Tokyo, Japan) with a precision of 0.001 mm. The dimensions of the stone casts from the study groups were then compared to those of the control group. Data analysis was performed using a one-way ANOVA with a significance level of α = 0.05.
RESULTS
AFFINIS impressions subjected to chemical disinfection in 5.25 % NaOCl and 2 % glutaraldehyde with different immersion times showed slight expansion in the intra- and inter-abutment measurements. The impressions autoclaved at 134 °C for 18 min showed slight shrinkage in the intra- and inter-abutment measurements. The dimensional change was statistically non-significant, and the percent of dimensional changes within the experimental groups was within the clinically accepted limit (α < 0.5).
CONCLUSION
AFFINIS polyvinyl siloxanes retain dimensional stability suitable for clinical use when subjected to chemical disinfection and steam autoclaving.
PubMed: 38690388
DOI: 10.1016/j.sdentj.2024.01.016 -
Journal of Indian Prosthodontic Society Apr 2024(1) To compare the temperature rise in the pulp chamber with different resin materials used for making provisional fixed partial dentures in anterior and posterior... (Comparative Study)
Comparative Study
AIM
(1) To compare the temperature rise in the pulp chamber with different resin materials used for making provisional fixed partial dentures in anterior and posterior region while using Polyvinylsiloxane impression materials as matrix. (2) To identify a superior provisionalization material based on the amount of heat dissipated suitable for anterior and posterior provisional fixed partial denture fabrication.
SETTINGS AND DESIGN
Temporary crowns and bridges are integral to Fixed Prosthodontics. It has been observed that conventional fixed prosthesis temporisation materials release heat due to the exothermic polymerisation reaction. When such a provisional material is directly let to set on a vital tooth, the heat transfer causes irreversible changes in the pulp tissue depending of the degree of change. Hence, this study observes amount of heat generation in various materials during temporisation procedure, by simulating similar conditions.
MATERIALS AND METHODS
Two Models were fabricated, one simulating missing lateral incisor (Model A) and another simulating missing first molar (Model B). Intact maxillary central incisors and canine for Model A and intact mandibular Second Premolar and Second Molar were selected to act as abutments. These abutment teeth were fitted with the tip of a K-type Thermocouple inside their pulp chambers and these were connected to a digital thermometer. Five temporisation materials were chosen for fabrication of temporary crowns through Direct technique. (1) polymethy methacrylate (Self Cure acrylic), (2) bisacryl composite (Protemp 4), (3) visible light cure urethane dimethacrylate (Revotec LC), (4) barium glass and fumed silica infused methacrylate (Dentsply Integrity) and (5)nano-hybrid composite (VOCO Structur 3). Ten observations were made for each provisional material on each model. During each observation, temperature rise was recorded at 30s interval from the time of application, through the peak and till a decrease in temperature is observed. Polyvinyl siloxane was used as matrix for all except light cure resin, where polypropylene sheet was used.
STATISTICAL ANALYSIS USED
Anova test used for statistical.
RESULTS
ANOVA test revealed that there was a significant difference in the temperature changes associated with the provisional restorative materials used. Among the five, polymethy methacrylate (self cure resin) showed the maximum rise in temperature, followed by bisacryl composite (Protemp 4), visible light cure urethane dimethacrylate (Revotec LC), barium glass and fumed silica infused methacrylate (Dentsply Integrity) and nano-hybrid composite (VOCO Structur 3). There was no comparable difference between Model A and B but an overall reduction of temperature rise was observed in model B.
CONCLUSION
VOCO Structur 3 showed the least temperature rise in the pulp chamber, and overall temperature rise was less for model B which can be attributed to the residual dentin thickness.
Topics: Polymerization; Humans; Dental Pulp Cavity; Siloxanes; In Vitro Techniques; Materials Testing; Composite Resins; Dental Restoration, Temporary; Denture, Partial, Fixed; Temperature; Dental Impression Materials; Dental Materials
PubMed: 38650344
DOI: 10.4103/jips.jips_492_23 -
Journal of Dentistry Jun 2024To assess the impact of including the palate and the number of images recorded during intraoral digital scanning procedure on the accuracy of complete arch scans.
OBJECTIVES
To assess the impact of including the palate and the number of images recorded during intraoral digital scanning procedure on the accuracy of complete arch scans.
METHODS
An experienced operator conducted 40 digital scans of a 3D printed maxillary model and divided them into two groups: 20 with inclusion of the palate (PAL) and 20 without (NPAL). Each set of scans was performed using an intraoral scanner (IOS) (Trios 5; 3Shape A/S; Copenhagen, Denmark). The resulting STL files were imported into the Geomagic Control X software (3D Systems, Rock Hill, SC, USA) for accuracy comparison. A reference STL file was created using a 3Shape E3 laboratory scanner (3Shape Scanlt Dental 2.2.1.0; Copenhagen, Denmark). The number of images captured was recorded during the scanning procedure.
RESULTS
In the case of the right side no statistically significant difference in trueness was detected (84 µm ± 45.6 for PAL and 80.4 ± 40.4 µm for NPAL). In the case of the left side no significant difference in trueness was observed (215.1 ± 70.2 µm for PAL and 233.9 ± 70.7 µm for NPAL). In the case of the arch distortion a statistically significant difference in trueness was seen between the two types of scans (135.3 ± 71.9 µm for PAL and 380.4 ± 255.1 µm for NPAL). The average number of images was 831.25, and 593.8 for PAL and NPAL, respectively.
CONCLUSIONS
Scanning of the palatal area can significantly improve the accuracy of dental scans in cases of complete arches. In terms of the number of images, based on the current results, obvious conclusions could not be drawn, and further investigation is required.
CLINICAL SIGNIFICANCE
Scanning the palate may be beneficial for improving the accuracy of intraoral scans in dentate patients. Consequently, this should be linked to an appropriate scanning strategy that predicts palatal scanning.
Topics: Humans; Dental Impression Technique; Models, Dental; Palate; Dental Arch; Maxilla; Image Processing, Computer-Assisted; Computer-Aided Design; Imaging, Three-Dimensional; Software; Printing, Three-Dimensional; In Vitro Techniques; Dental Impression Materials
PubMed: 38648874
DOI: 10.1016/j.jdent.2024.105014