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Purpose: To compare the 3D accuracy of three scanning strategies and conventional impressions using an edentulous model with six implants. Materials and Methods: An edentulous maxillary master model was fabricated with six equigingival internal connection implants at 0 degrees of angulation. Ten conventional open-tray splinted implant-level impressions were made and poured in stone. A master model and conventional casts were digitized with a reference scanner. Digital impressions were made by calibrated clinicians with a TRIOS 3 intraoral scanner ([IOS] 3Shape) according to three scanning strategies: DIG1 (occlusal-palatal-lingual), DIG2 (S-type motion from buccal to palatal), and DIG3 (scanning two half arches and connecting them at the midline). Each technique was repeated 10 times on the master model. Deviations from the STL datasets (N = 40) were compared to those of the reference master model using the Hexagon Metrology software system PC-DMIS CAD++. Linear distortions (dX, dY, dZ), global linear distortion (dR), and angular distortions (Absdθx, Absdθy) were calculated. Kruskal-Wallis test and mixed linear and logistic regression models were used to compare the original and binary distortion measures between the techniques. Results: The mean dR ranged from 91 μm (conventional method) to 183 μm (DIG1). The mean angular distortion ranged from 0.20 degrees (Absdθx for DIG2) to 0.69 degrees (Absdθy for DIG3). No scan pattern resulted in a more accurate reproduction in any of the measured parameters than the conventional impression method. There were significant differences between the methods for all distortion measures. Conclusions: No group reproduced the 3D position of the six-implant master model below the thresholds for both global linear and angular distortions. All the digital strategies tested were less accurate than the conventional open-tray splinted implant-level impression technique. [ABSTRACT FROM AUTHOR]

Aim: The aim of this study was to compare the accuracy of full‐arch conventional implant impressions using two different materials (A‐silicone and polyether) to full‐arch digital implant impressions produced from two intraoral scanning devices. Materials and Methods: A master model was fabricated representing an edentulous mandible with four implants with internal connection placed at the sites of canines and first molars. The anterior implants were parallel to the residual ridge, while the two posterior implants had an angulation of 15° to the distal and 15° to the lingual respectively. The conventional technique was performed with open‐tray of non‐splinted impression copings. Two different impression materials were used, A‐silicone and polyether at monophase medium body consistencies. The digital impressions were obtained with the use of two different intraoral scanners, after the connection of scan bodies. A total of 10 impressions were produced for each of the four experimental groups. The conventional models as well as the master model were digitized using a high‐resolution laboratory scanner. The STL files of the models and of the intraoral impressions were imported in a powerful superimposition software, for the conduction of measurements in pairs of files. The software calculated the 3D deviations, as well as the linear and angular displacements among scan bodies at the digital files. For "trueness" measurements every STL file of each experimental group was superimposed to the digital master model, while for "precision" measurements all STL files of each experimental group were superimposed to each other. Results and Conclusions: The accuracy of full arch mandibular implant impressions was influenced both by the impression technique used (conventional vs. digital) and the impression material used (A‐silicone vs. polyether) or the intraoral scanner used (Trios vs. Heron).In terms of "trueness," A‐silicone showed the highest impression accuracy with the lowest deviation values, followed by polyether and Trios, but the differences between the three groups were in the majority not statistically significant. Heron showed statistically lower accuracy results in all measurements compared to the other groups.In terms of "precision", conventional impressions with the use of A‐Silicone or polyether were statistically significantly superior to digital impressions with either scanner. A‐Silicone and polyether showed no statistically significant difference between them. [ABSTRACT FROM AUTHOR]

This study compares the fracture strength of teeth restored with conventional round fiber post (CP) and bundle post (BP) in two different lengths. A total of 48 mandibular premolars were selected. Endodontic treatment was performed, and the premolars were divided into four groups (n = 12 per group): Group C9 = 9-mm CP; Group C5 = 5-mm CP; Group B9 = 9-mm BP; Group B5 = 5-mm BP. Post spaces were prepared, and posts were disinfected with alcohol. Silane was applied, and posts were placed with self-etch dual-cure adhesive. The core structures were created using dual-cure adhesive and standardized core-matrix. Specimens were embedded in acrylic, and the periodontal ligament was simulated with polyvinyl-siloxane impression material. Thermocycling was performed, and specimens were then loaded at a 45-degree angle to the long axis. The failure mode was analyzed with x5 magnification, and statistical analyses were performed. No statistical difference was found between post systems and post lengths (P > .05). Chi-square test revealed no statistical difference in the failure mode (P > .05). BP did not affect fracture resistance compared to CP. For the restoration of extremely irregular canals with a fiber post, BP can be used as an alternative system because it does not reduce the fracture strength. If necessary, longer posts can be used without decreasing the fracture resistance. [ABSTRACT FROM AUTHOR]

To compare the morphologic trueness of provisional and definitive restorations constructed with conventional custom impression techniques to those constructed with intra- and extraoral scanning (IEOS), which can digitally transfer the subgingival morphology of the provisional restoration to the definitive restoration. Materials and Methods: Provisional restorations were fabricated on typodonts in which implants were placed. In the conventional method, a customized impression coping was produced by using polymethyl methacrylate resin to transfer the subgingival contour of the provisional restoration. Impressions were taken with silicone impression material, and definitive restorations were made by CAM. The IEOS technique was performed as previously reported. In brief, three individually scanned stereolithography (STL) files were superimposed in CAD software to transfer the morphology of the provisional restoration to the definitive restoration. Definitive restorations were then made by CAM. The provisional and definitive restorations were both scanned by IOS. Scanned data files were superimposed with morphometry software, and the distortions were measured. Student t test was used for statistical analysis. Results: The subgingival morphologies of definitive restorations prepared by the conventional method showed significant negative distortions compared to definitive restorations prepared by the IEOS technique. Conclusion: The IEOS technique can more accurately transfer the subgingival contour of provisional restorations to definitive restorations compared to the conventional customized impression coping technique. [ABSTRACT FROM AUTHOR]

Background: The effectiveness of newly developed elastomeric polymer hybrid siloxane (PVES), which combines the properties of polyethylene (PE) and polyvinyl siloxane (PVS) elastomers, has been a subject of interest in recent studies. This study aimed to assess the physical properties of hybrid PVES materials by analyzing existing data from recent studies on this topic. Methods: A systematic literature search was conducted to retrieve peer-reviewed articles published up to February 5, 2023. The population, intervention, comparison, and pertinent outcomes were specified under the PICO framework. The primary data analysis was performed in Microsoft Excel, while statistical analysis used Meta-Essentials. Results: Of the 1152 articles assessed, 14 met the inclusion criteria. The meta-analysis of the selected studies indicated that polyether (PE) and polyvinyl siloxane (PVS) were highly correlated (two-tailed p-values of 0.000 and 0.001, respectively) with the improved tensile strength of vinyl polyether siloxane (PVES) with a significantly positive effect size. Similarly, the hydrophilic characteristics of PVES were significantly improved compared to those of PE and PVS. PE was a significant contributor to the hydrophilic characteristics of PVES, with a two-tailed p-value of 0.000. The effect size was highly positive for hydrophilicity but showed high heterogeneity. It was also observed that the dimensional accuracy of PVES was comparable to those of PE and PVS, with no statistically significant differences among the three materials. Conclusions: PVES showed promising features, with improved tensile strength and hydrophilic characteristics compared to those of PE and PVS. [ABSTRACT FROM AUTHOR]

This manuscript introduces a novel two-step technique for fabricating mobile dentures post-extraction to streamline prosthodontic rehabilitation. The study utilizes various materials, including dental polymers, metals, ceramics, and composite materials, each chosen for their unique properties that contribute to the final prosthesis’s functionality, durability, and esthetics. The detailed procedure involves an initial occlusal registration immediately following tooth extraction, capturing precise occlusal relationships and a comprehensive dental impression. This approach reduces clinical visits and leverages optimal alveolar ridge morphology. The expected results highlight the efficiency of the technique, reducing treatment time without compromising quality and potentially improving patient satisfaction and prosthodontic outcomes. This innovative method conclusively promises rapid, efficient, and patient-centered dental rehabilitation, emphasizing the need for future research to validate its effectiveness and explore long-term outcomes.

Introduction: The antimicrobial activity and physical properties of Vinyl Siloxane Ether (VSE) impression material, such as dimensional stability, flow, and setting time, play a crucial role in the success of fixed prosthodontics. During impression making, the impression material is exposed to infected blood and saliva, which are potential sources of cross-contamination. Cross-contamination can be decreased or minimised when antimicrobial agents are added to the impression material. The efficacy of nanoparticles like silver, titanium, zinc oxide, and chitosan as antimicrobial agents is continuously researched in dentistry. These particles have the benefit of being small and possessing effective antibacterial characteristics due to their vast surface area, which creates an effective interaction with microbes. Aim: To evaluate and compare the antimicrobial activity and physical properties of VSE impression material incorporated with various concentrations (0.0, 1.0, and 2.5 wt.%) of zinc oxide and chitosan nanoparticles. Materials and Methods: This is an in-vitro study conducted in the Department of Prosthodontics at KIMS Dental College and Hospital, Amalapuram, Andhra Pradesh, India. Ethical Review Board for clinical trials (Material protocol no. 020/ KIMS DENTAL/2022). The study was conducted in the month of June and July of 2022 year. A total of 252 samples were fabricated with VSE impression material and divided into two groups for antimicrobial activity (Staphylococcus aureus, Pseudomonas aeruginosa, and the fungus Candida albicans) and physical properties (dimensional stability, flow, setting time) with 126 samples in each group, respectively. The sample size was estimated using G Power One software with a power of 91% and an alpha error of 5%. Antimicrobial activity was determined using the disk diffusion method, dimensional stability was determined with a stereomicroscope, setting time with a Gillmore apparatus, and flow with a vernier caliper. Data were subjected to one-way Analysis of Variance (ANOVA) (p-value <0.05), T tests, and Tukey post-hoc tests, respectively. A p-value of ≤0.05 was considered statistically significant. Results: Significant changes were noted against Staphylococcus aureus bacteria when VSE was incorporated with 2.5% zinc oxide nanoparticles (p-value=0.010). The highest setting time was found for 2.5% chitosan, and the lowest setting time was for 2.5% zinc oxide (p-value <0.001). Decreased flow was observed with 2.5% chitosan, whereas increased flow was observed with 1% and 2.5% of zinc oxide nanoparticles (p-value=0.016). Enhanced dimensional stability was seen when the impression material was incorporated with 1% and 2.5% of ZnO nanoparticles (p-value <0.001). Conclusion: Based on this in-vitro study, zinc oxide and chitosan nanoparticles can be incorporated into VSE impression material as antimicrobial agents without adversely affecting their properties. [ABSTRACT FROM AUTHOR]

Preliminary impressions must record the periphery and height of maxillary defects to allow for an eventual extension of the master impression tray. These impressions are usually made with irreversible hydrocolloid. Carrying the impression material into the defect can be complex, especially in the case of a limited oral opening. Moreover, the patient can be harmed during the removal procedure, and material may be stuck in anatomical structures. The technique presented in this article avoids these issues in any maxillary defect with a two‐step preliminary impression. An elastomeric material ball is first placed in the defect until full setting. Then, this "obturator bulb" is removed and eventually relined until it is retentive. Retentions are designed on the oral side of the bulb and the bulb is placed back into the defect. Finally, an alginate over‐impression of the maxillary is made. The alginate is removed after full setting, and the obturator can be reassembled on the maxillary impression to provide a full recording of the maxillary. This protocol can safely be used for defects of any size, despite eventual limitations in oral opening. [ABSTRACT FROM AUTHOR]

This manuscript introduces a novel two-step technique for fabricating mobile dentures post-extraction to streamline prosthodontic rehabilitation. The study utilizes various materials, including dental polymers, metals, ceramics, and composite materials, each chosen for their unique properties that contribute to the final prosthesis's functionality, durability, and esthetics. The detailed procedure involves an initial occlusal registration immediately following tooth extraction, capturing precise occlusal relationships and a comprehensive dental impression. This approach reduces clinical visits and leverages optimal alveolar ridge morphology. The expected results highlight the efficiency of the technique, reducing treatment time without compromising quality and potentially improving patient satisfaction and prosthodontic outcomes. This innovative method conclusively promises rapid, efficient, and patient-centered dental rehabilitation, emphasizing the need for future research to validate its effectiveness and explore long-term outcomes. [ABSTRACT FROM AUTHOR]

Background: Vinyl polyether silicone (VPES) is a novel impression biomaterial made of a combination of vinyl polysiloxane (VPS) and polyether (PE). Thus, it is significant to assess its properties and behaviour under varied disinfectant test conditions. This study aimed to assess the dimensional stability of novel VPES impression material after immersion in standard disinfectants for different time intervals. Methods: Elastomeric impression material used –medium body regular set (Monophase) [Exa'lence GC America]. A total of 84 Specimens were fabricated using stainless steel die and ring (ADA specification 19). These samples were distributed into a control group (n=12) and a test group (n=72). The test group was divided into 3 groups, based on the type of disinfectant used - Group-A- 2% Glutaraldehyde, Group-B- 0. 5% Sodium hypochlorite and Group-C- 2% Chlorhexidine each test group was further divided into 2 subgroups (n=12/subgroup) based on time intervals for which each sample was immersed in the disinfectants – subgroup-1- 10 mins and Subgroup 2- 30 mins. After the impression material was set, it was removed from the ring and then it was washed in water for 15 seconds. Control group measurements were made immediately on a stereomicroscope and other samples were immersed in the three disinfection solutions for 10 mins and 30 mins to check the dimensional stability by measuring the distance between the lines generated by the stainless steel die on the samples using a stereomicroscope at x40 magnification. Results: The distance measured in the control group was 4397.2078 µm and 4396.1571 µm; for the test group Group-A- 2% Glutaraldehyde was 4396.4075 µm and 4394.5992 µm; Group-B- 0. 5% Sodium hypochlorite was 4394.5453 µm and 4389.4711 µm Group-C- 2% Chlorhexidine was 4395.2953 µm and 4387.1703 µm respectively for 10 mins and 30 mins. Percentage dimensional change was in the range of 0.02 – 0.25 for all the groups for 10 mins and 30 mins. Conclusions: 2 % Glutaraldehyde is the most suitable disinfectant for VPES elastomeric impression material in terms of dimensional stability and shows minimum dimensional changes as compared to that of 2% Chlorhexidine and 0.5% Sodium hypochlorite. [ABSTRACT FROM AUTHOR]

Background: There is limited literature available comparing the accuracy of intraradicular impressions made with a novel hybrid impression material using the indirect and direct technique at three different locations. Materials and Methods: For this comparative in vitro analysis, postspace was prepared in 15 recently extracted teeth and impressions made with vinyl polysiloxane, polyether (PE), vinyl polyether silicone (VPES), and pattern resin. Postpatterns obtained were re-seated on the teeth and longitudinally sectioned.A binocular microscope was used to measure apical and lateral discrepancies at three locations (LI, L2, and L3). LI at the postcore junction, L2 at the middle of the post space, and L3, 2 mm short of the apical end. The data obtained were statistically analyzed using the Statistical Package for the Social Sciences (SPSS) software. One-way analysis of variance (ANOVA) (intergroup) followed by Tukey's post hoc test with P < 0.05 was used. Results: The one-way ANOVA noted a highly significant difference at the apical location. Pattern resin had the highest apical discrepancy (151.93 ± 8.59 µm), whereas the lowest was with vinyl PE silicone (140.31 ± 11.46 µm). At LI, the highest discrepancy was seen with pattern resin (32.09 ± 2.31 µm), whereas the lowest was with the addition silicone (31.94 ± 2.54 µm). At L2, addition silicone (32.88 ± 2.81 µm) showed the highest discrepancy, whereas the lowest was with vinyl PE silicone (30.5 ± 8.79 µm). The PE group had the highest mean at the L3 location (31.38 ± 3.46 µm) and the lowest was with vinyl PE silicone (30.93 ± 2.25 µm).At all lateral locations, no significant difference was noted. Tukey's post hoc comparison showed a significant difference between pattern resin and VPES (11.62 µm) followed by pattern resin and addition silicone (11.47 µm) apically. Conclusion: The indirect technique using VPES or addition silicone is more accurate than the direct technique at the apical location. [ABSTRACT FROM AUTHOR]

Introduction: Cleft lip‐palate is the most common craniofacial congenital anomaly. Patients with Cleft lip palate require treatment with a multidisciplinary approach from birth to enable independent feeding and physiological growth. In the past, the fabrication of therapeutic devices for a child with a cleft lip palate was executed through conventional dental impression materials , with the risk of suffocation. The use of a digital workflow minimizes impression‐related risks and streamlines procedures. Methods: This study aims to propose a hybrid workflow that can combine the advantages of digital workflow with the advantages of analog workflow that can be applied daily by clinicians treating cleft lip‐palate‐affected patients. Results: The device created was immediately accepted by the patient allowing autonomous nutrition. Evaluation of the effectiveness of the device was done by body weight assessment every 15 days. Conclusion: The patient had growth comparable to that of a child born healthy. [ABSTRACT FROM AUTHOR]

Objectives: Some small defects may remain in the impression after making a two-step putty-light body impression. The aim of this study was to evaluate and compare the dimensional accuracy of 2-step and relined 2-step (3-step) puttylight body impressions. Materials and Methods: In this in vitro study, 30 impressions were made with putty, light body, and extra-light body addition silicone materials using the 2-step and 3-step impression techniques (N=15). An epoxy resin master model was made duplicating a maxillary typodont with left first premolar and first molar teeth prepared with a shoulder finish line and truncated pyramidalshaped indices in the mid-palate and third molar sites. In addition to creating a reference digital model by scanning the master model, 30 master casts were scanned to produce digital models. The anteroposterior (AP) and cross-sectional (CS) dimensional accuracy of the models were compared with the master model using linear measurements. Moreover, tooth size measurements were made and compared using the root mean square (RMS). Two-sample t-test was applied to analyze the data (a=0.05). Results: The mean AP and RMS differences between the two study groups were not significant (P>0.05). However, the CS difference between the two groups was significant (P<0.001), and the 3-step impression technique showed smaller discrepancies in comparison to the master model. Conclusion: There was no significant difference in accuracy of the two techniques for single-unit and multiple-unit preparations. The 3-step impression technique had a higher CS dimensional accuracy. [ABSTRACT FROM AUTHOR]

To evaluate the mechanical properties of a newly formulated vinyl polysiloxane (VPS) impression material. Materials and Methods: Experimental, Capture (S&C Polymer), Express, Imprint 3 and Imprint 4 (3M ESPE), Start VPS (Danville), Honigum (DMG), Virtual (Ivoclar Vivadent), Elite HD+ (Zhermack) were evaluated for tear strength, tensile strength, and elongation at break. Un-nicked specimens with a 90° angle on one side (type C) for tear strength were prepared and tested according to ASTM-D624. Dumbbell-shaped specimens (type 1) for tensile strength and elongation at break were prepared and tested according to ISO 37. All tests were carried out at 500 mm/min on a Shimadzu (AGS-X-10 KN-table top) tester. A one-way analysis of variance (ANOVA) was used to analyze the data. Results: Experimental material showed significantly higher or higher tear strength and elongation at break compared to other impression materials for both light body (LB) and heavy body (HB). For tensile strength, Experimental is similar to most impression materials; however, significantly lower than Imprint 3 and Start VPS for LB. This parameter for HB is higher or significantly higher than other impression materials except Start VPS. Tear strength and tensile strength were not correlated for LB but have a weak or moderate correlation for HB. Elongation at break is inversely proportional to tensile strength moderately for LB; however, there is no or very weak relation for HB. Conclusions: Experimental VPS impression material demonstrated a significantly higher tear strength and adequate tensile strength with higher elongation compared to other commercially available VPS impression materials. Adequate mechanical properties can provide accurate impressions for successful clinical fabrication of restorations. Experimental VPS impression material is suitable for use in dental impressions for fabrication of restorations. [ABSTRACT FROM AUTHOR]

Loss of retention and progressive ridge resorption are frequently linked to traditional mandibular complete dentures. Overdenture patients have reported great success with dental implants placed in the anterior jaw. It has been used to increase patient satisfaction as well as mandibular denture retention. Instead of using four implants and a bar to retain the overdenture, edentulous individuals are sometimes treated with just two implants and ball attachments due to their excellent success rates and cheaper costs. This article describes a straightforward procedure that houses the retentive materials directly into the impression surface of the denture utilising a chairside method, turning a current conventional denture into an implant supported overdenture. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate intraoral scanners, scannable impression materials, and conventional methods for impression-taking with regard to precision and accuracy. Materials and Methods: Ten impressions per technique were initially taken from a cobalt-chromium (Co-Cr) master model (chamfer preparation for the maxillary right first molar) for fabricating Co-Cr crown copings. The test specimens, their respective metal master model, and the plaster casts from the conventional impressions were then digitized with the lightoptical Atos Triple Scanner. The fit of the dental crown copings was measured in two and three dimensions using computer-aided design software. Global differences between the methods were determined using Kruskal-Wallis test, and pairwise comparisons were performed with Mann-Whitney U test. The significance level was set at .05. Results: The 2D analysis showed that the average absolute marginal distance of the crown copings was 0.026 mm when fabricated with the digital impression method and 0.038 mm when fabricated with the conventional method (P = .028). However, the 3D analysis revealed that the conventional group had a smaller marginal gap (0.028 mm) compared to the digital group (0.06 mm; P = .015). Conclusion: This study showed that, in the field of single-crown prosthetics, digital impressions and the use of scannable impression material could serve as alternatives to conventional methods in the future. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study was to evaluate the impression accuracy of two implants placed in different orientations and compare the impression accuracy obtained with the dual-arch impression technique using hybrid impression copings and the conventional open-tray impression technique. Materials and Methods: Five mandibular dentiform models were prepared by placing implants in the second premolar and second molar regions in the following different orientations: parallel to each other; 15-degree mesiodistal angulation; 30-degree mesiodistal angulation; 15-degree buccolingual angulation; and 30-degree buccolingual angulation. After making 10 impressions for each model with the open-tray impression technique and dual-arch impression technique with hybrid impression copings, cast models were fabricated for each impression (n = 10). Scan bodies were mounted on the five dentiform models and the fabricated 100 cast models were scanned using a desktop scanner. The three-dimensional deviation of the scan bodies on the cast models was calculated and compared to the reference data from the dentiform models. A two-way analysis of variance was conducted (α = .05). Results: The root mean square deviation values obtained from the implants placed with 30-degree mesiodistal angulation were 93.05 ± 6.21 µm with the open-tray impression technique and 104.01 ± 8.89 µm with the dual-arch impression technique, which were the largest deviation values for both techniques (P < .001). Compared to the open-tray impression technique, the dual-arch impression technique with the hybrid impression copings showed significantly lower accuracy when the angulation between the implants was 15 degrees mesiodistally (P < .001), 30 degrees mesiodistally (P = .016), or 30 degrees buccolingually (P < .001). However, there was no significant difference between the accuracy of the two impression techniques for parallel implants (P = .74). Conclusion: When the two implants were inclined 30 degrees mesiodistally, both implant impression techniques showed the largest deviation and the dual-arch impression technique showed lower accuracy compared to the conventional open-tray impression technique. Parallel placement of implants may improve impression accuracy and enable use of the dual-arch impression technique. [ABSTRACT FROM AUTHOR]

Background: Dental casts made utilising digital workflow are becoming more common because to their speed and cost savings. However, studies on their dimensional accuracy over time with diverse designs are missing. Objective: The aim of this in vitro study was to assess the dimensional stability of 3D-printed edentulous and fully dentate hollowed maxillary models with 50-micrometer resolution over 1 day, 14 days, and 28 days using surface matching software. Methods: Scanned edentulous and fully dentate maxillary typodont models were used as references. The models were scanned by a desktop lab scanner of 15-micrometer accuracy (D900, 3Shape). Then, the files were used in designing software (Meshmixer, Autodesk) to create hollowed maxillary casts. Fifteen edentulous and 15 fully dentate (total of 30) models were printed using a DLP lab printer (Cara print 4.0, Kulzer). The 3D-printed models were scanned using the same desktop lab scanner of 15-micrometer accuracy at intervals of baseline days, 1 day, 14 days, and 28 days to assess the effect of aging (n = 120). The dimensional changes were quantified and compared using the root mean square (RMS) method, expressed in micrometres (µm). The study employed repeated measures analysis of variance (ANOVA) to assess and compare the root mean square (RMS) values across the variables. The data was analysed using SPSS (26, Chicago, Illinois, USA). Results: The RMS of the edentulous models rapidly increased from a mean value of 0.257 at the beginning of the study to 0.384 after twenty-eight days. However, the mean RMS values for the dentate models did not change much over the four intervals. It varied only from 0.355 to 0.347. The mean values for edentulous patients increased from 0.014 to 0.029 during the period from baseline to twenty-eight days. However, the mean average values decreased for the dentate models from 0.033 to 0.014 during this period. By utilizing ANOVA, mean RMS values increased insignificantly till one day but significantly to fourteen and twenty-eight days. Dentate model mean values differed insignificantly across four intervals. Repeated measures ANOVA for combined and separated data showed no significant differences across edentulous, dentate, and total models over times. Conclusion: The study revealed changes in the dimensions of 3D-printed edentulous models over a span of 3 and 4 weeks. Caution should be applied when using 3D-printed dental master models for constructing definitive prostheses on edentulous models over a period of 3 to 4 weeks. [ABSTRACT FROM AUTHOR]

This study presents a methodology to prevent the overdesign of electric dispensers for dental impression materials by analyzing the necessary load and determining the appropriate pressurization speed and drive motor capacity. We derived an equation to calculate the required torque and rotational speed of the motor based on the extrusion load and the speed of the impression material. A specialized load measurement system was developed to measure the load necessary to extrude the impression material. Through experiments and image processing, we measured the radius of curvature of the trajectory of the impression material and correlated it with the pressurization speed. Techniques such as position coordinate plotting, curve fitting, and circle fitting were employed to determine the pressurization speed that aligns with the manufacturer's recommended curvature radius. These findings led to a substantial decrease in the necessary motor torque and rotational speed compared with the current standards. This research provides a systematic approach to sizing drive motors using extrusion load and pressurization speed, aiming to reduce overdesign, power consumption, and the weight and size of the motor and battery, thereby contributing to the development of more efficient and compact dental impression material dispensers. [ABSTRACT FROM AUTHOR]

The impression materials utilized today in dental medicine offer a good reproducibility and are easily accepted by patients. However, because they are polymer-based, they have issues regarding their dimensional stability. In this respect, the present work proposes a new type of dental impression, which is reinforced with rigid mouthguards. The aim of the study is to test the performances of such new impressions by comparing them to conventional ones—from this critical point of view, of the dimensional stability. Three types of polymeric materials were considered for both types of impressions: alginate, condensation silicone, and addition silicone. In order to obtain the new type of impressions, a manufacturing technique was developed, comprising the following phases: (i) conventional impressions were made; (ii) a plaster model was duplicated, and 15 rigid mouthguards were obtained; (iii) they were inserted in the impression technique, with each mouthguard positioned on the cast before the high-consistency material was inserted in the tray and the practitioner took the impression; (iv) the mouthguard remained in the tray and the low-viscosity material was inserted over the mouthguard; (v) the impression was positioned on the model, and after the material hardened, the mouthguard-reinforced impression was analyzed. In the evaluation of the dimensional stability, rigorous statistical analysis was essential to discern the performance differences between conventional and mouthguard-reinforced dental impressions. Statistical analyses employed non-parametric Mann–Whitney U tests because of the non-normal distribution of the data. They indicated a statistically significant improvement in the dimensional stability of addition silicone impressions when reinforced with mouthguards (p < 0.05), showcasing superior performance over conventional methods. Conversely, alginate and condensation silicone reinforced impressions did not exhibit the same level of stability improvement, suggesting the need for further optimization of these materials. In conclusion, from the three considered elastomers, addition silicone was found to be the prime candidate for high-precision dental impressions, with the potential to improve their quality from conventional impressions by utilizing the proposed reinforcing technique. [ABSTRACT FROM AUTHOR]

The possibility of using unmalted millet with the help of the enzymes for the production of gluten-free beer was investigated. The enzymes under different conditions were examined to completely saccharify the wort. The optimal conditions for enzymes activity were 85 °C 60 min for amylosubtilin and 60 °C 60 min for glucavamarin and β-glucanase. Since the gluten-free beverage has no colour, roasted buckwheat and boiled coffee as colourants were used. Sample with 30% roasted buckwheat showed good results in colouring the drink and had the best overall impression. Gluten-negative results were obtained for beer samples and all ingredients separately. Nevertheless, further improvements in brewing methods of gluten-free beer are needed. Almost all samples tasted more like cider than beer, without foam and with low pH values (3.5–3.8). The production of gluten-free beer provides an opportunity to attract new customers with gluten intolerance. Imperfect competition is a great advantage for manufacturers. [ABSTRACT FROM AUTHOR]

Aim: The study's objective was to assess the dimensional accuracy of hybrid polyether and polyvinyl siloxane materials for implant impressions. Materials and Methods: Nine groups were created from 45 samples of various building materials and construction techniques from the study. Five samples were tested, and 45 impressions were recorded. Results: The hybrid non-splinted technique has improved implant site replication, accuracy, and low interimplant distance alterations. Conclusion: The finest possible reproduction of implant sites on the master cast was made feasible by the use of an open, non-splinted method and a hybrid polyvinyl siloxane–polyether impression material. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this systematic review and meta-analysis was to evaluate the effects of splinting impression copings on the accuracy of conventional impressions for two-unit nonparallel implant restorations. Materials and Methods: MEDLINE via PubMed, Embase, and Web of Science databases were searched with no publication year or language limits, and studies comparing the accuracy of conventional impressions for two-unit nonparallel implant restorations made using splinted impression copings and nonsplinted impression copings were identified. A metaanalysis was performed using Review Manager software. The mean difference (MD) with 95% confidence interval (95% CI) for the framework strain and marginal gap of the implant-framework connection between impressions using splinted and nonsplinted copings were statistically analyzed (a = .05). Results: Initially, 142 articles were identified after the removal of duplicates. Five in vitro studies were included in the systematic review, and four in vitro studies were included in the meta-analysis. All the included studies were focused on internal-connection implants and implant-level impressions. The implant angulation in the included studies ranged from 8 to 30 degrees. Impressions using splinted impression copings exhibited significantly smaller marginal gaps than those using nonsplinted impression copings (P = .02; mean difference [MD] = -13.34; 95% CI = -24.31 to -2.36). Moreover, with respect to the framework strain, no significant differences were found between impressions using splinted impression copings and nonsplinted impression copings (P = .47; MD = -12.64; 95% CI = -47.32 to 22.03). Conclusions: Significantly larger marginal gaps were found in the impressions using splinted impression copings, but the clinical significance was low. Based on the limited number of studies included, splinting copings is unnecessary when making conventional impressions for two-unit nonparallel implant restorations. [ABSTRACT FROM AUTHOR]

Objective: To evaluate, in vivo, trueness and precision of two intraoral scanners, CEREC Omnicam (OMNI) and CEREC Primescan (PRIM), compared to a conventional impression serving as a master model. Method and materials: Impressions were performed for seven participants. For each participant, conventional polyvinylsiloxane impression and digital impressions using two intraoral scanners, OMNI (software 4.6; CEREC ORTHO Protocol) and PRIM (10 digital impressions per participant, per scanner), were made. Conventional impression was digitized with a laboratory scanner (INEOS X5), and used as reference model. .STL files were superimposed with software (Geomagic Control X) using the tools Initial Alignment and Best Fit Alignment, and trueness and precision were evaluated. Statistical evaluation was performed with Shapiro-Wilk and Mann-Whitney tests (P < .05). Results: Total mean trueness for the OMNI system was 56.45 ± 7.80 µm, and 47.29 ± 5.47 µm for the PRIM system. Regarding precision, values from the OMNI system were 42.47 ± 6.91 µm and from the PRIM system 21.86 ± 4.40 µm. PRIM presented better results for both trueness (P = .000) and precision (P = .000) when compared to OMNI. Conclusions: PRIM provided a better combination of trueness and precision than its predecessor OMNI. However, both PRIM and OMNI performed acceptably when performing indirect restorations, according to the current acceptable thresholds, considering both trueness and precision. Clinical implications: Fullarch impressions with Primescan presented more precision and trueness than Omnicam; however, compared to previous reported values of conventional impressions, they still presented lower accuracy. [ABSTRACT FROM AUTHOR]

Registration of the denture bearing area is an essential step for a successful rehabilitation of complete edentulism. Traditionally, it is performed using different materials and techniques, for the moment methods based on muscles functional molding being preferred. As a consequence of the development of digital techniques, a new possibility for the registration of supporting structures emerged. The digital impression uses intraoral camera and offers precise details of the denture bearing area, but without the possibility of the functional registration of the marginal area. For the moment, the association between the traditional and digital techniques seems to be the ideal solution for a perfect registration of the denture bearing area in edentulous patients. [ABSTRACT FROM AUTHOR]

Objective: To report a novel digital workflow to replace an anterior maxillary tooth lost due to trauma with an implant multilayer restoration by using the patient's extracted tooth as a final crown restoration using computer‐aided design/computer‐aided manufacturing (CAD/CAM) technology. Clinical Considerations: Instead of using the patient's natural tooth as an immediate provisional restoration to achieve predictable results in terms of esthetics and soft tissue structure, a novel digital strategy was performed to obtain a natural final crown restoration by using the patient's tooth associated with a lithium disilicate customized implant abutment. Conclusions: The perspective of using this strategic approach for implant restorative dental treatments in patients with traumatic root fractures in the anterior region has great potential as it helps to maintain the emergence profile of the natural dentition and esthetics. Clinical Significance: Optimal esthetic outcomes are challenging in implant dentistry regarding soft tissue structure and morphology factors. Using natural teeth from surgery to deliver the final restoration might be beneficial when an anterior tooth is lost due to trauma. [ABSTRACT FROM AUTHOR]

Gingival retraction is commonly employed in dentistry. There are several methods that may be used, which fall into mechanical, chemo-mechanical and surgical techniques. The application of these methods depends on the clinical activity the clinician is performing, and there are advantages and disadvantages to each method. This review reflects on the current literature available on gingival retraction methods to provide clinicians with guidance on which methods to consider when undertaking the three most common clinical scenarios: master impression taking; cementation of indirect restorations whether tooth or implant retained; and for direct adhesive dentistry. CPD/Clinical Relevance: Selecting an appropriate gingival retraction method, for example for master impression taking, cementation of restorations and in adhesive dentistry is of value. [ABSTRACT FROM AUTHOR]

Alginate impression materials in dentistry are used to form details of the oral cavity organs. The alginate content in the impression material functions to form a gel. One source of alginate is algae. Objective: This study aims to determine the recovery elasticity and setting time of alginate impression materials made from red algae K. alvarezii. Methods: The sodium alginate in the composition of this alginate impression material was extracted from red algae K. alvarezii. The alginate impression material was tested for setting time and recovery elasticity and compared with commercial impression material (Hygedent®). Results: The elastic recovery of red algae sodium alginate impression materials was 97.43% which was not significantly different from the commercial impression materials (98.42%). These results showed that this alginate impression material has the same properties as commercial impression materials. In the setting time test, the the red algal alginate impression material was much longer than the commercial impression material, 1.39 m and 3.30 m respectively. Conclusion: It was concluded that the alginate impression material from the red algae K. alvarezii had a long setting time. At the same time, the recovery of elasticity did not differ from that of commercially available alginate impression materials. [ABSTRACT FROM AUTHOR]

Objective: In this case report, we employed an admix material to record the neutral zone in a patient presenting with a palatal fistula and an atrophic mandibular ridge. Case report: In this case report, we present a 67-year-old edentulous female with a history of oropharyngeal carcinoma affecting the soft palate. A circular palatal fistula, measuring approximately 8mmx8mm, was identified at the junction of the hard and soft palate. The mandibular residual ridge displayed significant atrophy. The neutral zone was recorded using admix material, comprising three parts by weight of impression compound and seven parts by weight of tracing compound. The fabricated dentures yielded favorable outcomes in terms of denture stability, and patient comfort. The patient reported the absence of nasal regurgitation and a notable improvement in speech production due to the obturator prosthesis. Conclusion: The neutral zone impression technique with admix impression material provided successful results in constructing both a mandibular complete denture and a maxillary denture with an obturator. The retention and stability of the complete denture were desirable and the patient was satisfied with the outcome. [ABSTRACT FROM AUTHOR]

Background: The utilization of splinting techniques for impression copings is commonly advised for complex implant-supported prostheses, as it can enhance the fit of these prostheses. However, there is limited understanding regarding the impact of the secondary splinting of implant analogues, on the passive fit of the prostheses. Limited data are available on the secondary splinting of implant analogues before pouring the impression and its comparison with the primary technique of intraoral splinting of impression copings prior to impression making. Objectives: This study's objective was to determine the impact of the primary versus secondary impression splinting techniques using resin on the passive fit of screw-retained prosthesis. Material and methods: This randomized clinical trial (RCT) involved two parallel groups consisting of 14 completely edentulous patients, with seven patients in each group. Each patient received a total of eight implants, four implants per arch, resulting in a total of 28 screw-retained prostheses. Two different impression splinting techniques were employed. Group (1) utilized the primary splinting technique, where the impression copings were splinted before taking the impression. In contrast, Group (2) utilized the secondary splinting technique, where the implant analogues were splinted before pouring the impression material. To evaluate the passivity of the screw-retained prostheses in both groups, a single-screw test (one-screw test) was used. Additionally, supplementary methods, including the screw resistance test, were employed. Results: The findings of this RCT revealed higher passivity scores for secondary splinting impression pouring technique with a statistically significant difference (P = 0.082). There was a 2.2-fold greater frequency of non-passivity in the primary splinted method. In group (2), the likelihood of non-passivity was four times higher for upper arches prostheses, while there was no significant difference (P = 0.5) observed in both groups for lower arches prostheses. Conclusions: The study found that using the secondary splinting impression pouring technique resulted in greater passivity of the implant prostheses compared to the primary splinting impression technique. [ABSTRACT FROM AUTHOR]

Objectives: Disinfection of alginate impression materials is a mandatory step to prevent cross-infection in dental clinics. However, alginate disinfection methods are time-consuming and exert a negative impact on accuracy and mechanical properties. Thus, this study aimed to prepare disinfecting agents (CHX and AgNO3) and silver nanoparticles reduced by a natural plant extract to produce a self-disinfecting dental alginate. Methods: Conventional alginate impression material was used in this study. Silver nitrate (0.2% AgNO3 group) and chlorohexidine (0.2% CHX group) solutions were prepared using distilled water, and these solutions were later employed for alginate preparation. Moreover, a 90% aqueous plant extract was prepared from Boswellia sacra (BS) oleoresin and used to reduce silver nitrate to form silver nanoparticles that were incorporated in the dental alginate preparation (BS+AgNPs group). The plant extract was characterized by gas chromatography/mass spectrometry (GC/MS) analysis while green-synthesized silver nanoparticles (AgNPs) were characterized by UV-visible (UV–vis) spectroscopy and scanning electron microscopy (SEM). An agar disc diffusion assay was used to test the antimicrobial activity against Candida albicans, Streptococcus mutans, Escherichia coli, methicillin-resistant and susceptible Staphylococcus aureus strains, and Micrococcus luteus. Agar plates were incubated at 37 ± 1 °C for 24 h to allow microbial growth. Diameters of the circular inhibition zones formed around each specimen were measured digitally by using ImageJ software. Results: Chemical analysis of the plant extract revealed the presence of 41 volatile and semi-volatile active compounds. UV–Vis spectrophotometry, SEM, and EDX confirmed the formation of spherical silver nanoparticles using the BS extract. CHX, AgNO3, and the BS+AgNPs modified groups showed significantly larger inhibition zones than the control group against all tested strains. BS+AgNPs and CHX groups showed comparable efficacy against all tested strains except for Staphylococcus aureus, where the CHX-modified alginate had a significantly higher effect. Conclusions and clinical relevance: CHX, silver nitrate, and biosynthesized silver nanoparticles could be promising inexpensive potential candidates for the preparation of a self-disinfecting alginate impression material without affecting its performance. Green synthesis of metal nanoparticles using Boswellia sacra extract could be a very safe, efficient, and nontoxic way with the additional advantage of a synergistic action between metal ions and the phytotherapeutic agents of the plant extract. [ABSTRACT FROM AUTHOR]

SUMMARY: Objective: To review the materials and fabrications methods of occlusal splints with their advantages and shortcomings and to clarify the indications for each. Background: Temporomandibular joint disorders (TMDs) encompass a range of conditions affecting the masticatory system. Occlusal splints are currently recognised as a viable option for the management of TMDs when they are adopted in conjunction with additional approaches varying from conservative procedures (counselling, biofeedback, physical therapy, pharmacotherapy) to irreversible and less conservative ones (occlusal adjustments, orthodontics, arthroscopy and surgery). These splints can vary in design, function and material. The components used to fabricate the splints must withstand occlusal forces, be aesthetically pleasing, comfortable and minimally interfering with function and phonetics. Traditional methods for fabricating splints include sprinkle‐on, thermoforming and lost wax techniques. However, with the advancement of CAD/CAM technology, additive (3D printing) and subtractive (milling) manufacturing methods expand the range of possibilities by introducing novel solutions for elaborating splints. Methods: An electronic search was conducted on PubMed using the following keywords: "occlusal splint", "guard and "materials", and "manufacturing." Thirteen in vitro publications were screened and they consisted of four clinical studies, nine reviews (three of them were systematic reviews), and five case reports. Conclusion: The choice of material is crucial for the success of splint therapy. Factors such as biocompatibility, ease of fabrication, adjustability, cost and patient preference should be considered. Newer materials and techniques are emerging because of advancements in material science and manufacturing techniques. However, it should be noted that most of the evidence is based on in vitro studies with different methodologies, limiting their validity in daily practice. [ABSTRACT FROM AUTHOR]

Featured Application: An alginate-based impression material with bacteriostatic properties for application in the production of dental prosthetics, requiring a less labour-intensive process of disinfection. Disinfection of alginate impressions used in dental prosthetics is a very problematic procedure, during which the dimensions of the obtained model can change, and it can be easily mechanically damaged. Therefore, it would be beneficial to create a material with bacteriostatic properties for this application. In this work, we investigated alginate materials with the addition of 0.25–1.0 wt% of zirconium phosphate-based ion exchange resin containing silver and compared them with commercial alginate impression products. The obtained materials passed the normative requirements of ISO 21563:2021 (setting time, elastic recovery, strain in compression, compatibility with gypsum, detail reproduction, tearing strength, and linear dimensional change) as well as bacteriostatic properties in relation to Streptococcus mutans. The newly developed alginate materials met all the properties required by the standards. Their setting time was comparable to the commercial materials, and their 24 h contraction did not exceed 1.3%. Furthermore, the tearing strength was 0.42–0.48 MPa, less than that of the comparative commercial materials (0.52–0.56 MPa). From the point of view of clinical practice, it will be possible to create an alginate material with bacteriostatic properties that will prevent the transmission of cross-infections. [ABSTRACT FROM AUTHOR]

The article focuses on the challenges posed by flabby tissue in prosthodontic treatment, particularly in edentulous patients, emphasizing the importance of achieving optimal adaptation of denture bases to underlying bone for stability and function. It discusses the prevalence of flabby ridges in the maxillary arch, the shift towards non-surgical approaches for management, and the role of customized treatment strategies and impression techniques in addressing this condition.

Objectives: The objectives of the current study was to evaluate the disinfection efficacy of ozone, ultraviolet (UV) radiation, herbal and glutaraldehyde method for sterilization of elastomeric impression materials. Materials and Methods: Disinfection of elastomeric impression material was performed with each of the disinfection methods: ozone, UV radiation, herbal, and glutaraldehyde. Later microbiological analysis was performed and the colony-forming units were evaluated and compared. Results: The highest disinfection efficacy was found with glutaraldehyde, followed by ozone and UV radiation, and the least with neem herbal rinse. Intergroup comparison was highly significant. Conclusion: Dry gaseous ozone and UV radiation can be used effectively for the disinfection of impressions. [ABSTRACT FROM AUTHOR]

Systemic scleroderma is a relatively rare, autoimmune, chronic, and debilitating disease, and its etiology is unknown. The disease is characterized by vasomotor disturbances causing skin and mucosa hardening, hand stiffness, excess production of collagen fibers, and impairment of the internal organs associated with the immune system. Extreme mouth-opening limitation is one of the symptoms in the oral cavity, and compromises dental intervention. One of the fundamental steps when performing a dental procedure is dental arch impression. In the presented clinical case, limited mouth opening hindered the impression accuracy. The objective was to present an alternative impression technique for a patient affected by scleroderma, with limited mouth opening and the need for oral rehabilitation with a removable partial prosthesis in the maxillary arch. An individualized tray was developed with design characteristics that allowed access to the oral cavity and removal, after which it was possible to perform the oral impression, reproducing the areas of interest without causing injury to the oral tissues. The orientation plan was elaborated after obtaining the cast. The teeth were assembled, tested in the mouth, and sent to the laboratory for acrylization. The prosthesis was placed once ready. The alternative impression technique enabled oral rehabilitation of the patient despite the mouth-opening limitation, and provided an accurate impression and a good prosthetic result. [ABSTRACT FROM AUTHOR]

This prospective controlled clinical trial investigated the possible correlation among mucosa thickness, mucosa height, and width of keratinized mucosa on the contour changes of the peri-implant soft tissue collar over a period of 12 months. Forty patients were selected to undergo implant placement. Impressions were taken with polyether impression material at delivery of the final restorations (baseline) and at 1, 3, 6, and 12 months. Master casts were fabricated and scanned using an indirect digitalization. Baseline and corresponding follow-up scans were then virtually superimposed and matched. At 1 year, 20 patients who received the buccal pedicle flap showed an average thickness increase of 1.49 mm (ρs = 0.95; range: 0.01 to 2.56 mm), whereas the 5 patients who received a connective tissue graft at second-stage surgery reported an average thickness increase of 0.33 mm (ρs = 0.70; range: -0.62 to 1.23 mm). Finally, the remaining 15 patients who did not receive any soft tissue grafting nor any type of plastic surgery showed an average mucosa thickness increase of 0.51 mm (ρs = 0.28; range: -2.33 to 2.52 mm). [ABSTRACT FROM AUTHOR]

The purpose of this study was to evaluate in vitro the accuracy of different splinting techniques using transfers combined with different tray types. Materials and Methods: The research group fabricated a maxillary master cast with four implants and a passive metallic bar on this master cast. For the impression techniques, 48 casts were used with six different impression techniques: (1) metal tray with resin splinted transfers, (2) metal tray with metal and resin splinted transfers, (3) plastic tray with resin splinted transfers, (4) plastic tray with metal and resin splinted transfers, (5) multifunctional guide with resin splinted transfers, and (6) multifunctional guide with metal and resin splinted transfers (n = 8) using polyvinyl siloxane impression material. This study used a passive metallic bar to measure the malalignment between the framework and the analogs (A, B, C, and D) in 2D and 3D. The master and experimental casts were scanned with a contact scanner to compare the accuracy in 3D impression techniques. Discrepancies between the analogs were measured in three x-, y-, and z-axes. Results: There was no statistically significant difference (P > .05) between the groups in vertical malalignments (2D). In the 3D evaluation, for the z-axis and combination of xz-axis, plastic tray with metal, and resin splinted transfers (z = 487 μm; xz = 888 μm), there was a statistically significant difference compared with the multifunctional guide and resin splinted transfers (z = 772 μm; xz = 1,380 μm). When analyzing by analog, in C, the multifunctional guide with metal and resin splinted transfers (302 μm) presented a statistically significant difference compared with the multifunctional guide and resin splinted transfers (492 μm). Conclusion: The evaluation methods for the accuracy impression technique presented different results between them. There was no difference in vertical malalignments (2D), but in 3D, the bonding with metal and acrylic resin presented better results than the bond with only acrylic resin when using the plastic tray and multifunctional guide, respectively, in the z-axis and the combination between the xz-axes. The bonding technique of the transfers with metal and acrylic resin presents better results in the 3D analysis for the multifunctional guide impressions. [ABSTRACT FROM AUTHOR]

Objective: This technique aims to construct a virtual, well‐adapted maxillary denture from an existing, ill‐fitting denture in completely edentulous patients. Clinical Considerations: A functional impression is made using the loose maxillary denture, and a cone beam computed tomography (CBCT) of the entire old denture is carried out. The obtained digital imaging and communication in medicine (DICOM) file was segmented using an image computing platform software (3D slicer). The resultant Standard Tessellation Language (STL) file was 3D printed in porcelain white‐like resin, then colored and characterized. Conclusions: The technique introduces a high‐quality digital denture replicate with good retention, that can replace the traditional duplication technique. It can also be used as a relining method for old dentures. This proposed digital technique reduces the number of clinical appointments while also providing a digital library for future denture manufacture. Clinical Significance: The proposed technique offers a high‐quality digital denture replicate that can replace the traditional duplication technique. This digital technique also reduces the number of clinical appointments required for denture duplication. [ABSTRACT FROM AUTHOR]

Objective: This clinical trial aims to compare the accuracy of interocclusal registration in centric relation taken with polyvinyl siloxane and intraoral scanner (IOS) with the fabrication of occlusal devices. Methods: Thirty‐one participants were included in the trial registered at ClinicalTrials.gov (NCT05317182) receiving two different occlusal devices from two different workflows. One workflow was performed using polyvinyl siloxane impression material and the other with IOS. Every splint was scanned before and after the occlusal adjustments to compare the volumetric changes using the Root Mean Square deviation (RMS). Furthermore, three evaluators assessed the 3D comparison using color maps in a Visual Analog Scale (VAS). Results: The average values of RMS were higher for the analog approach (0.01 ± 0.067) than the digital approach (0.065 ± 0.035). However, the differences were not statistically significant (p < 0.063) between the two impression techniques. For the semiquantitative analysis performed by blinded evaluators, differences in VAS values between the impression for the digital (2.08 ± 2.4) and analog (3.80 ± 3.3) technique were statistically significant. The three evaluators agreed in more than 90% of the qualitative dichotomous evaluation. Conclusion: Digital impressions did not show inferior accuracy compared to conventional impressions when assessed using quantitative measurements. Clinical Significance: This clinical trial provided evidence on registering interocclusal relationship at increased vertical dimension with fully digital workflow for complete arch prosthesis. [ABSTRACT FROM AUTHOR]

Aim: The goal of the study is to evaluate and compare the pH and dimensional stability of the experimental root sealer to those of existing root sealers commonly used in endodontic therapy. Methods: The study samples were produced using commercially available sealers as well as experimental sealers containing nanoparticles. The pH was measured using a digital pH meter (accuracy of 0.01). Before each pH measurement, the pH meter's accuracy was calibrated with a solution. Once the relevant dimension samples were generated, the dimensional stability of the materials was evaluated. L 30 - L/L × 100 was the formula used to calculate the percentage of dimensional change. Results: The Apexit Plus demonstrated a 1.33% expansion compared to the experimental sealer's 0.43%. The contraction was 0.37% for AH Plus. The mean pH of the experimental root canal sealer utilized at various periods of immediate, 24 h and 1 week after is 9.51, 8.48, and 8.17. The mean pH of the AH Plus root canal sealer immediately, 24 h and 1 week was 8.30, 7.70, and 6.80, respectively. Conclusion: Within the constraints of the studies, the experimental sealer had stronger pH and dimensional stability than commercially available sealers. In vivo studies can be performed to reassess the qualities. [ABSTRACT FROM AUTHOR]

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Dental medicine is advancing at an exceptionally fast rate, one of its main reasons being the integration of digital technologies. An example of this are intraoral scanners, which provide us with the opportunity to acquire a digital model as an alternative to conventional methods. The search was limited to full articles published in peerreviewed scientific journals. Two factors affect accuracy: trueness and precision. Trueness refers to the deviation of the scanned object from its actual geometry. Precision refers to the deviation between multiple scans. For replacing conventional impression materials and gypsum models by digital systems, they must exhibit at least the same level of accuracy/quality.At present, intraoral scanners appear as a reliable alternative to conventional methods for creating fixed restorations, on both natural teeth and implants. [ABSTRACT FROM AUTHOR]

A flabby ridge is a condition where excessively mobile and resilient tissue affects the maxillary or mandibular alveolar ridges. This study reviews the flabby anterior maxillary ridges and explores their management. It also included a case report of a 67-year-old male diabetic patient with rare manifestations in the anterior maxilla. The selection of this patient in this study was due to the rare flabby tissue manifestations in the anterior maxilla. These manifestations resulted in denture instability and loss of retention but also caused significant symptoms for the patient, including severe pain, prolonged headaches, and a burning sensation. This study aimed to alleviate pressure on the flabby tissues in the anterior maxilla and enhance the complete denture's retention, support, and stability. In managing the flabby anterior maxilla described in this study, the prosthetic approach involved utilizing a modified window technique for the secondary impression and a low-viscosity impression material. On the following day till the follow-up period (12 months), the patient showed no complaints of pain, headache, or burning sensation, and the complete denture was in good retention, support, and stability. Prosthodontic management is a reliable alternative to surgery for hypermobile flabby tissues. It improves denture quality, reduces pressure, and enhances comfort and functionality during daily activities. [ABSTRACT FROM AUTHOR]

Purpose: To assess the absolute linear distances of three different intraoral scan bodies (ISBs) using an intraoral scanner compared to a conventional impression in a common clinical model setup with a gap and a free-end situation in the maxilla.Materials and Methods: An implant master model with a reference cube was digitized using x-ray computed tomography and served as the reference file. Digital impressions (TRIOS, 3Shape) were taken using three different ISB manufacturers: NT Trading, Kulzer, and Medentika (n = 10 per group). Conventional implant impressions were taken for comparison (n = 10). The conventional models were digitized, and all models (digital and conventional) were superimposed with the reference file to obtain the 3D deviations for the implant-abutment-interface points (IAIPs). Results for linear deviation (trueness and precision) were analyzed using pairwise comparisons (P < .05; SPSS version 25). For precision, a two-way factorial mixed ANOVA was used.Results: The deviations for trueness (mean) ± precision (SD) of the IAIPs ranged as follows: FDI region 14 = 0.106 ± 0.050 mm (Medentika) to 0.134 ± .026 mm (NT Trading); region 16 = 0.108 ± 0.046 mm (conventional) to 0.164 ± 0.032 mm (NT Trading); region 24 = 0.111 ± 0.050 mm (conventional) to 0.191 ± 0.052 mm (Medentika); region 26 = 0.086 ± 0.040 mm (conventional) to 0.199 ± 0.066 mm (Kulzer). There were significant differences for trueness between all digital and conventional impression techniques. For precision, only two significant differences in two implant regions (14, 24) were observed.Conclusion: Longer scanning paths resulted in higher deviations of the implant position in digital impressions. Due to algorithms implemented in the software, errors resulting from the different scan bodies may be reduced during the alignment process of the IOS in clinical practice. [ABSTRACT FROM AUTHOR]

The rehabilitation of patients with wear on multiple teeth, in which a recovery of the occlusal/incisal vertical dimension is required to acquire satisfactory levels of functionality and esthetics, is often a difficult procedure even for experienced dental practitioners. Based on wax-ups simulating an ideal structural/functional reconstruction of the teeth, the use of shaping indices is a reliable way to plan predictable patient-oriented results when using resin-based composites. The proposal to combine shaping indices with PTFE-based stamp techniques also helps clinicians to easily achieve satisfactory modeling results giving them the unique opportunity to eliminate the presence of composite over-contours before polymerization. By using PTFE-based stamps the requirement to use conventional, strictly transparent indices becomes superfluous. In a clinical case with multiple caries lesions and tooth wear, the advantage of several simple operative measures including PTFE-based stamp procedures are presented as a feasibility example of this noninvasive or minimally invasive restorative approach performed by an undergraduate dental student. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the dimensional accuracy of impressions made using a new fast-setting polyether material.Materials and Methods: A metallic reference model with two crown preparations, one inlay preparation, and three stainless steel precision balls was digitized to create a digital reference model. Sixteen one-step impressions were made for each of the four study groups, differing in impression material (regular-setting polyether [RSP] vs fast-setting polyether [FSP]) and technique (monophase vs dualphase), for a total of 64 specimens. Plaster casts fabricated from these impressions were digitized using 3D scans. Global accuracy was studied by evaluating distance and angle deviations between the replica and the reference model. Local accuracy was described in terms of trueness and precision of the aligned individual abutment tooth surfaces.Results: For all impression materials and techniques, the local accuracy at the abutment tooth level was excellent. For surfaces prepared for crowns, mean trueness was < 10 μm, and mean precision < 12 μm. Inlay surfaces were associated with higher inaccuracies (mean trueness < 21 μm and mean precision < 37 μm). The greatest global inaccuracies were generally measured for the cross-arch span, with mean distance changes between -55 μm and -94 μm. For all aspects of studied accuracy, impressions with FSP were at least comparable to those fabricated with RSP.Conclusion: Within the limitations of this study, all tested polyether materials would allow for clinically acceptable impression making. The new fast-setting material could be an alternative to regular-setting polyether materials, especially for single crowns and small fixed partial dentures. [ABSTRACT FROM AUTHOR]

Purpose: To determine the accuracy of direct digital impressions in vivo and compare it to that of conventional impressions in order to assess whether intraoral scanners could be a legitimate alternative for the manufacturing of fixed prosthodontics.Materials and Methods: An electronic systematic search was conducted in the PubMed, Web of Science, Embase, and Cochrane Library databases using query terms such as digital impression; intraoral digital impression; intraoral scanner; intraoral digital scanner; conventional impression; analogue impression; and accuracy. The outcomes were the trueness and precision of digital impressions in comparison to those of high-precision conventional impressions in vivo.Results: Six studies matched the inclusion criteria. Four studies investigated the precision of digital impressions, while two studies focused on their trueness. Even if all the authors agreed that conventional impressions were more accurate than digital impressions in vivo, they gave different opinions on using intraoral scanners in a clinical context without causing misfit of the final restoration.Conclusion: According to the results of the present review, conventional impressions performed using high-precision impression materials showed greater accuracy than digital impressions. However, additional studies assessing the accuracy of digital impressions in a wider variety of clinical situations are highly recommended. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the effects of aluminum chloride based hemostatic agents on the surface detail reproduction and dimension stability. Three impression materials were investigated after contaminated with three commercial astringents with different concentration of aluminum chloride. The specimens from three impression materials were fabricated with a stainless-steel mold that followed the American Dental Association specification no.19. The mold was preliminarily contaminated with three hemostatic agents racestyptine, Dryz, and Expasyl™—and 80 specimens from each impression material—polyvinylsiloxane (PVS), polyether, and polyvinylsiloxane ether (PVSE), were fabricated and subjected to each astringent. The surface detail reproduction was examined using a stereomicroscope at 4x magnification, and the dimensional stability was analyzed at 24 hr with a measuring microscope. The surface detail data were statistically analyzed with Fisher's test at a significance level of 0.05. The dimensional stability data were analyzed using two-way ANOVA and Tukey's test at a significance level of 0.05. Aluminum chloride hemostatic agents can affect the surface detail reproduction of impression materials differently (p < 0.05). Thus, the first null hypothesis was rejected. PVS showed the highest percentage of satisfactory surface detail regardless of the hemostatic agent used in this study. PVSE showed a reduced percentage of satisfactory surface detail when the concentration of aluminum chloride was high. The three hemostatic agents affected the dimensional stability of each material differently (p < 0.05). Therefore, the second null hypothesis was also rejected. [ABSTRACT FROM AUTHOR]