Statement of problem Acrylic denture base resins are subject to colonization by oral and nonoral bacteria, contributing to the onset of denture stomatitis. However, how the addition of antimicrobial substances affects the mechanical and optical properties of additively manufactured denture base resin remains unclear. Purpose The purpose of this in vitro study was to investigate the surface roughness, color stainability, and flexural strength of antimicrobial-modified, additively manufactured polymethyl methacrylate (PMMA) denture base resin in tooth and gingiva colors. Material and methods Three antibacterial agents, e-poly-L-lysine+ methacryloyloxyethyl phosphorylcholine (e-MP), silver nanoparticles (AG-P), quaternized ammonium monomer (QA-P) synthesized via the reaction of octyl bromide and DMAEMA, were separately incorporated into tooth- or gingiva-colored 3-dimensionally (3D) printable PMMA specimens, simulating an implant-supported overdenture base or the artificial teeth (n=80). Unaltered specimens served as controls. Autopolymerizing acrylic resin was used to attach titanium matrix housings to gingiva-colored specimens. All specimens underwent coffee thermal cycling (CTC) comprising 10 000 cycles between 5 °C and 55 °C, and their color coordinates were measured. Surface roughness, color change (ΔE00), and flexural strength were calculated before and after CTC. The results were analyzed and compared by using ANOVA and the Tukey post hoc test (α=.05). Results All antibacterial agent-incorporated specimens showed lower ΔE00 values than the control (P=.001), with eM-P exhibiting the least color change (P=.001). The control group had the highest post-CTC roughness (Ra) values (P<.001), while all test groups demonstrated higher flexural strength than the control (P=.001). CTC had no significant effect on flexural strength (P>.115). Conclusions The addition of antimicrobial agents to 3D printable implant overdenture base resin in tooth and gingiva color affected the materials’ surface properties, color stainability, and flexural strength. Smoother surface, lower color stainability, and higher flexural strength were observed with the addition of eM-P.

STATEMENT OF PROBLEM:Knowledge of the surface roughness and color stability of definitively intended additively manufactured (AM) resins when different postprocessing cleaning solutions and surface treatments are applied is limited. PURPOSE:The purpose of this in vitro study was to evaluate the effect of postprocessing cleaning solution and surface treatment (polishing and coffee thermocycling) on the surface roughness and color stability of resins intended for AM definitive restorations. In addition, the color coordinates were compared with an A1 shade tab. MATERIAL AND METHODS:Sixty specimens were AM from 2 different resins, a glass-filler reinforced composite resin (AM-CR) and urethane acrylate-based resin (AM-UA), for definitive restorations. The specimens were divided into 3 groups based on the postprocessing cleaning solution (n=10): 96% ethanol, water-based solvent, and methyl ether solvent. The surface roughness (Ra) and color coordinates were measured before polishing, after polishing, and after coffee thermocycling for 5000 cycles. Color difference values (ΔE00) were calculated, and color coordinates were compared with a reference shade tab (α=.05). RESULTS:AM-CR had a lower Ra with ethanol than methyl ether solvent before polishing (P=.006). AM-UA had the lowest Ra with ethanol and the highest Ra with water-based solvent before polishing (P≤.001). Irrespective of material and postprocessing solution, Ra decreased after polishing (P≤.001). AM-CR had the highest ΔE00 with methyl ether solvent after polishing and after coffee thermocycling (P≤.002). AM-CR had the lowest ΔE00 with ethanol after coffee thermocycling (P≤.003). CONCLUSIONS:Resin type, postprocessing cleaning solution, and surface treatment affected the surface roughness and color stability of AM resins intended for definitive restorations.

PURPOSE:To investigate the impact of printing layer thickness on the optical properties and surface roughness of various 3D-printed resins manufactured by digital light processing (DLP) and indicated for provisional and definitive restorations. MATERIALS AND METHODS:A total of 240 specimens from four different 3D-printing resins-VarseoSmile Crown Plus (Bego; VS), Crowntec (Saremco Dental; CR), GC Temp PRINT (GC Dental; TG), and NextDent C&B MFH (NextDent; ND)-were divided into four groups (n = 60 per group). Each group was further divided into three subgroups (n = 20) according to printing layer thickness (25, 50, and 100 μm). All specimens were subjected to thermocycling with coffee before measurements were taken with a spectroradiometer to calculate color differences. The Kubelka-Munk (K-M) absorption (K) and scattering coefficients (S), translucency parameters (TP), and surface roughness (Ra) values were calculated for each printing layer thickness and compared with those of the 2M2 shade tab (target). The data were analyzed using Mann-Whitney U test, the variance accounted for (VAF) coefficient by Cauchy-Schwarz, and post hoc comparisons using Tukey test (α ≤ .05). RESULTS:S (79% ≤ VAF ≤ 100%) and K (40.45% ≤ VAF ≤ 100%) spectral distribution depended on the wavelength. A 25-μm layer thickness resulted in no significant differences from the 2M2 shade for S (P > .230) and K (P > .200). VS showed significantly different S (P = .004) and K (P = .003) values from those of the shade tab with 50-μm layering thickness, whereas other materials did not show significant differences from the 2M2 shade for S (P > .280) and K (P > .301). The 100-μm layer thickness specimens had significantly different S and K values compared to the 2M2 shade tab (P < .004). TP values of resins with 100-μm layer thickness were significantly lower than resins in 25- and 50-μm layer thicknesses (P < .001). The Ra values of resins increased significantly with 100-μm layer thickness (P ≤ .001). CONCLUSIONS:All tested materials, except for VS, showed color properties similar to the target shade when 25- and 50-μm printing layer thicknesses were used. The translucency of resins tended toward an inverse relationship with printing layer thickness. The surface roughness of resins increased significantly with 100-μm layer thickness. However, all resins with a printing thickness of 25 μm showed better color properties and surface roughness.

PURPOSE:To assess the accuracy of complete maxillary and mandibular edentulous arch scans obtained using two different intraoral scanners (IOSs), with and without scanning aids, and to compare these results to those obtained using conventional impression methods. MATERIALS AND METHODS:Two IOSs were used (TRIOS 4 [TRI] and Emerald S [EMR]) to scan maxillary and mandibular typodonts. The typodonts were scanned without scanning aids [TRI_WSA and EMR_WSA groups] (n = 10). The typodonts were then scanned under four scanning aid conditions (n = 10): composite markers [TRI_MRK and EMR_MRK groups], scanning spray [TRI_SPR and EMR_SPR groups], pressure indicating paste [TRI_PIP and EMR_PIP groups], and liquid-type scanning aid [TRI_LQD and EMR_LQD groups]. Conventional impressions of both arches were also made using irreversible hydrocolloids in stock trays [IHC] and using polyvinyl siloxane (PVS) impression material in custom trays (n = 10) which were digitized using a laboratory scanner. Using a metrology software program, all scans were compared to a reference scan in order to assess trueness and to each other to assess precision. Trueness and precision were expressed as the root mean square (RMS) of the absolute deviation values and the statistical analysis was modeled on a logarithmic scale using fixed-effects models to meet model assumptions (α = 0.05). RESULTS:The main effect of arch (p = 0.004), scanner (p < 0.001), scanning aid (p = 0.041), and the interaction between scanner and scanning aid (p = 0.027) had a significant effect on mean RMS values of trueness. The arch (p = 0.015) and scanner (p < 0.001) had a significant effect on the mean RMS values of precision. The maxillary arch had better accuracy compared to the mandible. The TRIOS 4 scanner had better accuracy than both the Emerald S scanner and conventional impressions. The Emerald S had better precision than conventional impressions. The scanning spray and liquid-type scanning aids produced the best trueness with the TRIOS 4 scanner, while the liquid-type scanning aid and composite markers produced the best trueness for the Emerald S scanner. CONCLUSION:The scanned arch and the type of scanner had a significant effect on the accuracy of digital scans of completely edentulous arches. The scanning aid had a significant effect on the trueness of digital scans of completely edentulous arches which varied depending on the scanner used.

BACKGROUND:There is limited knowledge on the fabrication trueness and fit of additively or subtractively manufactured complete-arch implant-supported frameworks in recently introduced polymers. PURPOSE:To evaluate the trueness and marginal fit of additively or subtractively manufactured polymer-based complete-arch implant-supported frameworks, comparing with those of strength gradient zirconia frameworks. MATERIALS AND METHODS:A typodont model with 4 implants (left first molar (abutment 1), left canine (abutment 2), right canine (abutment 3), and right first molar (abutment 4)) was digitized (ATOS Core 80 5MP) and an implant-supported complete-arch framework was designed. This design file was used to fabricate frameworks from 5 different materials: strength gradient zirconia (SM-ZR), high impact polymer composite (SM-CR), nanographene-reinforced PMMA (SM-GR), PMMA (SM-PM), and additively manufactured temporary resin (AM) (n = 10). These frameworks were digitized and each scan file was virtually segmented into 4 regions (abutments, occlusal, overall without occlusal, and overall). The surface deviations at these regions, and linear and interimplant distance deviations were evaluated (Geomagic Control X). Marginal gaps were evaluated according to triple-scan protocol after seating frameworks on the model with the 1-screw test. Data were statistically analyzed (α = 0.05). RESULTS:Surface deviations of all regions differed among tested materials (p ≤ 0.001). AM frameworks mostly had surface deviations that were similar to or lower than those of other materials (p ≤ 0.031), except for the occlusal surface, where it mostly had higher deviations (p ≤ 0.013). Abutment 4 of SM-CR had higher linear deviations than abutment 2 (p = 0.025), and material type did not affect the linear deviations within abutments (p ≥ 0.171). Interimplant distance deviations differed within and among materials (p ≤ 0.017), except for those between abutments 1 and 2 among materials (p = 0.387). Marginal gaps of subtractively manufactured materials differed among abutments, while those of abutments 3 and 4 differed among materials (p ≤ 0.003). AM frameworks mostly had lower marginal gaps at abutments 3 and 4 (p ≤ 0.048). CONCLUSIONS:Although there was no clear trend among tested materials for measured deviations, marginal gaps of additively manufactured resin were mostly lower than those of subtractively manufactured materials and did not differ among abutment sites. Nevertheless, the differences in measured deviations among materials were small and marginal gaps were within the previously reported acceptability thresholds.

PURPOSE:This study evaluated the effects of artificial saliva and distilled water on the nanoindentation creep of different 3D-printed and milled CAD-CAM resin composites. MATERIAL AND METHODS:Disk-shaped specimens were subtractively fabricated from polymer-infiltrated ceramic network (EN) and reinforced resin composite (B) and additively from resin composite (C) and hybrid resin composite (VS) using digital light processing (DLP). Specimens from each material were divided into two groups according to their storage conditions (artificial saliva or distilled water for 3 months). Creep was analyzed by nanoindentation testing. Statistical analysis was done using two-way ANOVA, one-way ANOVA, Bonferroni post hoc tests, and independent t-test (α = 0.05). RESULTS:The main effects of material and storage conditions, and their interaction were statistically significant on nanoindentation (p < 0.001). Storage condition had the greatest influence (partial eta squared ηP 2 = 0.370), followed by the material (ηP 2 = 0.359), and the interaction (ηP 2 = 0.329). The nanoindentation creep depths after artificial saliva storage ranged from 0.34 to 0.51 µm and from 0.50 to 0.87 µm after distilled water storage. One of the additively manufactured groups had higher nanoindentation creep depths in both storage conditions. CONCLUSIONS:All specimens showed comparable performance after artificial saliva storage, but increased nanoindentation creep after distilled water storage for 3 months. The subtractive CAD-CAM blocks showed superior dimensional stability in terms of nanoindentation creep depths in both storage conditions. Additively manufactured composite resins had lower dimensional stability than one of the subtractively manufactured composites, which was demonstrated as having higher creep deformation and maximum recovery. However, after artificial saliva storage, one of the additively manufactured resins had dimensional stability similar to that of subtractively manufactured.

A bstract Aim: This study aims to conduct a comprehensive analysis and scientometric evaluation of the top 100 most cited publications in the field of implant prosthodontics, authored by individuals affiliated with nations of the Middle East and North Africa (MENA) region. Materials and Methods: In October 2023, the 100 most cited articles were gathered from the Web of Science database using the bibliometric research technique. The analysis was conducted on bibliometric indicators, including the distribution of articles over time, authorship, design of study, field of study, nature of research, contribution from various countries in MENA, international research collaboration, and most frequently used keywords by authors. Chi-square and one-way analysis of variance were used for statistical analysis. VOSviewer software was used to analyze the bibliometric network for co-occurrence among countries, coauthors, and common keywords. Results: The results revealed that the top 100 most cited articles from MENA countries on the topic of implant prosthodontics, published between 1995 and 2020, had received an average of 73.31 citations each. About one-third of the papers were published in the top 4 journals. The journal with the most published articles was Clinical Oral Implant Research, followed by the International Journal of Oral & Maxillofacial Implants , the International Journal of Prosthodontics , and the Journal of Oral and Maxillofacial Surgery . Saudi Arabia had the distinction of producing the greatest number of highly cited papers. The co-occurrence network analysis using VOSviewer software identified 10–15 related clusters. Research studies with multiple authors received significantly more citations ( P < 0.05). Significant relationships were observed between the number of citations and journal type (open access vs. non-open access; P < 0.05), and also articles published in dental journals received the most citations and were statistically significant ( P = 0.001). Conclusion: Over the last decade, there has been a significant surge in research related to implant prosthodontics. Among the countries in the MENA region, Saudi Arabia has distinguished itself by leading in terms of overall research output. This resource would benefit academicians, clinicians, and researchers in prosthodontics, oral surgery, and periodontic specialties of dentistry.

This case report describes a new digital workflow for computer-assisted implant surgery in an edentulous patient using transitional implants to support a fixed surgical template and interim prosthesis. The accuracy of the final implant position using the described protocol was evaluated and compared to the outcomes obtained using other types of surgical templates. This novel digital approach appears to enhance the accuracy of implant positioning for edentulous patients and seems to be comparable to a tooth-supported surgical template.

Objectives: The Level of Evidence (LOE) ranking system is used to measure the method-ological quality of research. This study aimed to analyze and evaluate the trends of LOEs in articles published in the Saudi Dental Journal (SDJ) between 2012 and 2021. Methodology: The bibliometric details of all articles published from 2012 to 2021 were extracted from the SDJ website. All articles, expect editorials, were included in the analysis. The articles were divided based on LOEs, dental specialties, number of authors, and centers. The citation metrics were obtained from Google Scholar, and the statistical analysis was performed using JMP Pro 15.2.0 software. Results: Five hundred twenty-two articles were selected for analysis. They had an average of 21.19 citations per article, and a growing trend in the number of articles was observed. Authors from 40 countries contributed to the articles, with the most contributions from the Kingdom of Saudi Arabia. Most articles (n = 269; 51.53%) were LOE IV and V, while a low proportion (5.56%) were LOE I articles. Aside from miscellaneous articles, periodontics composed most of the LOE I studies, followed by endodontics, and oral and maxillofacial Surgery (OMFS). Orthodontics had the highest number of LOE II studies, pediatric dentistry had the most LOE IV, and prosthodontics had the most LOE V studies. No significant correlations were found between LOE and the number of authors or centers. However, a significant correlation was found in the distribution of LOE contributed by academic institutes. Conclusion: The study results highlight that most articles were LOE IV and V, whereas nominal LOE I articles were found. Furthermore, there is a need to encourage dental scientists to carry out high-quality evidence studies. Professional dental societies can play a pivotal role in this regard. (c) 2023 The Authors. Production and hosting by Elsevier B.V. on behalf of King Saud University. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Provisional restoration is essential for function, esthetics, occlusion, and tissue health. However, when multiple teeth are involved, making a direct splinted provisional restoration could be challenging due to the combined undercuts between the prepared teeth. This article describes a dental technique using polytetrafluoroethylene (PTFE) tape as a spacer to fabricate a splinted provisional restoration for multiple prepared teeth. The PTFE tape spacer will compensate for discrepancies in the path of insertion between prepared teeth, thus facilitating the removal of the direct splinted provisional restoration intact.

OBJECTIVES:Registration of intra-oral surface scans to cone beam computer tomography (CBCT) is critical in the digital workflow for static computer-aided implant surgery (sCAIS). This study aimed to assess the impact of CBCT field of view (FoV) on the precision of digital intra-oral scan registration.MATERIALS AND METHODS:Cone beam computer tomography data and intra-oral scans from 20 patients were included. Small FoV CBCT's were created by digitally segmenting a large FoV into three sextants. Virtual implant planning was performed. Digital intra-oral scans were repeatedly registered onto their corresponding large and small FoV CBCT datasets. The distances and angulations between the matching implant positions of each repeated registration were used to determine the precision of the registration process. Wilcoxon Signed Rank Paired Tests were used to compare the differences between large FoV and small FoV. The threshold for statistical significance was set at p = .05.RESULTS:Differences in 3D implant position based on the registration precision between small FoV and large FoV present at both the implant entry point (0.37 ± 0.25 mm vs 0.35 ± 0.23 mm, p = .482) and implant tip (0.49 ± 0.34 mm vs 0.37 ± 0.24 mm, p < .001). Differences in overall angular precision were observed between small FOV and large FoV (1.43 ± 1.36° vs 0.51 ± 0.38°, p < .001).CONCLUSION:CBCT with a small FoV is accompanied by greater precision errors in intra-oral scan registration. However, when sufficient well-distributed teeth are visible in small FoV CBCT, the precision of digital intra-oral scan registration appears to be within clinically acceptable limits for sCAIS.

STATEMENT OF PROBLEM:The impact of discrepancies between casts produced from digital scans and conventional impressions on the clinical performance of definitive restorations has not been fully investigated. PURPOSE:The purpose of this crossover clinical trial was to evaluate the clinical performance of single implant-supported restorations fabricated with the digital scanning technique and computer-aided design and computer-aided manufacturing (CAD-CAM) casts compared with the conventional impression technique and gypsum casts in terms of efficiency, accuracy, and participant preference. MATERIAL AND METHODS:Thirty participants underwent conventional impressions and digital scans of a single implant-supported restoration. Two crowns were fabricated for the same implant with each technique. The time taken for each procedure was recorded. After the accuracy and efficiency analysis of both crowns, the better crown was delivered. A questionnaire was used to assess participant preference and comfort with the techniques. The Wilcoxon signed-rank test was used to compare the time measurements, and multiple comparisons were performed using the Bonferroni method. The chi-square test was used to compare the implant locations of delivered crowns (α=.05). RESULTS:The total time for the conventional impression technique was 14.16 minutes, while that for the digital scanning technique was significantly less at 11.28 minutes (P<.001). Remake times were 0.56 minutes for conventional impressions and 2.27 for digital scans, also significantly different (P<.001). The adjustment time taken in delivering the crowns was 4.35 minutes for conventional impressions and 3.78 minutes for conventional impressions, which was not statistically significant (P=.940). Of the crowns chosen for delivery, 46.7% were from conventional impressions and 53.3% from digital scans. Participants preferred the digital scanning technique (89%) to the conventional impression technique (11%). CONCLUSIONS:The digital scanning technique was more efficient than the conventional impression technique for single implant-supported restorations. Digital scans and CAD-CAM implant casts had accuracy comparable with that of conventional impressions and gypsum casts. Most participants preferred digital scans to conventional impressions.

OBJECTIVES This study aimed to determine whether distally angulating an implant is a successful strategy to avoid the maxillary sinus and the need for bone augmentation, while increasing the anterior-posterior (A-P) implant distribution in the edentulous maxilla. MATERIALS AND METHODS In 115 patients with edentulous maxillae, virtual implant planning was performed utilizing cone-beam computer tomographs. Axial (8 mm length) and tilted (12 mm length) dental implants with 30-degree and 45-degree angulation were virtually positioned to avoid entering the maxillary sinus, while maximizing A-P distribution. Measurements were made between the tilted and axial implants to assess the change in A-P distribution of implants at the implant and abutment levels. RESULTS Forty-seven sites (20.4%) were not able to have either treatment modality with insufficient bone for implant placement. Axial implants were placed more distally than 45-degree and 30-degree tilted implants in 24% and 42% of sites, respectively. The average change in A-P spread measured at the implant level, for 30- and 45-degree tilted implants was -0.25 mm (95% CI -0.76, 0.26) and 1.9 mm (95% CI 1.4, 2.3), respectively. When measured from the center of each multi-unit abutment the average increase in A-P distances for tilted implants appears larger in the 30-degree and 45-degree groups by 0.97 mm and 1.74 mm, respectively compared to measurements at the implant level. CONCLUSIONS Angulating 12 mm implants provides a limited increase in A-P distribution of implants in edentulous rehabilitation in most situations. In certain patients, the use of 8mm axial implants may provide a greater A-P spread.

A method for creating a complete-arch digital trial tooth arrangement for completely edentulous patients is described. The technique demonstrates an effective way to reproduce the dental and gingival anatomies by using a free 3D modeling software program. This cost-effective, time-saving, and versatile method allows dental professionals to digitally plan challenging treatments for completely edentulous patients. The technique can also be used to fabricate diagnostic prostheses and implant-supported interim prostheses.

Zygomatic implants (ZIs) are used for the oral rehabilitation of patients with maxillectomy defects as an alternative to extensive bone grafting surgeries. New technologies such as computer-assisted navigation systems can improve the accuracy and safety of ZI placement. The intraoral anchorage of fiducial markers necessary for navigation registration is not possible in the case of a severe maxillary defect and lack of residual bone. This technical note presents a novel extraoral registration method for a dynamic navigation system guiding ZI placement in patients with maxillectomy defects. Titanium microscrews were inserted in the mastoid process, supraorbital ridge, and posterior zygomatic arch as registration markers. The mean fiducial registration error (FRE) was 0.53 ± 0.20 and the deviations between the planned and placed ZIs were 1.56 ± 0.54 mm (entry point), 1.87 ± 0.63 mm (exit point), and 2.52 ± 0.84° (angulation). The study results indicate that the placement of fiducial markers at extraoral sites can be used as a registration technique to overcome anatomical limitations in patients after maxillectomy, with a clinically acceptable registration accuracy.

This case report describes a digital workflow for a computer-aided design/computer-assisted manufacturing (CAD/CAM) healing abutment used in immediate implant placement in the esthetic zone. The design of the healing abutment was based on the existing tooth anatomy in order to provide anatomical support to the gingival tissues and to preserve the gingival contours of the natural tooth. This approach enhances the esthetic outcome of the definitive implant restoration. The surgical procedure including the guided bone regeneration is simplified, postoperative morbidity is reduced, and excessive occlusal loading during healing is limited.

Sinus floor elevation with the lateral window approach has proven to be an effective treatment modality for vertical bone augmentation in the posterior region of the maxilla. The simultaneous implant placement during the procedure can be achieved if enough remaining bone height is available to obtain implant primary stability. However, the proper identification of the maxillary sinus boundaries for the window demarcation along with membrane protection for simultaneous implant placement can be challenging. This clinical report demonstrates a novel technique for sinus floor augmentation using a 3D modified implant-osseous-membrane surgical template to assist in the lateral window demarcation, membrane stabilization and protection, and guided implant placement in a partially edentulous patient who was eligible for one-stage sinus floor elevation. The surgical procedure for the sinus demarcation is simplified, the membrane stabilization and protection are effective, and the guided implant placement provided a predictable surgical positioning of the implants.

A procedure is described for fabricating a removable resilient soft-tissue replica that accurately replicates the contoured emergence profile of an interim implant-supported restoration on a cast fabricated by 3D printing. The technique uses digital scanning and 3D printing technologies to produce a 3D printed replica of the implant-supported interim crown, which is then used to fabricate the custom soft-tissue replica. This straightforward technique allows the accurate replication of the emergence profile without retaining the interim crown or fabricating a new one. No additional clinical appointments are needed.

A procedure for registering digital intraoral surface scans onto cone beam computed tomography in the presence of significant scatter artifact is described. The technique uses chairside-fabricated composite resin markers placed on well-distributed teeth to serve as common landmarks in each digital data set for accurate registration. This straightforward, noninvasive, and cost-effective technique facilitates registration without the need for a specialized armamentarium or radio-graphic templates.

Block anesthesia for the maxillary division (V2) of the trigeminal nerve is a suitable approach when an entire quadrant of teeth and/or associated structures are involved. The most effective approach to anesthetize the maxillary branch is intraorally via the greater palatine canal. This case report describes the use of a computer-aided design/computer-assisted manufacturing (CAD/CAM) implant surgical template designed with a guide channel to allow for the administration of maxillary nerve block through the greater palatine canal.