3D-printed shell complete dentures as a diagnostic aid for implant planning and fabricating interim restorations for complete arch rehabilitations: A case series.

3D-printed shell complete dentures generated from a scan of the patient's existing prostheses can simplify and expedite the surgical planning and interim restoration design for complete arch rehabilitations. Three patients were rehabilitated with endosteal implants, and interim restorations were generated from the contours of the 3D-printed shell complete dentures used as diagnostic aids. This case series report presents the recommended protocol and its clinical progression, in addition to clinical and radiographic images of the treatment outcomes.

Trueness of the apical and middle root portion segments of 3D-printed removable die and alveolar cast designs manufactured using stereolithographic 3D printing.

PURPOSE: The present study evaluated the effects of the root portion design, segment (middle vs. apical), and part (die vs. cast) on the trueness of three-dimensional (3D)-printed removable die-cast complex. MATERIAL AND METHODS: The trueness of apical and middle segments of the root portion of 45 3D-printed removable dies and casts with three different root portion designs (n = 15) was assessed using a metrology-grade computer program. The three removable dies and cast designs (root form [RF], conical [CON], and cylindric [CYL]) were created using professional computer-aided manufacturing computer programs (DentalCAD 3.1 Rijeka, and InLab CAD 22.0), and manufactured using stereolithographic 3D printer (Form3; FormLabs, Somerville, MA). Subsequently, the 3D-printed removable dies and casts were scanned by a single operator with an intraoral scanner (PrimeScan; Dentsply Sirona, Charlotte, NC), and their respective standard tessellation language files were aligned and compared to master reference files in a metrology-grade computer program (Geomagic Control X; 3D systems, Rock Hill, NC). The root mean square (RMS) values of the middle and apical segments for each removable die and cast were calculated and analyzed using a mixed model including a repeated measure 3-way analysis of variance (ANOVA) and post-hoc stepdown Bonferroni-corrected pairwise comparisons (α = 0.05). RESULTS: A statistically significant 3-way interaction between factors was detected, suggesting that the part (removable die or alveolar cast) and their design affected the RMS values of their apical and middle root portion segment. (p = 0.045). The post-hoc analysis identified significant differences between RMS values of the apical segments of the CON and CYL removable dies (p = 0.005). Significant differences were observed between the middle and apical segments of the CON (p < 0.001) and RF removable die designs (p = 0.004). No statistically significant differences were noticed between the RMS of the different alveolar cast designs (p > 0.05). Significant differences were detected between the apical and middle segments of the same alveolar cast design (p < 0.05). CONCLUSIONS: For the manufacturing trinomial and 3D printing strategy used in the present study, the interaction of the part, design, and segment affected the trueness of removable dies and alveolar casts. The trueness was higher on the middle segment on removable dies and alveolar casts in all designs used, except for CYL removable dies, where the trueness difference between segments was small. Higher trueness values may be achieved with designs with simple apical segment geometries.

Color stability of precolored and extrinsically colored monolithic multilayered polychromatic zirconia: Effects of surface finishing and aging.

PURPOSE: To explore the impact of zirconia types, coloring methods, and surface finishing on the color stability of monolithic multilayered polychromatic zirconia after artificial aging, including thermocycling and simulated toothbrushing. MATERIALS AND METHODS: Eighty square-shaped zirconia samples were divided into 2 types (M3Y-TZP and M6Y-PSZ), further categorized based on coloring methods (precolored and extrinsically colored) and surface finishing techniques (mechanical polishing or glazing). The color stability was assessed using the CIEDE2000 formula. Artificial aging was simulated via thermocycling and toothbrushing. All samples were analyzed with a spectrophotometer to determine the post-aging color changes (ΔE00). The ΔE00 were interpreted and classified using the 50:50% perceptibility threshold (PT) and the 50:50% acceptability threshold (AT). Comparisons between groups for ΔE00 differences were performed using three-way ANOVA, with pairwise comparisons facilitated by Fisher's protected least significant difference test, α = 0.05. RESULTS: The study results indicated significant impacts of zirconia type, coloring method, and surface finishing on color stability. The M6Y groups experienced significantly greater color changes (6.61 ± 1.63) compared to the M3Y groups (3.40 ± 2.24), p < 0.0001. For both types of zirconia, extrinsically colored samples exhibited significantly higher ΔE00 when mechanically polished (p = 0.004). However, surface finishing had no significant effect on ΔE00 in precolored samples of either zirconia material (p = 1.000). The evaluation and categorization of ΔE00 variations indicated that nearly all color changes in the M6Y groups, regardless of being precolored, extrinsically colored, polished, or glazed, were deemed extremely unacceptable (Grade 1). In contrast, the M3Y groups showed more acceptable results, with the majority of color changes classified as moderately unacceptable (Grade 3). CONCLUSIONS: The color stability of multilayered polychromatic zirconia is influenced by the type of material, extrinsic coloring, and the chosen surface treatment post-artificial aging. The translucent 6Y-PSZ exhibited lower color stability, especially with only mechanical polishing. For the fabrication of M3Y-TZP and 6Y-PSZ monolithic multilayered polychromatic zirconia restorations, extrinsic coloring should be paired with glazing to maintain color stability. Conversely, in the absence of extrinsic coloring, both glazing and mechanical polishing are effective in preserving color stability.

Color stability of CAD-CAM hybrid ceramic materials following immersion in artificial saliva and wine.

PURPOSE: To examine the color stability of 3D-printed and milled, interim, and definitive, restorative materials after immersion in artificial saliva and wine for 1, 3, and 6 months. MATERIAL AND METHODS: The study used a 2 × 5 factorial design with 10 subgroups, including 2 immersion liquids (artificial saliva and wine) and 5 manufacturing technology and restorative material combinations (n = 10). Color measurements were taken using a contact-type digital spectrophotometer (CM-2600d Spectrophotometer; Konica Minolta Healthcare Americas Inc) before immersion and at 1 month (T1), 3 months (T3), and 6 months (T6) after immersion. The CIE2000 system was used to calculate quantitative measurements of color differences in ΔE00, and comparisons were made to the acceptability threshold (AT) and perceptibility threshold (PT). Repeated measures of ANOVA (α = 0.05) were used to compare differences in color changes between manufacturing technology/restorative material-immersion liquid combinations at T1, T3, and T6. RESULTS: To compare the effect of immersion liquid and time on the manufacturing technology/restorative material groups, the ΔE00 values were compared to the PT of 0.8 and the AT of 1.8. Wine caused significant color changes in ΔE00 values beyond the PT and AT values in all groups at all time intervals, except for the AT value of milled definitive crowns (hybrid nano-ceramic material). Wine immersion caused significant ΔE00 for all manufacturing technology/restorative material groups at all time intervals (1 month, 3 months, and 6 months) when compared to artificial saliva immersion (all p < 0.001). CONCLUSION: Upon exposure to artificial saliva, 80%-100% of samples from all groups remained within the acceptable and perceptible color change thresholds. The wine had significant chromogenic effects on all tested restorative materials, however, the milled definitive crowns (hybrid nano-ceramic material) showed the greatest color stability. For patients with heavy wine consumption, 3D-printed definitive crowns (hybrid ceramic-filled material) may show discoloration exceeding acceptable and perceptible color change limits.

The impact of base design and restoration type on the resin consumption, trueness, and dimensional stability of dental casts additively manufactured from liquid crystal display 3D printers.

PURPOSE: To evaluate the effects of two base types and three restoration designs on the resin consumption and trueness of the 3D-printed dental casts. Additionally, the study explored the dimensional stability of these 3D-printed dental casts after 1 year of storage. MATERIALS AND METHODS: Various types of reference dental casts were specifically designed to represent three types of dental restoration fabrications, including full-arch (FA), long-span (LS), and single-unit (SU) prostheses. The reference casts were digitized with a dental laboratory scanner and used to create flat and hollow base designs (N = 18) for the 3D-printed study casts. The 3D-printed study casts were digitized and evaluated against their corresponding references immediately after 3D printing and again after 1 year of storage, with the trueness quantified using the root mean square error (RMSE) at both time points. Volumes of resin used were recorded to measure resin consumption, and the weights of the 3D-printed study casts were also measured. The data were analyzed using two-way ANOVA and a Tukey post hoc test, α = 0.05. RESULTS: Volumetric analysis showed the flat-base design had significantly higher resin consumption with weights for the FA group at 42.51 ± 0.16 g, the LS group at 31.64 ± 0.07 g, and the SU group at 27.67 ± 0.31 g, as opposed to 26.22 ± 1.01 g, 22.86 ± 0.93 g, and 20.10 ± 0.19 g for the hollow designs respectively (p < 0.001). Trueness, assessed through two-way ANOVA, revealed that the flat-base design had lower RMSE values indicating better trueness in the LS (54 ± 6 µm) and SU (59 ± 7 µm) groups compared to the hollow-base design (LS: 73 ± 5, SU: 99 ± 11 µm, both p < 0.001), with no significant difference in the FA group (flat-base: 50 ± 3, hollow: 47 ± 5 µm, p = 0.398). After 1 year, the flat-base design demonstrated superior dimensional stability in the LS (flat base: 56 ± 6 µm, hollow base: 149 ±45 µm, p < 0.001) and SU groups (flat base: 95 ± 8 µm, hollow base: 183 ±27 µm, p < 0.001), with the FA group showing no significant difference in the base design (flat base: 47 ± 9, hollow base: 62 ± 12 µm, p = 0.428). CONCLUSIONS: The hollow-base design group showed lower resin consumption than the flat-base design group. However, the flat-base designs exhibited superior trueness and less distortion after 1 year of storage. These findings indicate that despite the higher material usage, flat-base designs provide better initial accuracy and maintain their dimensional stability over time for most groups.

The 3D-printed shell complete denture technique: Simplifying prosthodontic diagnosis prior to implant planning.

Traditionally, artificial teeth arrangements or the definitive complete dentures are used to establish important prosthodontic parameters such as the occlusal plane orientation, vertical dimension, and the incisal edge position. The relationship of these elements with the underlying bony structures is commonly evaluated using advanced planning protocols such as the dual scan technique. This technique article presents an uncomplicated alternative approach to establish these parameters intraorally using a 3D-printed shell complete denture generated from a 3D scan of the patient's existing complete denture.

Clinical outcomes of milled, 3D-printed, and conventional complete dentures in edentulous patients: A systematic review and meta-analysis.

PURPOSE: This systematic review aims to compare clinical outcomes of digital dentures with conventional dentures. MATERIALS AND METHODS: This study followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and was registered in Prospero. The formulated population, intervention, comparison, outcome (PICO) question was "What is the clinical outcome of digital versus conventional complete dentures (CDs) in edentulous patients?". The search strategy used three main electronic databases and an additional manual search was completed in August 2023 by following an established search strategy. Initial inclusion was based on titles and abstracts, followed by a detailed review of selected studies, and clinical studies that evaluated the clinical outcome of digital (milled or 3D-printed) versus conventional CDs were included. A qualitative analysis for clinical studies was used to assess the risk of bias. The certainty of the evidence was assessed according to the grading of recommendations, assessment, development, and evaluations (GRADE) system. In addition, a single-arm meta-analysis was performed to evaluate the retention between digital versus conventional CDs. RESULTS: The initial search yielded a total of 947 articles, out of which 19 were selected for a comprehensive review, and six met the eligibility criteria to be included in this systematic review. The computer-aided design and computer-aided manufacturing (CAD-CAM) CDs showed increased retention, no relevant differences in oral health-related quality of life (OHRQoL), and shorter working time compared to conventional dentures. Two studies were eligible for meta-analysis; retention was significantly better among CAD-CAM fabricated dentures (standardized mean difference [SMD] 0.501) than conventional dentures. The heterogeneity between studies was high (95% CI: 0.049-0.952). CONCLUSIONS: Clinically, both the milled and the 3D-printed CD fared better than conventional dentures in terms of retention, reduction in the number of appointments, improved patient comfort, and improved predictable maintenance of the denture. Patients' perceptions and satisfaction were independent of the digital and conventional fabricated dentures.

Verifying the seating of a 3D-printed removable die using elastomeric matrices: A dental technique.

Computer-aided design and computer-aided manufacturing systems enable digital designing and 3-dimensional (3D) printing of definitive casts with removable dies. However, the fit of the removable dies should be without interferences for their accurate positioning in the cast. Given that the accuracy of additive manufacturing depends on design- and manufacturing-related factors, verifying the accuracy of the position of 3D-printed removable dies in their cast is essential to fabricate positionally accurate definitive prostheses, which would enable minimal or no laboratory and clinical adjustments. This dental technique article presents a straightforward approach to verify the seating of a 3D-printed removable die by using verification matrices made of a polyvinylsiloxane interocclusal registration material.

Influence of exposure protocol, voxel size, and artifact removal algorithm on the trueness of segmentation utilizing an artificial-intelligence-based system.

PURPOSE: To evaluate the effects of exposure protocol, voxel sizes, and artifact removal algorithms on the trueness of segmentation in various mandible regions using an artificial intelligence (AI)-based system. MATERIALS AND METHODS: Eleven dry human mandibles were scanned using a cone beam computed tomography (CBCT) scanner under differing exposure protocols (standard and ultra-low), voxel sizes (0.15 mm, 0.3 mm, and 0.45 mm), and with or without artifact removal algorithm. The resulting datasets were segmented using an AI-based system, exported as 3D models, and compared to reference files derived from a white-light laboratory scanner. Deviation measurement was performed using a computer-aided design (CAD) program and recorded as root mean square (RMS). The RMS values were used as a representation of the trueness of the AI-segmented 3D models. A 4-way ANOVA was used to assess the impact of voxel size, exposure protocol, artifact removal algorithm, and location on RMS values (α = 0.05). RESULTS: Significant effects were found with voxel size (p < 0.001) and location (p < 0.001), but not with exposure protocol (p = 0.259) or artifact removal algorithm (p = 0.752). Standard exposure groups had significantly lower RMS values than the ultra-low exposure groups in the mandible body with 0.3 mm (p = 0.014) or 0.45 mm (p < 0.001) voxel sizes, the symphysis with a 0.45 mm voxel size (p = 0.011), and the whole mandible with a 0.45 mm voxel size (p = 0.001). Exposure protocol did not affect RMS values at teeth and alveolar bone (p = 0.544), mandible angles (p = 0.380), condyles (p = 0.114), and coronoids (p = 0.806) locations. CONCLUSION: This study informs optimal exposure protocol and voxel size choices in CBCT imaging for true AI-based automatic segmentation with minimal radiation. The artifact removal algorithm did not influence the trueness of AI segmentation. When using an ultra-low exposure protocol to minimize patient radiation exposure in AI segmentations, a voxel size of 0.15 mm is recommended, while a voxel size of 0.45 mm should be avoided.

The Accuracy of Guided Implant Surgery With Different Fields of View of Cone-Beam Computerized Tomography.

Although a smaller size field of view (FOV) of cone-beam computerized tomography (CBCT) reduces radiation exposure, its effect on the accuracy of static computer-aided implant surgery (s-CAIS) remains unknown. This study aimed to evaluate the impact of the size of FOV on the accuracy of s-CAIS and to investigate if the arch affects this effect. A total of 32 implant sites on 8 identical scannable models (maxillae and mandibles) were randomly allocated to 2 FOV sizes: test (5 × 5 cm) and control (10 × 10 cm). All models were scanned with an intraoral scanner (IOS). With the registration of the surface scan and CBCT image, a prosthetic-driven implant position was planned. Following the fabrication of surgical templates, a single-blinded surgeon placed all implants with the fully guided s-CAIS protocol. IOS captured the implant positions with the scan body attached. Implant-planning software measured the angular deviation, 3-dimensional (3D) deviation at the crest, and 3D deviation at the apex between preplanned and actual implant positions. Two-way analysis of variance was used to analyze the effect of FOV and arch on the deviations. The size of FOV did not show a significant effect (P > .198) on angular deviation, 3D deviation at the crest, or 3D deviation at the apex. No significant difference was found when comparing the effect of the size of FOV between the maxillary and mandibular implants. In conclusion, the use of small FOV CBCT demonstrated comparable accuracy of s-CAIS to the use of medium FOV CBCT.

Exploring the impact of the extent of the partially edentulous area on the accuracy of two intraoral scanners.

STATEMENT OF PROBLEM: The accuracy of intraoral scans, particularly in edentulous areas, remains a concern despite the increasing use of digital technology, especially intraoral scanners. PURPOSE: The purpose of this in vitro study was to assess the impact of the extent of an edentulous area on the accuracy (trueness and precision) of intraoral scans from 2 intraoral scanners. MATERIAL AND METHODS: A KaVo dentoform with epoxy resin teeth was used to generate 9 groups with different numbers of teeth removed. A laboratory scanner served as the reference dataset, and 2 intraoral scanners (TRIOS 3 and Primescan AC) were evaluated. A single operator performed all scans following standardized protocols and calibration. Trueness and precision were assessed by using root mean square (RMS) values. Analysis of variance was used to compare trueness and precision values obtained from the 2 scanners and different partially edentulous conditions (α=.05). RESULTS: A significant difference was found in the trueness of intraoral scans of the 2 scanners and under different partially edentulous extensions. Primescan AC exhibited significantly lower trueness than TRIOS 3 (P<.001). For the individual edentulous conditions, Primescan had a significantly higher RMS mean than TRIOS 3 for G0, G3, G4, G6, G7, and G8 (P<.001) and a significantly lower RMS mean than TRIOS 3 for G1 and G4 (P<.001), while no significant difference in RMS mean was found between the 2 scanners for G2 (P=.999). For precision, no significant difference was found between the 2 scanners or different edentulous conditions [(F 8, 90)=1.82, P=.085]. CONCLUSIONS: The accuracy of intraoral scans was influenced by the length of edentulous areas and the scanner used. Primescan AC demonstrated lower trueness than TRIOS 3 for most partially edentulous conditions, while the scanners were similar in precision. These findings highlight the need for careful scanner selection in specific clinical situations, as scanning accuracy may vary depending on the scanner and edentulous condition.

Color reproduction trueness of 3D-printed full-color dental casts with scans derived from an intraoral scanner.

PURPOSE: To investigate the effects of shade tab color variations (tooth-colored vs. gingiva-colored) and surface treatment (application of mineral oil) on the trueness of color reproduction from dental shade tabs to 3D-printed full-color dental casts, using digital scans obtained from an intraoral scanner. MATERIALS AND METHODS: Pristine tooth-colored (with 16 shade tabs) and gingiva-colored (with five shade tabs) shade guides were digitally scanned using an intraoral scanner, and subsequently, 3D-printed replicas were created using a full-color material jetting 3D printer. Three color measurements using a contact type digital spectrophotometer were recorded, including actual shade tabs (R0), dried 3D-printed study samples (RP1 ), and study samples with mineral oil application (RP2 ), in this study to calculate color differences between the actual shade tabs and 3D-printed ones. The CIEDE2000 formula was used to calculate the color differences (color reproduction trueness) between reference shade tabs and 3D-printed full-color study samples-without and with mineral oil, ∆E00 (RP1 ), and ∆E00 (RP2 ). ∆E00 (RP1 ) and ∆E00 (RP2 ) were compared with a 50:50% accessibility threshold (AT) and a 50:50% perceptibility threshold (PT). A grading system, based on the relative ranges of AT and PT, was employed. The percentage of samples falling into each color-matching category was then recorded. The data collected were subjected to statistical analysis, utilizing a mixed model ANOVA to evaluate the effects of shade tab color and mineral oil application on color differences, α = 0.05. RESULTS: The application of mineral oil significantly affected the ∆E00 [F(1, 378) = 19.1, p = < 0.0001]. However, this effect was only significant for the gingiva-colored study samples; the mineral oil application significantly decreased color difference, showing ∆E00 (RP1 ) of 8.71 ± 3.78 and ∆E00 (RP2 ) of 6.55 ± 2.14 (p < 0.0001). For the tooth-colored groups, the mineral oil application did not yield any color difference, showing ∆E00 (RP1 ) of 7.05 ± 2.35 and ∆E00 (RP2 ) of 6.94 ± 2.35 (p = 0.497). In the absence of mineral oil, gingiva-colored samples revealed a significantly larger ∆E00 (RP1 ) of 8.71 ± 3.78 compared to tooth-colored samples at 7.05 ± 2.35 (p = 0.017). Conversely, mineral oil application rendered comparable ∆E00 (RP2 ) values between gingiva-colored (6.55 ± 2.14) and tooth-colored (6.94 ± 2.35) samples (p = 0.558). All 3D-printed full-color samples showed Grade 1 (extremely unacceptable mismatch) and Grade 2 (clearly unacceptable mismatch), regardless of the shades or the presence of mineral oil. CONCLUSIONS: Utilizing an intraoral scanner to gather digital color data, along with an MJ 3D printer, offers the potential for producing 3D-printed full-color dental casts for prosthesis characterization in the dental laboratory. While mineral oil improves the color reproduction trueness of gingiva-colored objects, all 3D-printed full-color samples exhibited unacceptable mismatches when compared to their target objects. This underscores the need for future improvement in the digital color data acquisition process and color optimization protocols in 3D printing processes.

Comparison of surface characteristics of denture base resin materials with two surface treatment protocols and simulated brushing.

PURPOSE: To investigate the effects of 4 denture base materials, 2 surface treatment protocols, and simulated brushing (SB) on the surface hardness, surface roughness, surface gloss, and the surface loss of denture base materials. MATERIALS AND METHODS: Four denture base resin material groups (compression-molded, injection-molded, 3D-printed, and milled) with two different surface treatment protocols (polished and glazed) were utilized in this study. A total of 80 samples (n = 10) were evaluated for surface hardness (Vickers) before SB. SB was performed for each sample (custom-built V8 cross brushing machine, 50,000 reciprocal strokes). Surface roughness (Ra) was measured before and after SB with a non-contact optical profilometer. Surface gloss was performed using a glossmeter to determine changes in surface reflectivity of the specimens before and after SB. Surface loss (wear resistance) was measured after SB using optical profilometry. The effects of material, surface treatment, and SB on all surface characteristics were examined with two-way and three-way analysis of variance models (ANOVA) (α = 0.05). RESULTS: The polished compression-molded group had significantly higher surface hardness than all other groups. The protective glaze coating significantly increased the surface hardness for all groups (P < 0.001). SB increased the surface roughness of all groups regardless of surface treatments (P < 0.001). The increase in surface roughness after SB was significantly higher with polished surface treatment than with a glazed surface treatment in all groups (P < 0.001). Surface gloss was significantly higher with the glazed surface treatment than with the polished surface treatment for all denture base materials (P < 0.001). After SB, milled denture base material showed the highest, and 3D-printed material showed the second highest surface gloss compared to the other groups (P < 0.001), regardless of surface treatment. In all materials tested, surface glaze significantly decreased surface loss (P < 0.001). With the glaze surface treatment, compression-molded denture base material had significantly less surface loss (more surface gain) than other materials, while with the polished surface treatment, 3D-printed denture base material had the least surface loss when compared with other groups. CONCLUSIONS: A single layer of nano-filled, light-polymerizing protective glaze coating has displayed potential for enhancing the longevity of denture base materials, as evidenced by increased hardness and wear resistance. Following simulated brushing, the milled denture material exhibited the highest surface gloss and lowest surface roughness among all groups, regardless of the surface treatment protocol. This indicates that milled denture base material possesses favorable surface properties and may serve as a viable alternative to traditional denture base materials.

Accuracy of digital duplication scanning methods for complete dentures.

PURPOSE: To compare the accuracy of four digital scanning methods in duplicating a complete denture. MATERIAL AND METHODS: Four scanning methods were used: cone beam computed tomography (CBCT), Straumann desktop scanner (DS), Trios intraoral scanner (TIO), and Virtuo Vivo intraoral scanner (VVIO). Each method was used to duplicate all the surfaces of a printed complete denture. The denture was scanned 10 times in each group. The trueness (in root mean square, RMS) and precision (in standard deviation, SD) were calculated by comparing the combined dentition, denture extension, and intaglio surfaces with the reference file. One-way analysis of variance and F-tests were used to test statistical differences (α = 0.05). RESULTS: For the scanning accuracy of the whole denture, CBCT showed the highest RMS (0.249 ± 0.020 mm) and lowest trueness than DS (0.124 ± 0.014 mm p < 0.001), TIO (0.131 ± 0.006 mm p < 0.001), and VVIO (0.227 ± 0.020 mm p = 0.017), while DS and TIO showed smaller RMS than VVIO (p < 0.001). For the trueness of dentition, denture extension, and intaglio surfaces, CBCT also showed the highest mean RMS and lowest trueness among all groups (p < 0.001). DS and TIO had smaller mean RMS and higher trueness among all groups in all surfaces (p < 0.001, except VVIO in intaglio surface, p > 0.05). TIO had significantly lower within-group variability of RMS and highest precision compared to DS (p = 0.013), CBCT (p = 0.001), and VVIO (p < 0.001) in the combined surface. For dentition and denture extension surfaces, TIO showed similar within-group variability of RMS with the DS group (p > 0.05) and lower than CBCT and VVIO (p < 0.001). CONCLUSION: The 7 Series desktop scanner and Trios 4 intraoral scanner can duplicate dentures in higher trueness than CBCT and the Virtuo Vivo intraoral scanner. The Trios 4 intraoral scanner was more precise in the combined surfaces than other scanning methods, while the 7 Series desktop scanner and Trios 4 intraoral scanner were more precise in the denture extension surface.

ITI consensus report on zygomatic implants: indications, evaluation of surgical techniques and long-term treatment outcomes.

OBJECTIVES: The aim of the ITI Consensus Workshop on zygomatic implants was to provide Consensus Statements and Clinical Recommendations for the use of zygomatic implants. MATERIALS AND METHODS: Three systematic reviews and one narrative review were written to address focused questions on (1) the indications for the use of zygomatic implants; (2) the survival rates and complications associated with surgery in zygomatic implant placement; (3) long-term survival rates of zygomatic implants and (4) the biomechanical principles involved when zygoma implants are placed under functional loads. Based on the reviews, three working groups then developed Consensus Statements and Clinical Recommendations. These were discussed in a plenary and finalized in Delphi rounds. RESULTS: A total of 21 Consensus Statements were developed from the systematic reviews. Additionally, the group developed 17 Clinical Recommendations based on the Consensus Statements and the combined expertise of the participants. CONCLUSIONS: Zygomatic implants are mainly indicated in cases with maxillary bone atrophy or deficiency. Long-term mean zygomatic implant survival was 96.2% [95% CI 93.8; 97.7] over a mean follow-up of 75.4 months (6.3 years) with a follow-up range of 36-141.6 months (3-11.8 years). Immediate loading showed a statistically significant increase in survival over delayed loading. Sinusitis presented with a total prevalence of 14.2% [95% CI 8.8; 22.0] over a mean 65.4 months follow-up, representing the most common complication which may lead to zygomatic implant loss. The international experts suggested clinical recommendations regarding planning, surgery, restoration, outcomes, and the patient's perspective.

Performance of the caries diagnosis feature of intraoral scanners and near-infrared imaging technology-A narrative review.

PURPOSE: To describe and discuss the benefits and drawbacks of various dental caries diagnostic techniques, including the use of intraoral scanners for caries diagnosis based on near-infrared imaging (NIR) technology. MATERIAL AND METHODS: A MEDLINE search from 1980-2023 focused on dental caries diagnostic techniques, emphasizing intraoral scanners using NIR technology. Alternative caries detection methods were also evaluated for their advantages and limitations, enabling a comparison with NIR. The review included traditional caries tools, the latest detection methods, and NIR's role in intraoral scanners, drawing from case reports and both in vivo and in vitro studies. Keywords like "caries detection," "intraoral scanners," and "Near Infrared Imaging (NIRI)" guided the search. After screening titles and abstracts for relevance, full texts with valuable insights were thoroughly analyzed. The data was grouped into three: traditional diagnostics, advanced digital methods, and intraoral scanner-based detection. RESULTS: This comprehensive narrative review described and discussed the current state of dental caries diagnostic methods, given the insufficient number of clinical investigations suitable for a systematic review. Traditional caries diagnosis techniques have shown variable accuracy dependent on a dentist's experience and the potential over-removal of healthy tooth structures. Intraoral scanners have emerged as a novel caries detection method, because of their integration of NIR technology. Various studies have confirmed the efficacy of NIR in detecting interproximal caries and in the early diagnosis of non-cavitated caries. Specifically, intraoral scanners have demonstrated promising results, proving comparable to established diagnostic methods like bitewing radiography. Nevertheless, while the integration of NIR into intraoral scanners seems promising, the technology still faces challenges, notably its accuracy in detecting secondary and subgingival cavities. However, with anticipated integrations of AI, NIR in intraoral scanners could revolutionize early caries detection. CONCLUSIONS: Intraoral scanners with NIR technology offer non-destructive imaging, real-time lesion visuals, and enhanced patient communication. Although comparable to bitewing radiography in some studies, a universally accepted diagnostic tool is lacking. Future research should compare them with existing methods, focusing on clinical outcomes, cost-effectiveness, and patient acceptance.

Indications for zygomatic implants: a systematic review.

PURPOSE: The purpose of this systematic review was to assess the evidence regarding the indications for placement of zygomatic implants to rehabilitate edentulous maxillae. MATERIAL AND METHODS: A focused question using the PIO format was developed, questioning "in patients in need of an implant-supported rehabilitation of the edentulous maxillae, what are the indications for the use of zygomatic implants''. The primary information analyzed and collected was a clear description of the indication for the use of zygomatic implants. RESULTS: A total of 1266 records were identified through database searching. The full-text review was conducted for 117 papers, and 10 were selected to be included in this review. Zygomatic implant indications were extreme bone atrophy or deficiency secondary to different factors. The quad zygoma concept (two zygomatic implants bilaterally placed and splinted) was applied to 107 patients, the classic zygoma concept (one zygomatic implant bilaterally placed and splinted to standard anterior implants) was used in 88 patients, and the unilateral concept (one zygomatic implant on one side, splinted with one or more conventional implants) was employed in 14 patients. CONCLUSIONS: The main indication for the use of zygomatic implants was considered extreme maxillary bone atrophy, resulting from many factors. The clear definition of what was considered "extreme bone atrophy" is not uniquely defined in each paper. Further studies are needed to develop clear indications for zygomatic implants.

Complications related to digital technologies in treating edentulous patients with dental implants-Part II. Computer-guided surgery and prosthetic stages.

This is the second part of a JPD Digital presentation focusing on commonly seen complications and solutions related to using digital technologies in treating edentulous patients during the surgical and prosthetic stages. The proper usage of the computer-aided design and computer-aided manufacturing surgical templates and immediate loading prosthesis during computer-guided surgery and accurate translation of digital planning into clinical execution are discussed. In addition, design concepts of implant-supported complete fixed dental prostheses are presented to minimize subsequent issues in their long-term clinical service. In concert with these topics, this presentation will allow clinicians to deepen their understanding of the advantages and limitations of utilizing digital technologies in implant dentistry.