Journal of Prosthodontics-Implant Esthetic and Reconstructive Dentistry最新文献

Purpose: The bone-implant interface plays a crucial role in obtaining sufficient primary stability for dental implants in weak bone supports. The aim of this human cadaver study was to evaluate the primary stability of new thin-threaded implants when placed in type IV bone right after maxillary sinus floor elevation.

Materials and methods: The study followed the CACTUS (ChAracteristics of Cadaver Training and sUrgical Studies) guidelines. Twenty-four edentulous maxillary posterior zones with type IV bone and a residual bone height of 4 mm were selected using computed tomography scans. First, an osteotome sinus floor elevation was performed (C.M.C Tech, IBS IMPLANT, Daejeon, South Korea). Implants with thin threads (MagiCore, IBS IMPLANT, Daejeon, South Korea) were placed simultaneously. Samples were divided into two groups: Group 1 (G1): 11 mm-long implants with an elevation of 8 mm; Group 2 (G2): 7 mm-long implants with an elevation of 4 mm. Primary stability was assessed using resonance frequency analysis (RFA).

Results: The average primary stability values in the mesiodistal (MD) direction were 45.67 ± 3.09 Implant Stability Quotient (ISQ) for G1 and 38.76 ± 16.94 ISQ for G2, and in the buccolingual direction were 43.33 ± 13.23 ISQ for G1 and 38.47 ± 16.14 ISQ for G2.

Conclusions: The primary stability of the thin-threaded implants was compatible with clinical osseointegration in sinus sites with limited bone contact area in both experimental situations. Clinical studies are needed to confirm these encouraging results.

Purpose: Sleep apnea is a common and underdiagnosed sleep-related breathing disorder. This systematic review aimed to evaluate the scientific evidence regarding the association between obstructive sleep apnea (OSA) and edentulism.

Methods: An electronic search was conducted through PubMed (MEDLINE), Scopus, and Cochrane Library, up to January 2024. A systematic approach was followed according to the PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) statement guidelines. The literature search intended to retrieve all relevant clinical studies about any possible association between OSA and edentulism. Only publications in the English language were selected, and animal studies, in vitro studies, case reports, case series, technique presentation articles, and expert opinions were excluded.

Results: A total of 23 studies met the inclusion criteria and were included in this systematic review. They were published between 1999 and 2023 and were all clinical studies. These studies examined a possible association between OSA and edentulism and all of them agreed on their positive relation. Tooth loss favors anatomic alterations that deteriorate breathing. The severity of OSA was related to the extent and duration of edentulism. Mean Apnea-Hypopnea Index (AHI) scores in edentulous patients were found to be two to three times higher in comparison to dentate individuals, although the statistical data about it are scarce. No agreement was reached, however, about the use of dentures during sleep time, since the data are controversial.

Conclusion: The findings suggest that there is a plausible association between edentulism and OSA. Tooth loss impairs significant anatomic alterations and increases the risk for OSA. However, clinical data are limited and heterogeneous so more clinical studies should be encouraged for more robust conclusions.

Purpose: To quantify facial esthetic outcomes of prosthetic upper lip support in both full animation and repose for patients with an existing implant-supported fixed complete dental prosthesis (ISFCDP).

Materials and methods: Twenty patients had a removable prosthetic labial flange fabricated for their existing maxillary prosthesis. The 3dMDface system was used to capture video sets of each patient going from repose to high smile with and without the labial flange. A single frame representing high smile and repose was selected from each video. Five facial anatomic markers and 21 individual points on the upper lip were evaluated for both image sets using quantitative photometric analysis. To provide a qualitative assessment, the same images were shown to dentists, laypeople, and the research subjects (patients) to determine which they found to be more esthetically pleasing, or if there was no difference. Quantitative data was evaluated using paired t-tests.

Results: The two-dimensional analysis showed a difference with and without a labial flange for lip projection and lip thickness. Additionally, 13 out of 21 landmarks in the three-dimensional analysis showed differences when comparing the superimposed labial flange and no flange linear difference values between high smile and repose. Survey results showed that research subjects (54.41%), dentists (51.50%), and laypeople (44.50%), all preferred labial flange versus no flange photos or were not able to tell a difference.

Conclusions: Qualitative and quantitative results suggest that a prosthetic labial flange has an impact on upper lip support. Clinicians should consider lip support both in full animation and repose when treatment planning for the maxillary ISFCDP.

Purpose: To determine the influence of using 3D-printed scan aids in varying colors on the trueness of digital scans.

Materials and methods: A master cast with five multi-unit analogues was scanned. The acquired dataset was exported to standard tessellation language (STL) file format to serve as the reference STL. 3D printing of the prototype in five distinct colors (beige [SA^BEIGE], grey [SA^GREY], white [SA^WHITE], red [SA^RED], and blue [SA^BLUE]) of polylactic acid filament was executed. The experimental STLs of each color group were aligned to the reference STL. RMS values were solely computed for the scan bodies. Based on the centers of the created best-fit and offset planes, scan bodies were converted into virtual cylinders. Cartesian coordinates of each cylinder were acquired. Subsequently, angular (AD) and linear deviation (LD) values were calculated. LD was further examined separately along the x, y, and z axes. Data were statistically analyzed.

Results: According to the results of one-way ANOVAs, significant differences were detected among color groups on AD, LD, RMS estimate error, ∆x, ∆y, and ∆z data. The lowest AD and LD values were exhibited by the SA^GREY group in all implant sites. The SA^GREY group was followed by the SA^BEIGE, SA^WHITE, SA^RED, and SA^BLUE groups.

Conclusions: The SA^GREY outperformed the other groups in terms of trueness. Although the LD values of all color groups were below the threshold value (<100 µm), only the AD values of the SA^GREY, SA^BEIGE, and SA^WHITE groups were clinically acceptable (<0.5°).

This clinical report outlines the prosthetic restoration of a 92-year-old Caucasian patient who underwent a partial rhinectomy. Utilizing CAD-CAM technology, scanning and design were accomplished digitally, and material jetting additive manufacturing was used to create a two-piece mold for a partial nasal silicone prosthesis. An unprecedented challenge was observed involving cure inhibition when the silicone came into contact with the additively manufactured (AM) material, and multiple attempted strategies to remedy this situation were discussed. The report emphasizes the critical need for further research to optimize digital workflows in prosthetic facial rehabilitation.

Purpose: This study investigated the effect of three digital bite registration techniques on the accuracy of intraoral scanning in maxillary edentulous and mandibular dentate arches.

Materials and methods: Maxillary edentulous and mandible fully dentate models were created. Four dental implants were placed in the maxilla, fitted with scan bodies, and reference scans were obtained using a Nikon Altera 10.7.6 scanner. Digital impressions were acquired 10 times for each model using a Trios 4 intraoral scanner. Three different digital bite records were collected for each pair of mandible and maxilla scans. The first one was a bite record without additional material (WSB), the second utilized a silicone index between the models (WSB silicone), and the third followed a pre-preparation scanning protocol (Pre-PREP). The data was exported in standard tessellation language (STL) format, which was assessed for trueness and precision using statistical analysis.

Results: According to mean trueness values, WSB exhibited the lowest value, 173 µm, followed by WSB silicone 242 µm and Pre-PREP 620 µm. The differences were significant only when comparing Pre-PREP to WSB and Pre-PREP to WSB silicone (p < 0.05). Regarding precision, WSB demonstrated a mean value of 171.5 µm, followed by WSB silicone with 213.8 µm, and Pre-PREP with 222.2 µm with no significant difference between the groups.

Conclusion: The presence of interarch bite registration material adversely affected interocclusal record accuracy, while WSB silicone presented a suitable substitute for WSB.

Pterygoid implant placement has been proven to be a viable option in full-arch implant rehabilitation for extremely atrophic maxillae. Nevertheless, the utilization of pterygoid implants remains a challenge for the dentist due to the difficulties of accessing the surgical site and poor visibility. To address these difficulties, digital techniques have been used to enhance the accuracy of pterygoid implant placement. This clinical case describes the application of an autonomous robot system to enhance the precision and efficacy of pterygoid implant placement. The results demonstrated that the integration of automation and real-time imaging provided by the robot system significantly improved the safety and accuracy of the surgical procedure.

This clinical report introduces a digital approach that utilizes milled verification jigs to acquire the jaw relations for the fabrication of monolithic zirconia implant-supported fixed complete dental prosthesis (IFCDP), in patients without a conversion implant prosthesis. The procedures employ photogrammetry for precise data acquisition, combined with image-based capture in 4 dimensions (ICAM4D), to design and mill verification jigs that accurately record the occlusal vertical dimension (OVD) and centric relation (CR). This approach streamlines the clinical workflow by reducing the number of patient visits and associated costs while enhancing precision and predictability. It eliminates the need for conventional steps and analog definitive casts in the fabrication of IFCDP without a conversion implant prosthesis.

Purpose: This study aimed to assess the influence of magnetic resonance imaging (MRI) protocol on the decision-making for the positioning of dental implants in edentulous arches in comparison to planning based on cone beam computed tomography (CBCT).

Materials and methods: One phantom was scanned with CBCT and two MRI protocols (T1- and T2-weighted). Two calibrated examiners performed digital implant planning (coDiagnostiX, Dental Wings), considering a digital prosthetic planning and alveolar ridge surface scan. Four implants were planned for each patient dataset, and the angular deviation between the long axis of the implants and the prosthetic planning occlusal plane was measured.

Results: Each examiner planned 40 implants, 12 implants with CBCT and 28 implants with MRI (16 with T1 and 12 with T2 images). Significant differences in angle deviation were observed between CBCT, T1, and T2 in the anterior region for both examiners (p = 0.009 for examiner 1 and p = 0.042 for examiner 2). Implants planned with CBCT showed significantly lower angular deviation than those based on the T1 and T2 scans for both examiners (p = 0.028 and p = 0.046 for examiner 1 and p = 0.028 and p = 0.027 for examiner 2). No significant difference in angular deviation was found between T1 and T2 for both examiners (examiner 1: p = 0.600, examiner 2: p = 0.916).

Conclusion: Compared to CBCT planning, the MRI protocol influenced decision-making for anterior dental implants, with angular deviations within acceptable clinical thresholds, but further studies are needed to validate these findings.

Purpose: This study aimed to evaluate the cytotoxicity of a biocompatible 3D-printed resin material for occlusal devices after post-processing with two different high-intensity UV-polymerization devices and two rinsing solvents, in the presence of human gingival fibroblasts (HGFs).

Material and methods: Sample discs from the 3D-printed resin material were printed (2 mm in height and 6 mm in diameter [N = 40]) and divided into 4 groups (n = 10) based on post-processing methods: a high-intensity UV polymerization device with isopropyl alcohol, a high-intensity UV polymerization device with a modified glycol solvent, a UV cleaning and curing unit with isopropyl alcohol, a UV cleaning and curing unit with a modified glycol solvent, and a control group cultured in DMEM medium. Different tests were performed to evaluate their cytocompatibility on HGFs: MTT assay, cell migration assay, cell cytoskeleton staining, scanning electron microscopy (SEM), and cell apoptosis and generation of intracellular reactive oxygen species (ROS). Statistical analyses were performed using one-way ANOVA and the Tukey post hoc test (α = 0.05).

Results: Cytocompatibility, MTT assay, cell migration assay, cell cytoskeleton staining, and SEM images were similar, regardless of the post-processing protocol, compared with the control group.

Conclusions: No differences were found in the cytotoxicity of the 3D-printed resin material for occlusal devices after the following post-processing methods: two different UV-polymerization devices and two rinsing solvents (isopropyl alcohol and a modified glycol solvent).