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

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).

Although there are difficulties with using intraoral scans for implant-supported complete-arch fixed dental prostheses (ISCFDPs), several commercially available systems have become helpful in simplifying the treatment process in the prosthetic phase. These systems help patients move from interim ISCFDPs to receiving definitive prostheses in just three clinical visits. This clinical report summarizes the indications, benefits, and limitations of the four systems. The information provided in this report about the digital prosthetic workflow of ISCFDPs aims to help clinicians make well-informed choices and improve treatment results. With digital technologies advancing, refining these tools and protocols, and validating research is crucial for continued evolution in the field.

Sleep-related bruxism (SRB) is a motor oral behavior characterized by tooth grinding and jaw clenching activity, reported by 8%-12% of the adult general population and 3% of older individuals. The frequency of one of its biomarkers, rhythmic masticatory muscle activity (RMMA), remains elevated across ages. Obstructive sleep apnea (OSA) is associated with the brief and repetitive pause of breathing (apnea) and with transient reduction in oxygen (hypoxia). OSA is observed at all ages and in about 50% of older individuals with a male preponderance. SRB clinical assessment is based on self-reporting of tooth grinding sound, awareness of clenching, jaw pain or headache, and clinical observation of tooth damage. OSA clinical assessment is based on sleepiness and fatigue, snoring, sleep quality, and awareness of breathing cessation, plus clinical examination of anatomical factors (e.g., obesity, retrognathia, large tonsil, macroglossia), age, gender, and body mass. Although the literature does not support association or causality between these two conditions, the co-occurrence is reported in about 30%-50% of adults. To confirm a diagnosis of co-occurring SRB and OSA, home sleep testing (HST) may be indicated. A sleep test is performed using electromyography (EMG) of jaw muscle (masseter or temporalis) and cardio-respiratory variables (e.g., air flow, respiratory effort, oxygen level, heart rate). The management of co-occurring SRB and OSA for individuals with prosthodontic needs is challenging to prevent compromising the oro-pharyngeal space and breathing efficiency. OSA treatment in the presence of SRB includes continuous positive airway pressure (CPAP) use alone or with an occlusal splint or mandibular advancement device (MAD). In addition, the following may be considered: supine sleep correction device, myofuncional therapy, medications, and surgeries. All have limitations and risks. Individual variability suggests that phenotyping is mandatory to select the most efficient and personalized treatment.

Purpose: This in vitro study aimed to compare the 3-dimensional (3D) accuracy of intraoral and desktop scanners when digitizing the post and core polyvinyl siloxane impressions.

Material and methods: Ten extracted human teeth were prepared to build a post space in the root canal. Each tooth was scanned using a micro-computed tomography device (MCT), and the slice data were reconstructed as controls. A conventional quadrant polyvinyl siloxane impression was made and scanned thrice using an intraoral scanner (IOS) and a desktop blue-light scanner (IMS), with one of the scans randomly selected as the definitive cast. Precision was assessed by comparing the deviations among repeated scans. Trueness was evaluated by analyzing the deviations between the MCT and each definitive cast (MCT-IOS and MCT-IMS). The clinically acceptable root mean square (RMS) value was set to 50 µm.

Results: The mean RMS values of the repeated scans of IOS and IMS were 18.3 ± 3.9 µm and 13.9 ± 6.2 µm (P < 0.05), and the difference between them was 4.4 ± 5.9 µm. The mean RMS values of MCT-IOS and MCT-IMS were 28.3 ±3.0 µm and 31.3 ± 4.2 µm (P < 0.05), with a difference of 3.0 ± 2.9 µm. The RMS values were significantly lower than 50 µm (P < 0.05).

Conclusions: The IOS showed slightly better trueness than the IMS but slightly lower precision. The precision and trueness of the two scanners for digitizing post and core impressions were acceptable for clinical application.

Purpose: To evaluate the changes in abutment screw removal torque value (RTV) of anatomic, original hybrid, and non-original hybrid abutments after simulated clinical use.

Materials and methods: Ninety-three implant-abutment-crown specimens were divided into groups according to abutment types (n = 31): anatomic (stock) (A), original hybrid (OH), and non-original hybrid (NOH). After the initial abutment screw tightening, the specimens were subjected to five screw tightening (insertion/removal) cycles, or to 5000 thermal cycles with 500,000 chewing cycles combined with one or five screw tightening cycles. RTV measurements and surface analysis using scanning electron microscope were performed before and after aging. The impact of abutment types and aging treatments on RTV was determined using two-way repeated measures ANOVA, data were described with mean ± SD and range, whereas the differences were significant at p < 0.05.

Results: A significant interaction was found between abutment types and screw tightening cycles only (p = 0.036) or combined with thermomechanical aging (p < 0.001) on RTV. RTV was lower in NOH than in A and OH groups after screw tightening and thermomechanical aging (p < 0.05). Before aging, the NOH abutment screw was slightly more damaged than OH and A abutment screws. After aging, screw damage was more pronounced on the surfaces of hybrid abutments, and more evident in the NOH group.

Conclusions: The abutment screw RTV of anatomic, original hybrid, and non-original hybrid abutments become significantly lower after abutments undergo screw tightening and/or thermomechanical aging cycles, with higher RTV loss in hybrid abutments, especially non-original ones.

Purpose: To compare trueness, time, and number of images of different denture digitization protocols.

Materials and methods: Maxillary and mandibular complete prostheses (n = 10) were fabricated and attached with four fiducial markers. Reference scans were obtained using a laboratory scanner. Test scans were obtained using three different protocols: intraoral scanner (IOS) with manufacturer's scanning pattern (MA), IOS with rolling scanning pattern (RO), and IOS- polyvinylsiloxane technique (IOS-PVS). The scan time and number of images taken were recorded for analysis. Using 3-dimensional (3D) inspection software (Geomagic control X), corresponding test scans were superimposed to the reference scan using overall best fit. For trueness analysis, the root mean square (RMS) value of the overall best-fit superimposition was calculated. One-way ANOVA followed by Games-Howell and Tukey post-hoc tests were applied to analyze trueness, scan time, and number of images. Qualitative analysis of trueness was performed using 3D color mapping.

Results: The lowest RMS value was in the mandibular RO protocol (0.10 ±0.01 mm). The highest RMS value was mandibular scans of the IOS-PVS protocol (1.46 ± 0.09 mm). The longest digitization time was recorded in the maxillary MA group (3.34 ± 0.70 min), while the shortest was in the mandibular RO protocol (2.48 ± 0.56 min). Qualitative analysis revealed that deviation in IOS-PVS protocol occurred around the border area of the prosthesis.

Conclusion: The denture digitization protocols tested significantly affected trueness, total scanning time, and number of images. Digitizing dentures using the RO protocol improved trueness and reduced scanning time and the number of images.

Purpose: To evaluate how build orientation affects the fabrication trueness of additively manufactured implant-supported complete arch prostheses by comparing them to subtractively manufactured high-impact polymer-based prostheses.

Materials and methods: An edentulous maxillary model with four implants at canine and first molar regions bilaterally was digitized (ATOS Core 80 5MP) to design a reference implant-supported complete arch prosthesis standard tessellation language file (RF-STL). The STL file was used to manufacture prostheses additively in five different orientations according to the build platform (AM-0, 0-degree; AM-15, 15-degree; AM-30, 30-degree; AM-45, 45-degree; AM-90, 90-degree) or subtractively (SM-HIP, control) (n = 10). The prostheses were digitized with an intraoral scanner (Trios 3) to generate their STLs (TF-STL). After superimposing TF-STLs over the RF-STL with a metrology-grade analysis software program (Geomagic Control X), surface deviations at four regions (overall, occlusal, overall without occlusal, and abutments), linear deviations at each abutment site, and interimplant distance deviations (canine-to-molar, canine-to-canine, and molar-to-molar) were calculated. One-way analysis of variance and Tukey HSD tests were used for the statistical analyses (α = 0.05).

Results: AM-90 mostly had the highest surface deviations, while AM-0 had the lowest overall, and lowest overall without occlusal region deviations (p ≤ 0.022). SM-HIP had the lowest occlusal region deviations (p < 0.001). AM-90 had the highest linear deviations (p < 0.001). AM-15 had higher canine-to-molar deviations than SM-HIP (p = 0.042). SM-HIP had the highest canine-to-canine deviations, while AM-90 had higher deviations than AM-0 and AM-30 (p ≤ 0.026). AM-45 and AM-90 had the highest and AM-0 had the lowest molar-to-molar deviations (p ≤ 0.013).

Conclusions: AM-0 mostly had higher trueness and AM-90 mostly had lower trueness within tested outcomes. Additively manufactured prostheses mostly had lower canine-to-molar distances and higher molar-to-molar distances, whereas SM-HIP prostheses consistently had higher distances than the design file.