Journal of Advanced Prosthodontics最新文献

Purpose: This study assesses the impact of additional reference objects (RO) on the trueness and precision of distance and angle measurements between scan bodies in digital scans with four different intraoral scanners (IOS) in partially edentulous models.

Materials and methods: Maxilla models (Frasaco, Frasaco GmbH, Tettnang, Germany) with one (3-U) and two (4-U) missing posterior teeth were 3D printed and fitted with dental implants and scan bodies. Four intraoral scanners (Primescan (Dentsply Sirona, Charlotte, NC, USA) (PS), Trios 3 (3Shape) (T3), Trios 4 (3Shape) (T4), and CS3600 (Carestream Dentistry) (CS)) captured digital implant impressions with and without additional RO. Scans were aligned and assessed for distance and angulation measurements between scan bodies. Statistical analyses compared trueness and precision across model groups using the Student t-test and Welch's ANOVA.

Results: CS consistently showed the highest distance values across IOS devices in both the 4-U and 3-U models (P < .05), both with and without RO. The distance values were not considerably affected by the presence of RO (P > .05), except for a few isolated cases in the PS and CS groups of 3-U models. When measuring angles, CS usually showed greater values than the other IOS devices, especially when RO was present both in the 4-U and 3-U variants (P < .05).

Conclusion: The influence of additional reference objects on accuracy varies with different scanner types, irrespective of edentulous area length.

Purpose: This study aimed to evaluate the reliability and validity of a four-item questionnaire using a face rating scale to measure dental trait anxiety (DTA), dental trait fear (DTF), dental state anxiety (DSA), and dental state fear (DSF).

Materials and methods: Participants were consecutively selected from patients undergoing scaling (S-group; n = 47) and implant placement (I-group; n = 25). The S-group completed the questionnaire both before initial and second scaling, whereas the I-group responded on the pre-surgery day (Pre-day), the day of implant placement (Imp-day), and the day of suture removal (Post-day).

Results: The reliability in the S-group was evaluated using the test-retest method, showing a weighted kappa value of DTA, 0.61; DTF, 0.46; DSA, 0.67; DSF, 0.52. Criterion-related validity, assessed using the State-Trait Anxiety Inventory's trait anxiety and state anxiety, revealed positive correlations between trait anxiety and DTA/DTF (DTA, ρ = 0.30; DTF, ρ = 0.27, ρ: correlation coefficient) and between state anxiety and all four items (DTA, ρ = 0.41; DTF, ρ = 0.32; DSA, ρ = 0.25; DSF, ρ = 0.25). Known-group validity was assessed using the initial data and Imp-day data from the S-group and I-group, respectively, revealing significantly higher DSA and DSF scores in the I-group than in the S-group. Responsiveness was gauged using I-group data, showing significantly lower DSA and DSF scores on post-day compared to other days.

Conclusion: The newly developed questionnaire has acceptable reliability and validity for clinical use, suggesting its usefulness for research on dental anxiety and fear and for providing patient-specific dental care.

Purpose: This study aimed to evaluate the clinical performance of implant-assisted removable partial dentures (IARPD) with surveyed crowns, also known as implant-crown-retained removable partial dentures (ICRPDs).

Materials and methods: Electronic searches of MEDLINE/PubMed, the Cochrane Central Register of Controlled Trials, the Web of Science, and the Korea Citation Index were performed according to the established search terms for ICRPD. A literature search was conducted for studies published in English or Korean until September 2023, using the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines.

Results: A total of 216 journals were searched, and 31 eligible studies were selected based on the inclusion and exclusion criteria. One systematic review included five case reports of ICRPD. Nine retrospective studies evaluated implant survival/success rate, implant failure cases, marginal bone loss, periodontal status, clinical complications, and patient satisfaction. Twenty-one case reports published in Korea showed good prognoses.

Conclusion: According to the findings of this systematic review, ICRPD has a reasonable survival/success rate, minimal bone loss, and high patient satisfaction.

Purpose: This cone-beam computed tomography (CBCT) study aimed to analyze the anatomical characteristics of alveolar bone at mandibular first molar (MFM) and their implications for immediate implant placement surgery.

Materials and methods: 100 patients with 140 MFMs were reviewed retrospectively. We first performed a 3D reconstruction of the patient's CBCT data to determine a reference plane with ideal implant placement and orientation. The following parameters of MFM region were analyzed: mesial-distal socket size (MD-SS), buccal-lingual socket size (BL-SS), root furcation fornix to inferior alveolar nerve (IAN) distance (RF-I), interradicular bone thickness (IRB), mesial/distal root apex to the IAN distance (MRA-I/DRA-I), thickness of the buccal/lingual bone of the mesial root (MR-B/MR-L), thickness of the buccal/lingual bone of the distal root (DR-B/DR-L).

Results: The MD-SS of MFM was 8.74 ± 0.76 mm, and the BL-SS was 8.26 ± 0.72 mm. The MR-B, DR-B was 1.01 ± 0.40 mm and 1.14 ± 0.50 mm, and the difference was statistically significant (P = .001). The values of the MR-L, DR-L were 2.71 ± 0.78 mm and 3.09 ± 0.73 mm, and the difference was also statistically significant (P < .001). The mean distance of RF-I was 15.68 ± 2.13 mm, and the MRA-I was 7.06 ± 2.22 mm, which was greater than that of DRA-I (6.48 ± 2.30 mm, P < .001). The IRB at 2 mm, 4 mm apical from the furcation fornix, and at apex level was 2.81 ± 0.50 mm, 3.30 ± 0.62 mm, and 4.44 ± 1.02 mm, respectively.

Conclusion: There is relatively sufficient bone mass in interradicular bone in height, but an adequate width is lacking for the bone between the mesial and distal root after the extraction of the MFM for immediate implantation. The thickness of the MFM buccal bone is relative thin, especially for the mesial root.

Purpose: The objective of the study was to analyze the impact of cement, bonding pretreatment, and ceramic abutment material on the overall color results of CAD-CAM ceramic crowns bonded to titanium-based hybrid abutments.

Materials and methods: For single implant restoration of a maxillary lateral incisor a total of 51 CAD-CAM-fabricated monolithic lithium disilicate crowns were fabricated and subsequently bonded onto 24 lithium disilicate Ti-base abutments, 24 zirconia Ti-base abutments and 3 resin abutment replicas as a control group. The 48 copings were cemented with three definitive and one provisional cement on both grit-blasted and non-blasted Ti-bases. The color of each restoration and surrounding artificial gingiva was measured spectrophotometrically at predefined measuring points and the CIELAB (ΔE_ab) color scale values were recorded.

Results: The color outcome of ceramic crowns bonded to hybrid abutments and soft tissues was affected differently by cements of different brands. Grit-blasting of Ti-bases prior to cementing CAD-CAM copings affected the color results of all-ceramic crowns. There was a significant difference (P = .038) for the median ΔE value between blasted and non-blasted reconstructions at the cervical aspect of the crown. Full-ceramic crowns on zirconia Ti-base abutments exhibited significantly lower ΔE values below the threshold of visibility (ΔE 1.8). In all subcategories tested, the use of a highly opaque temporary cement demonstrated the lowest median ΔE for both the crown and the artificial gingiva.

Conclusion: Various cements, core ceramic materials and airborne particle abrasion prior to bonding can adversely affect the color of Ti-base supported ceramic crowns and peri-implant soft tissue. However, zirconia CAD-CAM copings and an opaque cement can effectively mask this darkening.

Purpose: The aim of this prospective clinical study was to compare the influence of palatal vault forms on accuracy and speed of intraoral (IO) scans in completely edentulous cases.

Materials and methods: Based on the palatal vault form, participants were divided into three equal groups (n = 10 each); Class I: moderate; Class II: deep; Class III: flat palatal vault. A reference model was created for each patient using polyvinylsiloxane impression material. The poured models were digitized using an extraoral scanner. The resultant data were imported as a solid CAD file into 3D analysis software (GOM Inspect 2018; Gom GmbH, Braunschweig, Germany) and aligned using the software's coordinate system to determine its X, Y, and Z axes. Five digital impressions (DIs) of maxilla were captured for each patient using an intraoral scanner (TRIOS; 3Shape A/S, Copenhagen, Denmark) and the resultant Standard Tessellation Language (STL) scan files served as test models. Trueness was evaluated by calculating arithmetic mean deviation (AMD) of the vault area between reference and test files while precision was evaluated by calculating AMD between captured scans to measure repeatability of scan acquisition. The scan time taken for each participant was also recorded.

Results: There was no significant difference in trueness and precision among the groups (P = .806 and .950, respectively). Average scan time for Class I and III palatal vaults was 1 min 13 seconds and 1 min 37 seconds, respectively, while class II deep palatal vaults showed the highest scan time of 5 mins.

Conclusion: Palatal vault form in edentulous cases has an influence on scan time. However, it does not have a substantial impact on the accuracy of the acquired scans.

Purpose: This in vitro study was conducted to investigate the accuracy of intraoral scanner (IOS) for recording maximal intercuspal position (MIP) and border positions of the mandible.

Materials and methods: Maxillary and mandibular master casts were articulated in MIP, protrusive, and lateral interocclusal position sequentially on a semi-adjustable articulator. For each articulation relation, sites of occlusal contacts (SOCs) and sites of clearance (SCs) were identified on the master casts with articulating paper (reference sites). IOS was used to take full arch scans and nine virtual interocclusal records (VIRs) for virtual articulation of models. Virtual SOCs and SCs were detected with 3D processing software and compared to those identified with the articulating paper. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated for each articulation relation.

Results: For MIP, IOS showed adequate sensitivity and NPV of 100%, and specificity and a PPV of 99%. For protrusive position, the IOS showed a sensitivity and a NPV of 100%, a high PPV of 86%, and a specificity of 83%. For lateral positions, the specificity and the PPV were high (93% and 79%, respectively), but the sensitivity and the NPV were below the clinically acceptable limits (28% and 56%, respectively).

Conclusion: IOS displayed clinically acceptable accuracy for recording MIP and protrusive border mandibular position. However, IOS had less accuracy for lateral border mandibular position.

[This corrects the article on p. 67 in vol. 16, PMID: 38694192.].

Purpose: The purpose of this diagnostic study was to assess the accuracy and time efficiency of a digital method to draw the denture foundation extension outline on preliminary casts compared with the conventional technique.

Materials and methods: A total of 28 preliminary edentulous casts with no anatomical landmarks were digitized using a laboratory scanner. The outlining of the entire basal seat of the denture was performed on preliminary casts and digitized. Casts with no extension outline were digitized and outlines were drawn using software (DWOS, Straumann). The accuracy of the extension outlined between both techniques was evaluated in the software (GOM Inspect; GOM GmbH) by file superimposition. Specificity and sensitivity tests were applied to measure accuracy. The paired t-test (95% CI) was used to compare the mean total area and the working time.

Results: The accuracy ranged from 0.57 to 0.92. The buccal and labial frenulum showed a lower value in the maxilla (0.57); while the area between the retromolar pad and buccal frenulum (0.64) showed a lower score in the mandible. The maxillary denture foundation and the working time for both arches were significantly longer for the digital method (P < .001).

Conclusion: The denture foundation extension outline exhibited a sufficiently excellent accuracy for the digital method, except for the maxillary anterior region. However, the digital method required a longer working time.

Purpose: This study assessed the effect of storage time on chemical structure of a single-bottle and a two-bottle experimental ceramic primer and micro-shear bond strength (µSBS) of composite to ceramic.

Materials and methods: This study was conducted on 60 sintered zirconia and 60 feldspathic porcelain blocks. Half of the specimens (n = 30) were subjected to surface treatment with the single-bottle Clearfil ceramic primer (n = 15) and two-bottle experimental primer (n = 15) after 24 hours. The remaining half received the same surface treatments after 6 months storage in distilled water. Composite cylinders were bonded to the ceramics, and they were then subjected to µSBS test. Also, the primers underwent Fourier-transform infrared spectroscopy (FTIR) after 24 hours and 6 months to assess their chemical structure. Data were analyzed with 3-way ANOVA and adjusted Bonferroni test (alpha = 0.05).

Results: The µSBS of both ceramics significantly decreased at 6 months in one-bottle ceramic primer group (P = .001), but it was not significantly different from the two-bottle experimental primer group (P = .635). FTIR showed hydrolysis of single-bottle primer, cleavage of silane and 10-MDP bonds, and formation of siloxane bonds after 6 months.

Conclusion: Six months of storage caused significant degradation of single-bottle ceramic primer, and consequently had an adverse effect on µSBS.