The International journal of prosthodontics最新文献

Purpose: To assess the impact of nano-hydroxyapatite (n-HA) coating of different concentrations on the microshear bond strength (µSBS) of zirconia ceramics to resin cements.

Materials and methods: A total of 48 Cercon Y-TZP blocks (4 × 4 × 4 mm) were randomly divided into four groups (n = 12): (1) control group, (2) 5-g n-HA coating, (3) 10-g n-HA coating, and (4) 15-g n-HA coating. The specimens were sintered at 1,250°C. The thickness of the coatings was characterized using scanning electron microscopy (SEM). Energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD) analyses were carried out to characterize the surface. All specimens were then bonded to Panavia F2.0 cement. Microshear bond testing was carried out using a universal testing machine. Stereomicroscope imaging was used to evaluate the zirconia surface failure mode. The data were analyzed using Kruskal-Wallis and Mann-Whitney tests, and P < .05 was considered statistically significant.

Results: The mean µSBS value of the 5-g n-HA-coated group with a thickness of 7.71± 2.51 µm was 28.30 ± 3.02 MPa, which was significantly higher than the control group with the mean value of 19.94 ± 1.86 MPa (P < .05). The mean µSBS value of the 10-g and 15-g n-HA groups with thicker coatings were 21.66 ± 3.63 MPa and 15.23 ± 3.34 MPa, respectively. Additionally, the main mode of failure for the 5-g n-HA group was a mixed failure. In contrast, the adhesive mode of failure was more dominant in the control group. EDS and XRD analysis revealed the formation of crystalline HA on zirconia blocks, highlighting the predominant zirconia peak at 32 degrees. The SEM analysis of the coated specimens displayed a uniform layer of n-HA coating with evident cracks filled with the resin cement. These cracks themselves can help increase the bond strength between ceramic and resin cement.

Conclusions: A thin coating of nanocrystalline hydroxyapatite on zirconia surfaces can be effective in enhancing the microshear bond strength of these ceramics to resin cements. The microshear bond strength of n-HA-coated zirconia was significantly higher compared to the untreated specimens.

Purpose: To compare the digital colorimeter program (DCM), clinical spectrophotometer (SPM), and visual color measurement (3D-Master) used in determining the color of the restoration in vivo.

Materials and methods: Color analyses were performed using three different methods from the points determined on the maxillary right and left central incisors of 15 volunteers (n = 30). Color measurement analyses were performed using the Vita Easyshade V Device from three different points on each tooth. For visual assessments, the patient was instructed to select the color closest to their natural teeth using the Vita Toothguide 3D-Master color scale. Then a cross-polarized filter and a gray reference card were used with a camera, and intraoral photographs of the volunteers were taken. All images were transferred to the computer, the data processed with the Adobe Photoshop Lightroom software were transferred to the DCM, and color measurement analyses of the teeth were performed. The average color difference between these three methods was calculated with the CIEDE2000 (ΔE00) formula. One-way ANOVA and Bonferroni tests were applied to evaluate the data, and P values equal to or less than .05 were considered statistically significant.

Results: When three different methods were compared for each tooth, no statistically significant difference was observed between the SPM and 3D-Master groups in a* coordinates or between the 3D-Master and DCM groups in b* coordinates, while a statistically significant difference was observed between all groups in L* coordinates and mean ΔE00 (P < .001).

Conclusions: Considering that the data may be affected by the limitations of the visual analysis method and the spectrophotometer, the digital analysis method, which provides quantitative data, is anticipated to assist clinicians in color measurement due to its practicality and repeatability.

Purpose: To evaluate the implementation of the AMETO register in the region of Southern Denmark and how data application relates to the following Institute of Medicine (IoM), World Health Organization (WHO), and Organization for Economic Co-operation and Development (OECD) health domains: efficiency, effectiveness, patient-centered care, timeliness, safety, and equitability.

Materials and methods: Implementation of the register was measured using patients registered by the age of 18 years. Inclusion criteria were access to the following data: type of treatment, single- or two-stage procedures, bone augmentation, implant characteristics, and suprastructure retention methods as optional measures of efficiency; treatment outcome measures, implant survival, peri-implant bone level and health, suprastructure conditions, and cosmetic results as optional measures of effectiveness; anamnestic information and Oral Health Impact Profile (OHIP)-5 questionnaires as optional measures of patient-reported outcome measures (PROMs) and patient-centered care; patient readiness for implant insertion by performed orthodontic preimplant treatment as a measure of timeliness; avoiding adverse effects of medication, allergic reactions, and tissue damage as optional measures of safety; and age, gender, ethnicity, geographic location, and socioeconomic data as optional measures of equitability.

Results: There were 227 registered patients. A total of 26 patients (25 with dental agenesis and 1 with trauma) were included, fulfilling the study's power estimate that was calculated using peri-implant bone level at 1-year follow-up. Patients lacking OHIP questionnaires, implant information, or intraoral radiographs were excluded.

Conclusions: Implementing the AMETO register was challenging. The clinical data in the AMETO register correlate well with the domains used by the IoM, WHO, and OECD.

Purpose: To compare the survival rate and the technical, esthetic, and biologic outcomes of three different materials for monolithic crowns on zirconia implants in a randomized clinical trial.

Materials and methods: A total of 44 patients were randomly divided into three groups and restored with monolithic implant-supported single crowns: zirconia (Zr), polymer-infiltrated ceramic (PIC), and polymer (P). Follow-up evaluations were conducted after 1 year. Clinical assessments included survival rates, modified United States Public Health Service (USPHS) scores, white esthetic scores (WES), plaque index (PI), bleeding on probing (BoP), and probing depth (PD).

Results: After 1 year, survival rates for monolithic Zr and PIC crowns were 100%, while the P crown group showed a survival rate of 84.6%. At baseline, the PIC crowns achieved the highest USPHS scores; however, this group also showed a noticeable decline over time. The WES remained stable for the Zr but declined significantly for the other groups due to changes in surface texture. PIC exhibited a significant increase in plaque accumulation.

Conclusions: Regarding the survival rate, no statistically significant differences were observed between the groups. However, a lower survival rate in the P crown group and superior surface stability in the Zr crowns were noted. Within the limitations of the small sample size and short follow-up period, Zr crowns may be recommended for the restoration of one-piece zirconia implants.

Clasp-retained removable partial dentures, which are selected to avoid invasive dental implant placement surgery and the challenges of cleaning around fixed dental prostheses, remain a common option for replacing missing teeth. However, the clasps are visually unappealing, and patients demand more esthetic treatment options. Telescopic crowns, a more esthetic alternative to clasp-retained removable partial dentures, allow for better oral hygiene maintenance. This case report describes a combination of telescopic crowns and a CAD/CAM-fabricated zirconia removable dental prosthesis. This technique offers an esthetic and minimally invasive solution for patients seeking to restore their smiles and maintain better oral hygiene.

Purpose: To determine which biomaterials are referred to as hybrid ceramics and to describe their principal properties, when available.

Materials and methods: Two reviewers executed a literature search up to June 15, 2024, in three electronic databases: PubMed, Web of Science, and Scopus. All commercial names of biomaterials labeled as hybrid ceramic were retrieved if pertinent to the dental prosthesis. Articles referring to hybrid ceramic abutments were excluded.

Results: Overall, 771 studies mentioning a hybrid ceramic were identified, and 226 were selected for this bibliometric study. A total of 25 biomaterials have been identified labeled as hybrid ceramics, including 4 experimental biomaterials, 2 indirect lutable composites, 3 glass- ceramics, 2 printable permanent crown resins, and 14 resin-based CAD/CAM blocks. Their mechanical, optical, and biologic properties have been described when available.

Conclusions: Hybrid ceramics are popular in the research field yet are often mislabeled. A new, detailed classification is needed.

Purpose: To address the challenges of obtaining accurate digital impressions for the fabrication of fixed restorations on multiple implants in full-arch edentulous cases.

Materials and methods: An approach to the use of extended design scan bodies (EDSBs) and advanced digital technologies in full-arch implant rehabilitation is presented. Clinical and laboratory treatment sequences are illustrated, focusing on intraoral scanning, restorative materials, and digital fabrication techniques.

Results: EDSBs provide accurate digital impression results, maintaining precision over longer distances and proving effective for both fixed and removable implant restorations.

Conclusions: Using EDSBs with L-shaped and T-shaped extensions creates a stable reference framework during scanning, overcoming the lack of reliable landmarks on edentulous mucosa and enhancing digital impression accuracy and clinical outcomes.

Purpose: To investigate the neuromuscular position of the mandible in the fifth and final part of a comprehensive investigation of the positions of the temporomandibular joint condyles.

Materials and methods: The neuromuscular condylar positions were recorded by four independent operators in 81 fully dentate subjects with healthy oral function using a central bearing point system and rapid closing movements. The most frequent adduction point was determined, and the recordings were repeated twice for each subject. The subjects' maxillary casts were mounted in an articulator using an individual facebow transfer, and subsequently the mandibular casts were mounted with a central bearing point registration on the tip of the Gothic arch, ie, in centric condylar position (CR). A custom-made electronic measuring articulator was used to determine the spatial distance between the condyles in centric relation, maximal occlusion, and the newly determined neuromuscular position.

Results: The reproducibility of the neuromuscular registrations was on average 0.52 ± 0.16 mm (range 0.04 to 2.53 mm) with the right and left side averaged. The average spatial distance of the condyles between maximal intercuspal position (MI) and neuromuscular position was 0.88 ± 0.30 mm (range 0.12 to 5.98 mm), again averaged for the right and left sides, whereas that between the CR and the neuromuscular position was 0.83 ± 0.27 mm (range 0.10 to 7.89 mm).

Conclusions: The neuromuscular mandibular position is neither identical to MI nor to CR. It can therefore be concluded that the registration of the neuromuscular adduction field should not be recommended for prosthodontic restorations in dentate or edentulous patients.

Purpose: To assess the impact of toothbrushing and thermocycling on color, opalescence, fluorescence, and surface of extrinsically stained CAD/CAM ceramics.

Materials and methods: Specimens (n = 20) of VITA Mark II (VBII), VITA Suprinity (SUP), and IPS e.max ZirCAD (ZIR) were stained and glazed, then divided into two groups based on dentifrice (n = 10; conventional or whitening). Aging was simulated via 100,000 toothbrushing cycles followed by 12,000 cycles of thermocycling. Color differences (ΔE00) and opalescence were calculated. Images under ultraviolet (UV) lamp were obtained for fluorescence analysis. Surface roughness was analyzed using 3D laser confocal microscopy, and chemical elemental characterization was determined using energy-dispersive X-ray spectroscopy (XEDS). Statistical analyses (α = .05) included two-way ANOVA and Tukey HSD tests for ΔE00 and three-way ANOVAs with Sidak post hoc test for opalescence, fluorescence, and surface roughness. ΔE00 values were compared to perceptibility and acceptability thresholds.

Results: Higher ΔE00 were observed for VBII in the whitening group and SUP in the conventional group. All ΔE00 values remained below perceptibility. ZIR exhibited the lowest opalescence and fluorescence before and after aging. SUP and ZIR showed a significant reduction but continued to exhibit fluorescence after aging. VBII whitening and SUP conventional exhibited increased roughness. XEDS indicated that extrinsic characterization persisted on the surface with subtle changes in elemental composition after aging.

Conclusions: The findings suggest that toothbrushing with different dentifrices and thermocycling can impact the esthetic outcome and surface of stained CAD/CAM ceramics. Despite these, the materials evaluated maintained color stability and resisted the proposed aging.