International Journal of Prosthodontics最新文献

Purpose: To assess and compare the clinical outcomes of three different types of all-ceramic posterior monolithic tooth-supported crowns.

Materials and methods: A total of 71 patients received 90 all-ceramic crowns randomized to be either high-translucency zirconia (ZC), high-translucency zirconia with a partial buccal veneer (ZC-V), or lithium disilicate glass-ceramic (LDS). All treatments were performed by four general dentists who were blinded to the material used. Baseline and subsequent annual evaluations were based on modified California Dental Association (CDA) criteria. A questionnaire was used to include patient-reported outcomes and to compare them to the crown quality rating performed by dentists.

Results: A total of 66 patients with 84 crowns were examined after 3 years. The survival rate was 98.8%. No crowns fractured during the observation period. One ZC-V crown failed due to loss of retention, and three complications were noted: loss of retention occurred in one ZC crown, and two ZC crowns needed to be endodontically treated. There was no significant difference between the different crowns regarding marginal integrity, surface, or anatomical form. Both patients and examining dentists rated the crowns favorably regarding esthetics, patients more than dentists.

Conclusions: All crown types used show excellent and promising clinical outcomes from a short-term perspective. Patients and dentists rate the restorations favorably concerning esthetics and function. Int J Prosthodont 2023;36:546-553.

A technique for the virtual design of a three-piece stackable auricular mold for unilateral auricular defect rehabilitation using an open-source software program is described. An optical intraoral scanner is used to scan the patient's ear on both the affected and unaffected side. To maintain the relationship between the mold parts, a stackable attachment is designed and joined to the mold. The mold is 3D printed in resin. This technique provides the patient with a precise auricular prosthesis with perfect thickness, adaptation, and appearance. The workflow introduced in this technique could be considered as an alternative way to fabricate auricular prostheses in a much shorter clinical and laboratory time compared to the conventional workflow. Int J Prosthodont 2023;36:637-641.

Purpose: To investigate the optimal combination of factors (finish line, scanning, and ceramic processing) to achieve the best values of both adaptation and fracture load for lithium disilicate crowns (LD).

Materials and methods: Two abutment preparations, chamfer (C) and rounded shoulder (S), were produced with a dentin analog material and scanned with either extraoral (E) or intraoral (I) scanners. Images were processed using CAD software to design a premolar. Blocks of LD were milled using a CAD/CAM system (CAD). For the press technique (PRE), crowns were first 3D printed using a polymeric material, then heat-pressing protocol was performed. Design of experiments was used to plan four experimental groups (n = 10): CAD-CI, CAD-SE, PRE-CE, and PRE-SI. Two dependent variables were analyzed: adaptation, measured using the replica technique; and fracture load of the cemented crowns. Fractographic analysis was performed. Data were analyzed using ANOVA and regression statistical analyses.

Results: There was no significant effect of the scanning method and finish line on the gap thickness in the different regions. For the processing method, CAD resulted in larger gap thickness in the occlusal, axial angle, and marginal areas and a smaller gap in the axial area (P < .001). The investigated factors had no effect on the fracture load. Yet, PRE-CE was considered the optimum design because it achieved 100% of the desired fracture load (>1000 N) and 40% adaptation (< 200 µm).

Conclusions: The optimum combination of factors for all-ceramic crowns is chamfer abutment preparation, extraoral scanning, and the press technique (combined with 3D printing). Int J Prosthodont 2023;36:e103-e118.

Purpose: To compare the adaptation of single metal-ceramic crowns (MCCs) fabricated with three different methods: lost-wax metal casting (LMC), milling of hard cobalt-chromium (HCC) blanks, and milling of soft presintered cobalt-chromium (SCC) blanks.

Materials and methods: In this double-blind parallel randomized clinical trial, 60 single MCCs were fabricated using three different methods. Adaptation of the copings was evaluated radiographically, visually, and microscopically. Data were compared among the three groups using the Kruskal-Wallis test, followed by the Dunn post hoc test, one-way ANOVA, and paired t test (α = .05).

Results: Radiographic data showed that the frequency of crowns with no marginal discrepancy was significantly higher in the SCC group than the LMC group. Evaluation of marginal adaptation with an explorer revealed that crowns with excellent marginal adaptation had lower frequency in the LMC group than the HCC and SCC groups. In the silicone replica technique, the recorded data revealed no significant difference. Application of porcelain veneering did not affect the adaptation of the copings.

Conclusions: The SCC and HCC groups showed better clinical outcomes compared to the LMC group. However, all MCCs fabricated with the LMC method, milling of HCC blanks, and milling of SCC blanks had acceptable clinical adaptation. Int J Prosthodont 2023;36:581-587.

Albers-Schönberg disease is a rare bone syndrome characterized by increased bone density and infectious complications after dental extraction or minor surgery. The prosthodontic management of such edentulous patients with osteomyelitis is very challenging and requires special strategies due to a high risk of failure and worsening of the condition. This clinical report describes the rehabilitation of a 31-year-old edentulous woman presenting with Albers-Schönberg disease, secondary chronic osteomyelitis, maxillary hypoplasia, compromised oral conditions, temporomandibular disorders, and psychologic distress. The treatment included a mandibulectomy and removable prostheses. A crucial element for the successful long-term treatment and quality of life improvement observed in this patient was the 1-year transitional phase with interim dentures and frequent follow-up appointments. The complications and management proposed during a 10-year follow-up are presented. Int J Prosthodont 2023;36:642-648.

Purpose: To evaluate the fracture-behavior of monolithic crowns made of lithium disilicate (IPS e.max CAD, Ivoclar Vivadent; IniBal LiSi Block, GC Dental) and zirconia-reinforced lithium silicate (Celtra Duo, DeguDent; VITA Zahnfabrik) materials before and after cyclic fatigue aging.

Materials and methods: Four groups (n = 22/group) of CAD/CAM fabricated upper incisor crowns were produced. All crowns were luted on metal dies with an adhesive dual-cure resin cement (G-CEM LinkForce, GC Dental). Half of the crowns in each group (n = 11) were statically loaded until fracture, without aging. The remaining crowns were subjected to cyclic fatigue aging for 120,000 cycles (Fmax = 220 N) and then loaded statically until fracture. The fractured models were then visually examined. Scanning electron microsopy (SEM) and energy-dispersive spectroscopy (EDS) were used to evaluate the microstructure of CAD/CAM ceramic materials. The data were statistically analyzed with two-way ANOVA followed by the Tukey HSD test (α = .05).

Results: Before cyclic aging, there was no statistically significant difference in load-bearing capacity among the four groups (P = .371). After cyclic aging, load-bearing capacity significantly decreased for all groups (P = .000). While the e.max CAD blocks had significantly higher load-bearing capacity (1061 ± 94 N) than both monolithic ceramic crowns (load-bearing capacities of the groups) (P < .05), no significant difference was obtained with the Initial LiSi Block group (920 ± 140 N) (P = .061).

Conclusions: The mechanical performance of monolithic ceramic crowns fabricated from lithium disilicate was befer than zirconia-reinforced lithium silicate after cyclic fatigue aging. Int J Prosthodont 2023;36:e29-e37.

Purpose: To report the results of a 2020 international survey of the most commonly used materials and techniques for the fabrication of extraoral maxillofacial prosthetics, and to assess the use of 3D technology.

Materials and methods: A 43-question survey was administered via Qualtrics to the members of the American Academy of Maxillofacial Prosthetics (AAMP), the International Anaplastology Association (IAA), and the International Society of Maxillofacial Rehabilitation (ISMR). The use of current 3D technology in the fabrication of maxillofacial prostheses as well as barriers to care such as patient cost and insurance coverage were also assessed.

Results: In total, 134 respondents (13%) completed the survey; 96 (73%) reported that they were currently fabricating maxillofacial prostheses and were thus included in the survey. The majority of respondents reported currently using Silastic MDX4-4210 BioMedical Grade Elastomer (DuPont) with either Silastic Medical Adhesive Silicone Type A or Silastic MDX4-4210 crosslinker. Incorporating the use of current CAD/CAM technology was reported by a majority of respondents (58%; 45/77); however, a small cohort (33%, 15/45) reported they were still experimenting how best to use technology. A total of 39 clinicians (49%) reported that facial prosthetics were most often paid for by the patient (fee for service), with the fees ranging from $10 to $5,500 USD.

Conclusions: The results of this survey indicate that current CAD/CAM technology has been adopted and incorporated into the design and fabrication of maxillofacial prostheses. More research is needed to advance CAD/CAM technology as well as the physical and mechanical properties of materials in maxillofacial prosthetics and anaplastology clinical practice. Int J Prosthodont 2023;36:570-580.

Purpose: To compare characteristics of temporomandibular disorders (TMDs) in patients with rheumatoid arthritis (RA) to patients without RA.

Materials and methods: The sample included 80 patients (aged 33 to 73 years; 88% women and 22% men) with 40 in each group. An international diagnostic protocol for TMDs was followed.

Results: Arthralgia was the most prevalent TMD in the RA group. Orofacial pain was more common in the RA group than in the controls (42.5% vs 15%, P = .031), with higher chronic pain grade and pain intensity (P ≤ .005). Somatization and depression were also increased (P < .001). In multiple logistic regression analysis, arthralgia (OR: 6.4; 95% CI: 1.1 to 37.1; P = .038) and age ≥ 55 years were predictors of RA (OR: 3.9; 95% CI: 1.4 to 10.8; P = .009) when controlling for the effects of biological sex and pain intensity. TMDs were related to 7.4 times higher odds for presence of orofacial pain, while RA was related to 3.4 times higher odds for pain.

Conclusions: RA patients experienced more orofacial pain and higher pain intensity, somatization, and depression compared to healthy individuals. Pain is more influenced by TMDs than by RA. Int J Prosthodont 2023;36:630-636.

Purpose: To evaluate the dimensional discrepancy between the diagnostic wax-up and the resulting mock-up.

Material and methods: A maxillary model with misaligned teeth was scanned, and an initial cast was 3D printed. A total of 60 identical casts were 3D printed from the initial one after scanning. Based on a digital additive veneer wax-up on the six anterior teeth, 10 more casts were 3D printed. The specimens were allocated to seven groups (n = 10) as follows-group 1: transparent silicone matrix with a flowable light-cured composite resin; group 2: same as group 1 but with the addition of a prefabricated transparent tray; group 3: silicone impression putty (65 Shore A) and light-body silicone impression material with a dual-cured bisacryl resin; group 4: same as group 3 but without the light-body silicone; group 5: silicone laboratory putty (92 Shore A) with a dual-cured bisacryl resin; group 6: silicone laboratory putty (92 Shore A) with PMMA; group 7: wax-up casts (control). Scans from the mock-ups were coregistered, segmented, and superimposed with the scans from the wax-up. The difference between the mock-up and the wax-up was quantified by morphologic operations. Results were analyzed by Kruskal-Wallis test and Dunn post hoc test (P < .05).

Results: All mock-ups were larger than the wax-up. Significant differences were found for every labial surface third. The incisal third was the least accurate third while the middle third the most accurate. The most accurate were groups 2 and 5, and the largest discrepancy was observed in group 6.

Conclusions: The analog mock-up differs dimensionally from the wax-up, regardless of the technique/materials used.

Purpose: To investigate the clinical results of single-tooth ceramic crowns in the posterior region produced from three different monolithic materials.

Materials and methods: A total of 36 posterior single-tooth crowns were fabricated from lithium silicate glass-ceramic (LSGC; n = 12), lithium disilicate glass-ceramic (LDGC; n = 12), and polymer-infiltrated ceramic network (PICN; n = 12) in 27 patients. Restorations were evaluated for prosthetic and periodontal criteria at baseline (0) and after 6 and 12 months. Prosthetic evaluation was performed according to the modified United States Public Health Service (USPHS) criteria, and probing depth (PD), clinical attachment level (CAL), gingival bleeding time index (GBTI), and gingival (GI) and periodontal indices (PI) were evaluated in the periodontal assessment. Friedman and Kruskal-Wallis tests were used for statistical analyses (P = .05).

Results: All restorations were evaluated according to survival and success rates. No dropouts occurred. The survival rate of all three materials was 100% after 1 year. However, in the PICN group, a statistically significant difference was found between baseline and 12 months for color match (from A to B) and surface texture (from A to C; P < .001).

Conclusions: Although long-term clinical follow-up periods are needed, all three ceramics showed clinically acceptable survival and success rates over 1 year. The ceramics evaluated in the present study could be preferred for single-tooth full-crown restorations in the posterior region.