Search Results (148)

Background/Objectives: Recently, a novel magnetic attachment system was introduced to improve performance. Using the same technology, a new ultra-thin magnetic attachment (UTMA) was possible to produce. This study aimed to evaluate the feasibility of a magnet-retained telescopic partial denture (MTPD) utilizing the new UTMA. Methods: This in vitro study was performed using a titanium master model representing prepared lower first-premolar and second-molar abutment teeth. The inner crowns (ICs) (h: 4 mm, 4° taper) and four-unit MTPDs were fabricated via computer-aided design/computer-aided manufacturing (CAD/CAM) using zirconia. A Ø4 mm UTMA system (magnet assembly and keeper thickness: 0.6 mm and 0.4 mm, respectively) was cemented into the MTPD and the ICs using dual-cure resin cement. A load of 100 N was applied along with 10,000 insertion–removal cycles. The MTPD retentive force was measured before and after every set of 1000 cycles. Stability tests and surface morphology evaluations were conducted before and after cycling. A paired t-test (α = 0.05) was used to observe statistical differences. Results: The average retentive force of the MTPD was 6.86 ± 0.63 N and did not change significantly (p > 0.05) following the load cycles (6.66 ± 0.79 N). The MTPD demonstrated adequate stability under the occlusal load. Minimal deformations were observed on the magnet assemblies, keepers, ICs, and MTPD surfaces after the load tests. Conclusions: Considering the limitations of this study, an MTPD utilizing novel UTMAs fabricated through a digital workflow demonstrated adequate retentive force, stability, and durability for clinical use. Full article

This study aimed to evaluate the effect of different manufacturing techniques and thermal aging on the fracture resistance of provisional crowns and fixed partial dentures. Methods: A total of 60 provisional crowns and 60 provisional fixed partial dentures were fabricated using three manufacturing techniques: conventional manufacturing (CM), subtractive manufacturing (SM), and additive manufacturing (AM). An index created from SM-manufactured restorations was used to produce the CM group. Artificial abutments were created by duplicating scanned phantom teeth using model resin. Half of the restorations (n = 10 per group) were subjected to thermal aging (5–55 °C, 5000 cycles). The fracture resistance values of the specimens were tested using a universal testing machine. Data were analyzed using a two-way ANOVA and Tukey’s post hoc tests (α = 0.05). The highest mean fracture resistance was observed in the SM group without aging, both for crowns (1645.4 ± 346.8 N) and fixed partial dentures (1291.13 ± 564.15 N). The two-way ANOVA revealed statistically significant differences among the groups, and thermal aging significantly reduced the fracture resistance (p < 0.05). Both the manufacturing method and thermal aging significantly influenced the fracture resistance of provisional crowns and fixed partial dentures. In fixed partial dentures, a significant effect of aging was associated with the reduced durability of restorations fabricated using the subtractive manufacturing method. Full article

This study aimed to evaluate prosthetic complications, implant survival rates, and marginal bone loss in implant-supported monolithic restorations compared to metal-ceramic restorations. The study was registered in PROSPERO (CRD420251022336) and conducted following the Cochrane Handbook for Systematic Reviews of Interventions and PRISMA guidelines. A systematic search was conducted in the electronic databases MEDLINE/PubMed, Web of Science, Scopus, Embase, and ProQuest for articles published up to December 2024. The inclusion criteria comprised studies evaluating only randomized clinical trials that evaluated implant-supported monolithic restorations directly compared to metal-ceramic restorations, considering any type of ceramic material and regardless of the fixation system (screw-retained or cemented), with a minimum follow-up of one year. A meta-analysis was performed using RevMan 5.4 software, and the risk of bias and certainty of evidence were assessed using the RoB 2.0 and GRADE tools, respectively. A total of six studies were included, all of which exclusively evaluated monolithic zirconia single crowns over follow-up periods ranging from 1 to 3 years. None of the included studies evaluated fixed partial dentures or restorative materials other than monolithic zirconia. In total, 267 patients (mean age range: 18–57 years) were analyzed, with a total of 174 implant-supported monolithic zirconia crowns and 165 metal-ceramic single crowns in the posterior region (premolars and molars). The meta-analysis revealed that implant-supported monolithic zirconia single crowns exhibited significantly fewer prosthetic complications compared to metal-ceramic single crowns (p < 0.0001; Risk Ratio [RR]: 0.26; Confidence Interval [CI]: 0.14–0.47). However, no statistically significant differences were observed between implant-supported monolithic zirconia and metal-ceramic single crowns regarding implant survival rates (p = 0.36; RR: 1.66; CI: 0.56–4.94) or marginal bone loss (p = 0.15; Mean Difference [MD]: −0.05; CI: −0.11–0.02). The risk of bias assessment indicated that four studies had a low risk of bias. However, the certainty of evidence was classified as low for prosthetic complications and implant survival rates and very low for marginal bone loss. Within the limitations of this review, it can be concluded that implant-supported monolithic zirconia single crowns can be considered a favorable treatment option as they show comparable implant survival and bone stability to metal-ceramic crowns, with a potential reduction in short-term prosthetic complications such as screw loosening and ceramic chipping. However, due to the limited number of studies included and low certainty of evidence, further long-term research is still needed to confirm their clinical performance over time. Full article

Purpose: The aim of this study was to evaluate the long-term clinical results of two different implant–abutment connection types (screw-retained/Morse locking taper), marginal bone loss, and complications in prosthetic restorations. Materials and Methods: In 2017–2018, 579 implants and 242 implant-supported restorations applied to 137 patients were included in the study. Patients were recalled every six months, clinical evaluations were accomplished, and complications were recorded. When examining the distribution of prosthetic restorations by type, it was determined that 38 (15.70%) were single crowns, 136 (56.19%) were fixed partial cement-retained bridge restorations, 53 (21.90%) were fixed partial screw-retained bridge restorations, and 15 (6.19%) were overdenture prostheses. Findings: Overall, complications included eighteen (21.68%) retention losses, nineteen (22.89%) instances of screw loosening, twenty-one (25.30%) veneer ceramic fractures, three (3.61%) acrylic base fractures, fourteen (16.87%) cases of peri-implantitis, and eight (9.64%) implant losses. Conclusions: Differences in complication rates were observed between implants with different implant–abutment connection designs. While no significant differences were found regarding annual mesial and distal marginal bone loss for implants with conical locking connections, a significant difference was detected in those with screw-retained connections. In both implant groups, mesial and distal marginal bone loss progressed gradually over the follow-up period. Full article

Background: The treatment of head and neck cancer primarily involves surgical tumor removal combined with radiotherapy and/or chemotherapy. It often leads to significant side effects, impacting the anatomical structures of the oral cavity and resulting in major functional, esthetic, and socio-relational alterations. Case presentation: This clinical report aims to demonstrate the effectiveness of a hospital-based approach incorporating general anesthesia (GA) and computer-aided design and manufacturing (CAD/CAM) technology in the oral rehabilitation of a 58-year-old woman in remission from intraoral squamous cell carcinoma of the mandibular symphysis. The patient presented with oral pain, radiation-induced caries, reduced occlusal vertical dimension, and severely compromised teeth. Treatment Approach: The treatment plan included the removal of two non-restorable teeth, root canal treatment for the remaining teeth, and the placement of ceramic crowns and a partial removable prosthesis. Due to the complexity of the case and the patient’s limitations, the treatment was performed under GA, allowing for a staged approach. Digital technologies, including intraoral scanning and CAD-CAM, enhanced precision and patient comfort. This approach facilitated tooth preservation and minimized the number of extractions while achieving satisfactory functional and esthetic outcomes. Conclusion: The case highlights the value of GA and digital techniques in managing special-needs patients with a history of irradiated head and neck cancer. Full article

(1) The aim of this in vitro study was to investigate the handling of proximal-cervical undermined enamel margins on the adhesive performance of differently fabricated and differently cemented ceramic inlays and partial crowns (2) Methods: 192 extracted third molars received MOD (n = 96) and partial crown (n = 96) preparations. A mesial 2 × 2 × 4 mm cervical groove was created in dentin to simulate a deeper (dentin) caries excavation. This dentin groove was either left (G/groove), filled with composite (F/filling), or completely removed (D/dentin). Distal proximal boxes did not receive a groove and served as controls within the same tooth. Labside (e.max Press) restorations additionally went through a temporary phase. Labside and chairside (e.max CAD) inlays and partial crowns were then adhesively luted with Syntac/Variolink Esthetic (SV) or Adhese Universal/Variolink Esthetic (AV). Initially, and again after thermomechanical loading (TML: 1 million cycles at 50 N, 25,000 thermocycles at 5 °C/55 °C), specimens were molded and the resulting 24 groups of epoxy replicas (n = 8) were gold-sputtered and examined for marginal gaps using scanning electron microscopy (200× magnification). Light microscopy (10× magnification) was used to measure proximal cervical crack propagation in adjacent enamel. (3) Results: Regardless of the adhesive system, D groups generally showed significantly lower marginal quality (79–88%; p < 0.05), with the universal adhesive performing better than the multi-step adhesive system (p < 0.05). Subgroups G and F were similar in marginal quality (94–98%; p > 0.05) and not worse than the controls (p > 0.05) regardless of the adhesive system, but showed less cracking in F than in G (p < 0.05). In general, fewer cracks were observed in chairside CAD/CAM restorations than in laboratory-fabricated restorations (p < 0.05). Partial crowns showed better marginal quality (96–98%) and less cracking than inlays (p < 0.05). (4) Conclusions: If the dentin level is lower than the enamel level in ceramic preparations after caries excavation in the proximal box, the resulting undermined enamel should not be removed. In terms of enamel integrity, partial crowns outperformed inlays. Full article

Background: Drug-induced gingival enlargement is a commonly documented adverse effect in patients administered with calcium antagonist medications. Nifedipine is the medicine most frequently linked to instances of gingival enlargement; nevertheless, amlodipine, likewise a calcium antagonist, can elicit this adverse effect. This case report aims to detail a case of amlodipine-induced gingival hyperplasia, emphasizing the significance of a multidisciplinary approach and outlining its therapy across various surgical phases. Methods: A 48-year-old hypertensive patient using amlodipine therapy presents with aberrant gingival tissue growth in the upper arch. Intraoral examination reveals localized inflammation and tissue enlargement in the papillae areas of the upper arch gingiva, leading to partial covering of the dental crowns. The patient experienced painful sensations and episodes of spontaneous bleeding in the enlarged gingival tissue. Following an initial professional dental hygiene treatment, which included root planning in the upper quadrants, and in consultation with the referring cardiologist, it was determined to discontinue amlodipine and initiate a replacement therapy with olmesartan medoxomil. Fifteen days following the cessation of amlodipine, surgical excision of the thickened interdental gingival tissues in the anterior region was conducted to obtain biopsies for histological confirmation of the observed pathological condition. Results: Histopathological examination validated the diagnosis of drug-induced gingival enlargement, characterized by chorion fibrosis and significant lymphoplasmacytic infiltration. Specifically, parakeratotic and acanthotic characteristics were seen in the gingival epithelium. Adjacent to the inflammatory regions, fibrosis was noted, along with the presence of cytoid bodies, which are typically linked to pathological diseases driven by inflammatory processes. These histological characteristics were consistent with the diagnosis of drug-induced gingival enlargement. Conclusions: A multidisciplinary approach involving the treating physician, dentist, and hygienist, incorporating drug replacement and targeted oral hygiene sessions, is crucial for the management and resolution of calcium channel blocker-induced gingival enlargement. Full article

Background/Objectives: For dental implant treatment to be successful, esthetics, functionality, and cleanability are all required of the superstructure, which is the final prosthesis. Screw fixation and cementation have been the conventional methods of choice for the crown prosthesis of implants, but these individual methods cannot fulfill all the requirements. Methods: As a solution to this problem, we have devised a new implant superstructure restoration method called the inlay covering esthetic technique, which uses computer-aided design/computer-aided manufacturing inlays. Results: It involves the placement of an inlay covering the access hole in a highly translucent partially stabilized zirconia crown. Conclusions: This technique, demonstrated in this clinical case study, expands the indications for implant treatment and improves the oral quality of life of patients. This case report describes a novel esthetic technique for restoring dental implant access holes. Full article

This study compares the mechanical properties of 5-mol% yttria partially stabilized zirconia (5Y-PSZ) materials, designed for 3D printing or milling. Three 5Y-PSZ materials were investigated: printed zirconia (PZ) and two milled zirconia materials, VITA-YZ-XT (MZ-1) and Cercon xt (MZ-2). PZ samples were made from a novel ceramic suspension via digital light processing and divided into three subgroups: PZ-HN-ZD (horizontal nesting, printed with Zipro-D Dental), PZ-VN-Z (vertical nesting, printed with Zipro-D Dental) and PZ-VN-Z (vertical nesting, printed with Zipro Dental). Key outcomes included biaxial flexural strength (ISO 6872) and Vickers hardness (n ≥ 23 samples/subgroup). Microstructure and grain size were analyzed using light and scanning electron microscopy. Printed specimens exhibited biaxial flexural strengths of 1059 ± 178 MPa (PZ-HN-ZD), 797 ± 135 MPa (PZ-VN-ZD), and 793 ± 75 MPa (PZ-VN-Z). Milled samples showed strengths of 745 ± 96 MPa (MZ-1) and 928 ± 87 MPa (MZ-2). Significant differences (α = 0.05) were observed, except between vertically printed groups and MZ-1. Vickers hardness was highest for PZ-VN-Z (HV0.5 = 1590 ± 24), followed by MZ-1 (HV0.5 = 1577 ± 9) and MZ-2 (HV0.5 = 1524 ± 4), with significant differences, except between PZ and MZ-1. PZ samples had the smallest grain size (0.744 ± 0.024 µm) compared to MZ-1 (0.820 ± 0.042 µm) and MZ-2 (1.023 ± 0.081 µm). All materials met ISO 6872 standards for crowns and three-unit prostheses in posterior regions. Full article

Forest stands are developing in changeable climate conditions that influence stand health and consequently assortment quality. Narrow-leaved ash is strongly affected by dieback because of new fungal diseases. The main aim of this study was to determine the quantity and quality of produced wood assortments in dieback-affected narrow-leaved ash stands. Based on the study results, the average tree value increased with tree diameter and partially decreased with tree crown defoliation degree. The healthy (crown defoliated up to 25%) and 3A (crown defoliated from 61 to 80%) trees had significantly higher average tree values (EUR/m³) compared to the significantly defoliated 3B trees (crown defoliated from 81 to 99%) and dead trees (100% defoliated crown). The influence of stand age and share of narrow-leaved ash in stand volume were confirmed as factors influencing the average tree value. Wood chips quality remained the same regardless of tree crown defoliation degree. Based on the significance influence of the tree crown defoliation degree on the average tree value, current assortment tables should be expanded in order to achieve more accurate expected values. Full article

Sandblasting and acid etching are common procedures used to treat implant surfaces, enhancing osseointegration and improving clinical success rates. This clinical study aimed to evaluate the long-term outcomes of sandblasted and acid-etched implants. A total of 303 implants were placed in 114 partially and totally edentulous patients using a two-stage surgical technique and an early loading protocol (6–8 weeks). Clinical findings for implants and prosthetics were evaluated over a 12-year follow-up period. A total of 12 implants (3.9%) failed, with 3 failures occurring during the healing period before loading and 9 due to peri-implantitis. The cumulative survival rate for all implants was 96.1%. A total of 156 prostheses were placed on 300 implants, 87 single crowns, 45 partial fixed bridges, 9 full-arch fixed restorations, and 15 overdentures. The mean marginal bone loss was 1.18 mm. (SD. 0.64 mm.). Thirty-nine implants (13%) in twenty-four patients exhibited peri-implantitis. Technical complications, including prosthetic screw loosening or fracture, ceramic chipping, and acrylic fractures, were observed in 24 subjects (21.1%). Sandblasted and acid-etched surface implants placed in the maxilla and mandible reported favorable outcomes and stable tissue conditions with an early loading protocol. Full article

Polyetheretherketone (PEEK) has emerged as a revolutionary material in modern dentistry because of its unique combination of mechanical strength, biocompatibility, and versatility. This literature review examines the current applications and future potential of PEEK in various dental disciplines. PEEK’s favorable properties, including its low specific weight, high strength-to-weight ratio, and ability to be easily machined, have led to its adoption in prosthetics, implantology, and dental esthetic restorations. This material has shown promise for fabricating crowns, bridges, removable partial denture frameworks, and implant components. PEEK’s radiolucency and bone-like elastic modulus make it particularly suitable for dental implants and abutments. Additionally, its resistance to degradation and compatibility with various surface treatments enhances its long-term performance in the oral environment. While challenges such as bonding to other dental materials and aesthetic limitations exist, ongoing research is addressing these issues through surface modifications and composite formulations. As the dental field continues to evolve, PEEK’s adaptability and biocompatibility position it a key player in the development of next-generation dental materials and techniques, potentially transforming patient care and treatment outcomes in dentistry. Full article

Background: 3D-printed (3DP) resins for permanent restorations are increasing in availability and gaining popularity. Aesthetic stability is an issue of dental resins that may compromise the long-term success of restorations. A staining test has been performed to evaluate gloss, roughness, and color staining of a permanent 3DP resin, and the effects of repolishing. Methods: Squared specimens of one 3DP permanent resin (Crown permanent, Formlabs) have been CAD-designed and 3D-printed. After the roughness, gloss, and color measurements, they were immersed in a coffee staining bath at 44 °C for 24 h and then measured again. Subsequently, they were repolished with three different systems: prophy cup and Nupro prophy paste, HiLuster Plus 2-step, and Opti1Step Polisher 1-step polishing systems. Results: Gloss and Roughness were not significantly affected by the staining procedure. No significant changes were observed for gloss after repolishing, while one of the tested systems (prophy cup and paste) produced a worsening effect on roughness. Color was affected by the staining procedure. After repolishing, b* changes were almost completely recovered, while L* changes were recovered only partially. Conclusions: Color stability still represents a challenge, and 3DP resins for permanent use are affected. Repolishing systems should be further developed and tested. Full article

Background/Objectives: Recent research has indicated that placing dental implants in patients diagnosed with bruxism has led to higher rates of implant failure. This study aimed to provide more accurate knowledge about the relationship between bruxism and implant loss in patients (number, age, gender) with different numbers of implants and prosthetic restorations, considering the follow-up time, compared to non-bruxers. Methods: A systematic search was conducted in PubMed and Cochrane Library using the keyword combination “dental implant”, “bruxism”, and “implant failure”. This search had no language or time restrictions. Results: The review included 15 papers, which were divided into four groups. The first group focused on studies regarding implant loss regardless of the superstructure. In the second group, research on implant-supported removable prostheses was examined. The third group consisted of a single study specifically addressing implant-supported single crowns. Lastly, the fourth group comprised two studies investigating implant-supported single crowns and fixed partial dentures. Only three out of the fifteen studies failed to find a correlation between bruxism and implant failure. The meta-analysis shows a significant pooled effect across the included studies, with an odds ratio of 4.68. Conclusions: Bruxism is a probable risk factor for mechanical issues in implant-supported prostheses and implant-supported crowns. Additionally, elevated failure rates have been documented in patients with bruxism. Full article

Background: The present article describes a step-by-step maximally digitalized workflow protocol with computer-aided design and computer-aided manufacturing (CAD/CAM) in partial-arch edentulous patients rehabilitated with fixed dental prostheses and removable partial dentures (FDPs and RPDs). Methods: Facial digitalization, intraoral scans, and functional mandibular movement recordings were used to create a 4D virtual patient on commercially available CAD software. The fixed components including post-and-cores, both metal–ceramic with extra-coronal attachment and monolithic zirconia crowns, and the RPDs were manufactured by computer numerical controlled direct milling. Results: This innovative digital approach using the virtual patient and the superimposition of interim RPDs fitted in the mouth has been used to provide fixed and removable rehabilitation to the patient without clinical complications with 2 years of follow-up. Conclusions: Within the limitations of this report, the developed combined prosthesis fabrication technique allowed optimization of the production by decreasing the clinical steps and laboratory procedures in partial-arch edentulous rehabilitated with FDPs and RPDs. Full article