Search Results (545)

Zygomatic implant perforated (ZIP) flap reconstruction offers immediate surgical rehabilitation following maxillectomy, integrating oncologic zygomatic implants with a fascio-cutaneous free flap. A critical technical challenge is safely perforating the free flap skin paddle to accommodate implants’ abutments without damaging its vasculature. Near-infrared (NIR) vein visualization technology provides real-time mapping of subcutaneous vessels and has been widely investigated in settings such as pediatric intravenous (IV) cannulation. By projecting vein pathways onto the skin, NIR visualization facilitates precise vascular identification, potentially reducing complications. We describe a case of ZIP flap reconstruction in a 25-year-old patient utilizing NIR vein visualization to preemptively locate flap vasculature and minimize the risk of vessel puncture. Our discussion places these findings within the context of the existing literature on NIR devices, underscoring their benefits of non-invasive operation, rapid imaging, and minimal need for advanced operator skills, and highlighting their utility in microvascular reconstructive surgery. Full article

Background: Implant therapy is a standard of care for long-term tooth replacement. While high survival rates have been reported for implants placed by specialists, data on outcomes achieved by Advanced Education in General Dentistry (AEGD) residents remain limited. Objectives: To evaluate the clinical performance and complication rates of dental implants placed and restored by AEGD residents under faculty supervision, and to identify factors influencing outcomes after at least one year in function. Methods: A retrospective review was conducted for implants placed between April 2012 and December 2021 at the Eastman Institute for Oral Health. Only implants with ≥1-year follow-up were included. Data included demographics, medical history, smoking status, oral hygiene, peri-implant health, and prosthetic outcomes. Logistic regression was used to assess associations between risk factors and complications. Results: Among 262 implants that survived ≥1 year, the complication rate was low: screw loosening occurred in 8.4%, crown issues in 3.4%, abutment or screw fractures in 0.4%, and early peri-implantitis in 11.5%. Examiner satisfaction was high for esthetics (82.8%) and occlusion (85.9%), and over 80% of patients rated their outcomes between 8 and 10 on a 10-point scale. Diabetes and high plaque index were significant predictors of peri-implantitis. Conclusions: Implants placed and restored by AEGD residents under structured faculty supervision achieved low complication frequencies, and strong patient satisfaction comparable to specialist outcomes. Full article

The lack of integrity at the implant–abutment junction (IAJ) contributes to problems such as micromovements and microbial colonisation. This study aimed to (1) design a protocol for assessing microleakage at the IAJ using chromophore analysis not previously reported for this specific application, (2) compare gas and dye leakage between titanium (Ti) and cobalt chrome (CoCr) abutments, and (3) assess the effect of gold (Au) gilding on sealing. Forty abutments were divided into five groups: milled Ti (MTi); cast CoCr (CCoCr); milled CoCr (MCoCr); cast CoCr with Au gilding (CCoCrG); and milled CoCr with Au gilding (MCoCrG). Samples were subjected to internal pressure within a gas and dye reservoir. Chromophore analysis via UV-Vis spectrometer was used to calculate crystal violet leakage concentrations. Scanning electron microscopy (SEM) revealed close adaptation in the MTi and MCoCr groups, contrasting with irregularities in the CCoCr groups. Correspondingly, gas leakage and dye leakage were most prevalent in the CCoCr group. Fisher exact test demonstrated a statistically significant difference (p = 0.026) between the MCoCr and CCoCr abutments. While CCoCr exhibited the highest failure rate (62.5%), Au gilding demonstrated a trend toward reduced leakage (25% failure rate), though this did not reach statistical significance (p = 0.315). This chromophore analysis represents a viable and objective assessment of IAJ integrity. Full article

Objective: To evaluate the biomechanical effects of varying posterior implant inclinations and loading protocols on peri-implant stress distribution in full-arch maxillary rehabilitations using the All-on-Four concept. Methodology: A three-dimensional finite element model of an edentulous atrophic maxilla was developed from a digital point cloud. Four implants were placed according to the All-on-Four protocol: two anterior vertical implants and two posterior implants with inclinations of 0°, 15°, 30°, or 45°. Mini-abutments and a titanium bar prosthesis were included. Material properties were assumed as homogeneous, isotropic, and linearly elastic. Immediate loading was simulated using frictional contacts (µ = 0.3), whereas delayed loading assumed complete osseointegration (bonded contacts). The models were meshed using 10-node quadratic tetrahedral elements (SOLID187) in ANSYS^®. Maximum von Mises stress in cortical bone, cancellous bone, implants, abutments, and the prosthetic bar was assessed. Results: Posterior implant tilt significantly reduced peri-implant stress. Under immediate loading, the highest stress occurred at 0° inclination in the posterior left implant (82.36 MPa) and decreased progressively with increasing tilt, reaching 33.63 MPa at 45° (≈59% reduction). Delayed loading generally produces lower stress magnitudes, particularly at extreme tilts. Anterior implants experienced lower stress levels across all configurations. Comparative analysis demonstrated that immediate loading increased stress at lower angulations, while differences between loading protocols were minimal at higher inclinations. Conclusions: Posterior implant angulation and loading protocol critically influence peri-implant stress distribution. Increased posterior tilt combined with appropriate loading reduces peak cortical bone stresses, supporting biomechanical optimization in All-on-Four maxillary rehabilitations. Full article

The accuracy of digital impressions in fully edentulous cases is limited by the lack of anatomical reference structures, potentially affecting passive fit. The effects of scanner type, impression level, and scan body splinting on accuracy remain insufficiently elucidated. This in vitro study aimed to evaluate the effects of different intraoral scanners, scanning levels, and scan body splinting methods on digital impression accuracy. A fully edentulous mandibular model with four implants (All-on-4) was fabricated, and scan bodies were connected at either the implant or multi-unit abutment level. Five splinting methods (nonsplinted, floss, orthodontic elastomeric, chain attachments, and single attachments) were applied, creating 10 experimental groups. Each group was scanned using three intraoral scanners: iTero Lumina (Align Technology, Tempe, AZ, USA), TRIOS 3 (3Shape A/S, Copenhagen, Denmark), and Medit i700 (Medit Corp, Seoul, Republic of Korea), with four repeated scans per scanner (120 scans total). Trueness and precision were assessed based on linear and angular deviations using Geomagic Control X (3D Systems, Rock Hill, SC, USA). Scanner type and scanning level significantly affected accuracy (p < 0.05), with TRIOS 3 showing higher deviations, while multi-unit abutments reduced deviations. Splinting methods showed no significant effect on accuracy, and precision did not differ among groups. Scanner type and scanning level significantly influenced digital impression accuracy; however, splinting methods yielded no significant effect. Precision remained comparable among groups. Full article

This article provides an overview of modern surface engineering technologies used in the manufacturing of dental components, with a particular focus on dental implants, abutments, and crowns. The main objective of the study is to critically evaluate selected surface treatment and coating deposition methods applied to materials such as titanium, zirconia, hydroxyapatite, and NiTi alloys, and to discuss their relevance in terms of functionality, biocompatibility, and sustainability. The analyzed technologies include anodic oxidation, alkaline oxidation, electrochemical coating deposition, and other surface modification approaches aimed at improving osseointegration, corrosion resistance, and antibacterial performance. This literature review was conducted as a narrative review supported by the PRISMA framework, using the Scopus and Web of Science databases for the period 2016–2025. The findings highlight the increasing importance of surface treatments as a key factor influencing the durability and clinical success of dental implant systems. At the same time, the results indicate that the environmental aspects and energy efficiency of manufacturing and surface treatment processes are still addressed only marginally or qualitatively in the available literature. The identified research gaps include the lack of quantitative data on the energy demand of individual technologies, the absence of standardized indicators for environmental impact assessment, and the limited number of comparative studies evaluating different surface modification techniques in the context of dental manufacturing. Overall, the results emphasize the need for a more systematic sustainability assessment of surface engineering as an integral part of modern dental manufacturing practice. Full article

Zirconium is a widely used material in the field of dentistry, employed for implants and their components as well as for the creation of crowns and veneers. Given that its biocompatibility has been studied and demonstrated in various fields of application, it is necessary to analyze how surface modification of this material influences its properties. The purpose of this study was to analyze the biocompatibility, initial adhesion (48 h), and morphology of periodontal ligament stem cells (PDLSCs) seeded on different zirconium surfaces treated with laser micropatterning, as well as plastic coverslips as a control. The Neubauer chamber was used to count the cells adhered to each of the sets, and confocal and scanning electron microscopy were employed to examine the adhesion and morphology of periodontal ligament stem cells on each of the zirconium surfaces studied. Results: Statistically significant differences were found in terms of primary cell adhesion, with sets 3 (grid topography) and 4 (channel topography) showing the most favorable characteristics for fibroblast adhesion. It was concluded that regular and moderately rough surfaces promoted better cell proliferation and development. Full article

Background/Objectives: The formation of a soft tissue seal through mucosal integration around dental implants is critical for potentially achieving long-term peri-implant health and clinical success. Understanding how different implant and abutment surfaces interact with individual layers of the oral mucosa remains limited. This study aimed to compare the differential attachment of tissue-engineered oral epithelium, connective tissue, and full-thickness human oral mucosa to various implant and abutment materials and surface topographies. Methods: Sand-blasted, large-grit, acid-etched (TiZr-SLA), machined TiZr (TiZr-M), machined zirconia (ZrO₂-M), polished zirconia (ZrO₂-P), and machined PEEK rods, along with commercially available titanium and ZrO₂ healing abutments, were inserted into 3D oral mucosal models following a 4-mm punch biopsy. Inflammation was induced using Escherichia coli lipopolysaccharide. Analyses included histology, PrestoBlue viability assay, scanning electron microscopy, and ELISA quantification of cytokines IL-1β, IL-6, and IL-8. Results: Epithelial attachment was greater on TiZr-SLA, ZrO₂-P, and PEEK-M (p < 0.05 and p < 0.01) surfaces compared with TiZr-M and ZrO₂-M. TiZr-SLA exhibited the highest connective tissue attachment (p < 0.05). Commercial titanium and ZrO₂ healing abutments demonstrated the highest post-pull PrestoBlue viability and overall soft tissue attachment. SEM confirmed cell retention on all implant surfaces. Elevated IL-1β levels were detected in models exposed to ZrO₂-M and PEEK-M, whereas IL-6 and IL-8 levels were not influenced by any material or surface topography. Conclusions: In vitro epithelial and connective tissue responses are influenced by implant material, surface topography, and design. Rough TiZr-SLA surfaces promote superior connective tissue attachment, while smooth commercial abutments support optimal overall soft tissue integration. These findings highlight the importance of surface engineering in preclinical optimization of peri-implant soft tissue attachment. Full article

Background/Objectives: The purpose of this study was to investigate the laser removal of implant-supported ceramic single crowns, focusing on their efficiency and the potential reusability of the removed restorations. Methods: Sixty single crowns made of lithium disilicate were adhesively bonded to prefabricated titanium abutments in a total of six test series (n = 10). The test series were divided according to the different spacer settings of the crowns (90 µm, 120 µm, 150 µm) and the taper of the abutments (4°, 6°). After seven days of storage in distilled water, the single crowns were removed using an erbium-doped yttrium aluminium garnet (Er:YAG) laser. The number of laser pulses needed and the time required to remove the crowns were recorded. This was followed by a micro- and macroscopic score evaluation of the crowns using a fluorescent penetration method. Results: Laser removal of all sixty crowns was successfully performed. Using a taper of 6° and a spacer of 150 µm, the crowns were removed with significantly fewer pulses (61.40 (±36.78)). The taper and spacer had a significant effect on both the microscopic (p = 0.040) and macroscopic (p = 0.035) fracture patterns. Based on the final score of the fracture analysis, 44 of the 60 crowns could be classified as potentially reusable. The remaining 16 crowns failed due to purely macroscopic (7), purely microscopic (6), and combined microscopic and macroscopic (3) fracture behavior. Conclusions: Based on the results of this study, increasing the size of the taper and spacer has proven beneficial for laser removal in terms of time efficiency and non-destructive removal of crowns. Full article

The implant–abutment connection (IAC) is a critical determinant of the mechanical and biological performance of dental implants. Connection design and insertion torque may influence fatigue resistance, micromovement, and microgap formation, thereby affecting long-term implant success. This in vitro study evaluated a novel conical implant–abutment connection under controlled mechanical loading conditions. Methods: A sequential in vitro protocol was applied. Mechanical testing was conducted according to ISO 14801:2016 and included static and cyclic loading tests of the KS implant system inserted at two different torque values (35 Ncm and 70 Ncm). High-resolution micro-computed tomography (micro-CT) was performed after mechanical loading to evaluate implant–abutment interface integrity, microstructural alterations, and microgap behavior. Results: Static and cyclic loading tests revealed no observable differences between implants inserted at 35 Ncm and 70 Ncm, with all specimens completing the loading protocols without mechanical failure. Micro-CT analysis showed no evidence of microfractures, permanent deformation, or clinically relevant alterations at the implant–abutment interface. A stable and well-sealed connection was observed for both torque values following mechanical loading. Conclusions: Within the limitations of this in vitro study, the investigated conical implant–abutment connection demonstrated stable mechanical performance and preserved interface integrity after static and cyclic loading, regardless of whether implants were placed at 35 Ncm or 70 Ncm. These findings indicate that, under the present experimental conditions, both torque levels were associated with comparable structural integrity and mechanical stability of the investigated implant–abutment connection. This study should be interpreted as a preliminary experimental investigation, designed to provide descriptive and mechanistic insights rather than statistically powered comparative conclusions. Further long-term clinical trials are required to confirm these preliminary results. Full article

Prosthetic factors, including abutment angulation and the crown–implant ratio (CIR), have been suggested to influence peri-implant marginal bone loss; however, their long-term effects remain unclear. This study aimed to evaluate the pattern of peri-implant bone loss over 2 years and to analyze the clinical relevance of abutment angulation and CIR. A total of 200 posterior internal-connection implants placed between 2017 and 2021 were retrospectively evaluated using standardized periapical radiographs taken at baseline, 6 months, 1 year, and 2 years after loading. Bone level changes were measured mesially and distally and average per implant. Patients were categorized according to abutment angulation (<30° or ≥30°) and CIR (<1:1.5 or ≥1:1.5). The mean marginal bone loss increased during the first year (0.61 mm at 6 months to 1.08 mm at 1 year) and remained stable thereafter (1.12 mm at 2 years). Significantly greater bone loss was observed in implants restored with abutment angulation ≥ 30° (p < 0.05), whereas CIR showed no significant association at any time point (p > 0.05). No interaction effect was found between the two variables. Most peri-implant bone remodeling occurred within the first year after loading, followed by a stable phase. Abutment angulation of ≥30° was associated with increased bone loss, while CIR alone did not demonstrate clinical significance. When possible, minimizing abutment angulation may help improve long-term peri-implant bone stability. Full article

Aim: To develop clear, evidence-based, and standardized guidelines for the design, selection, and clinical use of implant abutments and prosthetic components in order to optimize the biological, mechanical, and esthetic performance of the implant supracrestal complex. Methods: A panel of 10 expert clinicians and researchers in prosthodontics participated in the Osstem Global Consensus Meeting. For the present consensus meeting, a scoping review was performed in advance and discussed among the participants. A comprehensive search of the literature was performed up to June 2025. Two reviewers (M.T. and F.G.) independently conducted screening, data extraction, and quality assessment using the Newcastle–Ottawa Scale. The evidence was synthesized and discussed by the panel of expert clinicians during the consensus meeting. After that, guidelines were developed using a 14-question questionnaire to formulate consensus-based clinical recommendations. The participants answered structured questions and discussed discrepancies to achieve a consensus. Results: The panel of expert clinicians reached a consensus on several prosthetic key points. Concave abutment profiles and emergence angles <30° promoted peri-implant tissue stability, while convex designs and wider angles increased risks of bone loss and peri-implantitis. Titanium remains the reference abutment material in posterior sites, while zirconia provides superior esthetics anteriorly, and hybrid abutments balance strength and esthetics. Conclusions: Prosthetic design and abutment material selection critically affect peri-implant tissue stability and esthetic outcomes. The evidence supports screw-retained designs, platform switching, and the “one abutment–one time” approach for predictable long-term success. Full article

This case report describes the esthetic and functional rehabilitation of a 45-year-old male patient presenting with a missing maxillary right lateral incisor (#12). Due to persistent insufficiency of alveolar ridge width following multiple augmentation procedures, implant placement was contraindicated. A minimally invasive prosthetic approach was therefore selected, consisting of a single-retainer lithium disilicate resin-bonded fixed dental prosthesis (RBFDP) combined with laminate veneers to optimize anterior esthetics. The cantilever design and adhesive protocol were selected based on biomechanical principles aimed at minimizing interfacial stresses and preserving enamel structure. The prosthesis was fabricated using a fully digital workflow, and adhesive bonding was performed following established ceramic and enamel surface conditioning protocols. The restoration fulfilled the patient’s esthetic and functional expectations, and clinical follow-up at 18 months demonstrated stable bonding, healthy peri-abutment tissues, and absence of technical or biological complications. This case highlights the role of lithium disilicate cantilever RBFDPs as a minimally invasive and clinically viable treatment option for the replacement of maxillary lateral incisors when implant therapy is contraindicated, with outcomes limited to short- to medium-term observation. Full article

Introduction: The fracturing of abutment screws is a recurrent technical complication in implant-supported prostheses that may compromise prosthetic maintenance. Although multiple retrieval approaches have been described, comparative data under controlled experimental conditions remain limited. Materials and Methods: This in vitro pilot study evaluated the retrievability of fractured abutment screws when using three commonly applied instruments: an ultrasonic scaler, a fissure bur, and a screw removal kit. Eighteen implants from a single implant system were embedded in epoxy resin, and abutment screws were fractured under clockwise monotonic torque either with (w/A) or without (w/oA) abutments (n= 3 per retrieval method). Retrieval success and procedure time were recorded. Scanning electron microscopy (SEM) was performed to qualitatively assess deformation of the implant internal hex and screw thread morphology. Results: Fracture torque values were higher in specimens fractured with abutments compared with those without abutments. Fractures induced without abutments appeared to extend deeper within the screw channel, engaging a greater number of internal threads. In this pilot study, a shorter retrieval time was observed with the screw removal kit and fissure bur compared with the ultrasonic scaler, although retrieval outcomes varied between specimens. SEM observations suggested differing patterns of internal hex deformation between the retrieval techniques. Conclusions: Within the limitations of this in vitro pilot study, different retrieval approaches demonstrated characteristic mechanical behaviors and deformation patterns in the implant internal connection. These preliminary findings provide descriptive insight into the retrievability of fractured screws and may serve as a basis for future studies with larger sample sizes and clinically relevant fracture models. Full article

This finite element study compared the effects of prosthetic superstructure material and supporting implant number on stresses in implants, multiunit abutments, and restorations, and on peri-implant bone strains under bruxism-like loading. Two posterior mandibular models representing missing left FDI 34–36 were generated: a 2-implant configuration (implants at 34 and 36) and a 3-implant configuration (implants at 34, 35, and 36), each restored with a three-unit implant-supported fixed bridge. For each configuration, three superstructure materials were simulated: cobalt–chromium (Co–Cr), polyetheretherketone (PEEK), and monolithic zirconia (MZ). Static parafunctional loads were applied as a 500 N oblique load (30° to the implant long axis; 125 N to each buccal cusp) and a 1000 N vertical load applied to the central fossae. Cortical bone generally exhibited higher strain than trabecular bone, and the maximum cortical principal strain under vertical loading averaged approximately 5800 μɛ. The highest implant von Mises stress occurred in the first molar implant of the 2-implant MZ model under oblique loading, while the maximum under vertical loading was 236 MPa (also 2-implant MZ). Prosthetic peak stresses reached 184 MPa under vertical loading (3-implant PEEK composite–veneered model) and 233 MPa under oblique loading (2-implant MZ), with a minimum of 51 MPa in the 3-implant PEEK framework under vertical loading. Overall, increasing implant number reduced the stress/strain values, and MZ showed comparatively higher stress and strain levels. Full article