Search Results (83)

This study evaluated how abutment screw preload affects peri-implant bone under vertical dynamic loading using an in vivo rabbit tibia model. Eight Japanese white rabbits received two implants in each tibia. After 8 weeks of healing, implants were assigned to a control group without abutment connection or to abutment-connected groups tightened to 35 Ncm or 70 Ncm. The abutment groups were further divided into loading and non-loading subgroups. In the loading groups, vertical dynamic loading (50 N, 3 Hz, 1800 cycles) was applied twice weekly for 4 weeks. Peri-implant bone responses were assessed by micro-computed tomography, histology, and histomorphometry. Under loading conditions, the 35 Ncm group showed significantly higher bone volume, bone-to-implant contact, and bone area fraction than the 70 Ncm group (p < 0.05). Histologically, the 35 Ncm group exhibited more continuous cortical bone and new bone formation, whereas the 70 Ncm group more frequently showed cortical discontinuity and enlarged marrow spaces. Within the limitations of this animal study, abutment screw preload influenced peri-implant bone adaptation under repeated loading, and the manufacturer-recommended torque of 35 Ncm was associated with more favorable bone parameters than the 70 Ncm condition. Full article

Background/Objectives: The development of high-performance biocompatible polymers such as zirconium-reinforced polyether ether ketone (BioHPP^®) has expanded the range of materials available for implant-supported prostheses, traditionally limited to metal alloys and zirconia. Due to its favorable mechanical properties and elastic modulus similar to cortical bone, BioHPP^® has been proposed as a potential alternative in implant prosthodontics. This systematic review aimed to analyze the biomechanical behavior of zirconium-reinforced PEEK and assess its advantages and limitations in implant prosthetic applications. Methods: A systematic review was conducted in accordance with PRISMA 2020 guidelines, including studies published between 2011 and 2025 that evaluated the performance of BioHPP in implant prosthetic applications. Results: The search strategy identified 34 studies that met the inclusion criteria. The included studies evaluated mechanical properties such as fracture resistance, elastic modulus, stress distribution, and peri-implant tissue response. Zirconium-reinforced PEEK demonstrated fracture resistance values reaching up to 1623.31 N and an elastic modulus of approximately 4 GPa, comparable to cortical bone. Several studies also reported favorable stress distribution patterns and reduced mechanical complications when compared with conventional metallic materials. Conclusions: Zirconium-reinforced PEEK exhibits promising biomechanical characteristics for use in implant-supported prostheses, particularly due to its fracture resistance and bone-like elastic modulus. However, the available evidence is predominantly based on in vitro and finite element studies. Long-term clinical trials are required to confirm its clinical performance and establish definitive recommendations for routine use. Full article

Background: Rehabilitation of edentulous mandibles in a post-oncologic setting remains a major clinical challenge. In such situations, placement of conventional endosseous implants may be compromised by severe bone deficiency, a history of peri-implant infection, and constraints related to reconstructive soft tissues. Customized titanium subperiosteal implants, made possible by three-dimensional imaging, computer-aided design, and additive manufacturing, represent a potential alternative when conventional options are unfavorable. This case report describes a full-arch fixed rehabilitation of an edentulous mandible in a patient previously treated for squamous cell carcinoma of the floor of the mouth. Methods: A patient-specific titanium additively manufactured subperiosteal jaw implant (AMSJI) made of biocompatible titanium was designed using a digital planning workflow. Implant placement was performed in a single surgical session under general anesthesia, with fixation using osteosynthesis screws. A screw-retained full-arch provisional prosthesis was delivered intraoperatively, allowing immediate loading with adjustments aimed at avoiding compression of the healing soft tissues. Results: The patient achieved satisfactory functional and esthetic rehabilitation. Postoperative follow-up showed overall favorable mucosal tolerance; an early, limited peri-abutment mucosal dehiscence was observed and managed with suturing under local anesthesia, without compromising implant stability. Conclusions: This case highlights the clinical interest of patient-specific titanium subperiosteal implants as a fixed rehabilitation option in post-oncologic patients with major osseous and mucosal constraints and a history of reconstructive procedures. The combination of accurate digital planning and custom-made manufacturing may avoid the need for extensive bone grafting. However, these findings should be interpreted with caution due to the short-term follow-up and the inherent limitations of a single-case report, which limit the level of evidence and generalizability. 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/Objective: To outline strategies for the safe clinical use of orthodontic temporary anchorage devices (TADs) by analyzing papers that examine associated risks, complications, and approaches for their prevention and resolution. Methods: The research protocol used PubMed, Medline, and Scopus up to May 2024, focusing on controlled and randomized clinical trials aligned with the review objective. Fourteen studies were included; bias risk was assessed, key data extracted, and a descriptive analysis performed. Study quality and evidence strength were also evaluated. Results: TADs optimize anchorage control without relying on patient compliance. However, they carry risks and complications. TAD contact with the periodontal ligament or root without pulp involvement requires removal for spontaneous healing. If pulp is involved, the TAD should be removed and endodontic therapy performed. If anatomical structures are violated, TAD should be removed. If transient, spontaneous recovery occurs, but sometimes pharmacological treatment may be needed. A 2 mm gap between the TAD and surrounding structures can prevent damage. In the maxillary sinus, a less than 2 mm perforation of the Schneiderian membrane recovers spontaneously; wider perforations require TAD removal. Good oral hygiene and TAD abutments prevent soft tissue inflammation, which resolves with 0.2% chlorhexidine for 14 days. Unwanted forces can cause TAD fractures, requiring removal. Minor TAD mobility due to loss of primary stability can be maintained; significant instability requires repositioning. Conclusions: The use of TADs requires meticulous planning, radiological guidance, and monitoring to minimize risks and manage complications. With proper care, TADs improve orthodontic outcomes and patient satisfaction. Full article

Introduction: This study highlights the importance of maintaining dental implants, particularly in the context of peri-implantitis. It emphasizes the need for dental hygienists to choose appropriate instruments that will not damage implant surfaces while effectively cleaning them. Materials and Methods: The research involved in vitro tests using 4 ultrasonic inserts for peri-implant mechanical instrumentation on one machined and one etched healing abutment, with a focus on how these instruments affect surface roughness. For each insert, four surface roughness measurements were recorded on each abutment. The data were then analyzed in two separate designs, one for the machined abutments and one for the etched abutments. The significance of the factors was determined by analyzing them using an ANOVA test. Results: The study found significant effects of surface treatment and instrument type on surface roughness parameters. Instrumentation tended to alter the roughness of machined surfaces more than etched ones, with notable differences in performance among the various inserts. Discussion: The results suggest that surface treatment has a more substantial impact on roughness than the choice of instrument. Future studies are encouraged to explore other parameters related to bacterial biofilm retention and the potential release of material from non-metallic inserts. Conclusions: Key findings include that surface treatment significantly influences surface roughness and that specific instruments can either increase or decrease roughness based on the type of surface. Full article

Background/Objectives: Immediate implant placement in the esthetic zone can shorten treatment time but maintaining peri-implant soft tissue stability is challenging. Conventional multi-stage workflows require multiple visits and may disturb peri-implant tissues. Placing a definitive one-time abutment at surgery can preserve soft tissue contours by avoiding multiple abutment changes. This case report introduces a digital one-stage approach delivering a definitive zirconia crown with delayed occlusal veneering at surgery to streamline treatment and preserve tissue stability. Methods: A 60-year-old male with a failing maxillary canine underwent immediate implant placement using guided surgery. A customized healing abutment preserved the emergence profile for the definitive restoration. A zirconia crown with an occlusal cut-back was fabricated and delivered at surgery on the one-time abutment without occlusal contact. After 12 weeks, a ceramic overlay was bonded extraorally to the crown to restore the occlusal surface. Results: At 2-year follow-up, the implant exhibited stable bone and healthy peri-implant soft tissues, with no complications. The one-time approach preserved tissue contours by eliminating provisional stages, and delayed occlusal veneering provided excellent esthetic integration. The patient was satisfied with the immediate result and fewer visits. This one-stage approach required fewer interventions than conventional provisional workflows. Conclusions: Immediate implant placement with a one-time abutment and delayed occlusal loading preserved peri-implant tissue architecture and achieved excellent functional and esthetic outcomes at 2 years. This one-stage workflow is a tissue-preserving alternative to multi-stage protocols; further studies are needed to confirm its long-term efficacy. Full article

Background: Single implants yield predictable survival and success using various treatment protocols. Innovations in design and surface texture improved survival and ensured crestal bone stability, crucial to avoiding biological complications. This study focuses on survival and peri-implant crestal bone remodeling during healing and function of single hybrid-surface implants (Machine Surface Coronal, MSc, Southern Implants Pty Ltd., Irene, South Africa), featuring a minimally rough coronal region and moderately rough body. The specific aims were firstly to compare the clinical outcome between 3 surgical protocols and secondly to assess whether the outcome is affected by macroscopic implant design. Methods: Clinical records of 120 consecutively placed single MSc-implants in private practice were scrutinized after 12–62 months in function. Implants were placed using one of three surgical protocols as selected by the surgeon based on clinical judgment and treatment indication: flap-healed surgery with healing abutment (HA), flapless surgery with HA, or immediate implant placement (IIP) with HA. Six different implant types, albeit with the same MSc-surface feature, were utilized, based on individual clinical indications. Radiographical crestal bone level changes over time were analyzed and effect of implant design, gender, smoking status and surgical protocol was explored. Results: 101 implants was available for analysis. Six implants failed prior to loading (5%); 30% in smokers versus 3.3% in non-smokers. Initial bone remodeling, due to biologic width formation, was 0.762 mm (SD 0.940) at time of loading and 0.933 mm (SD 1.057) after 2 years (p = 0.07). Steady state bone levels at final recall (12–62 months; mean 24) were irrespective of implant type (p = 0.51), surgical protocol (p = 0.10), gender (p = 0.557) or smoking habit (p = 0.27). 54% of the implants showed bone gain between loading and final, whereas only 3% had bone loss above 3 mm. Conclusions: Under daily clinical conditions, MSc-hybrid implants yield predictable clinical outcomes in line with contemporary implant systems, irrespective of implant length and diameter. A 5.9% early failure rate was found irrespective of smoking status, with no late failures. Failure rate dropped to 3.3% when smokers were excluded. Crestal bone remodeling at the time of loading, mimicking biologic width formation, as well as bone level changes over time, is indicative of a healthy peri-implant steady state irrespective of the surgical protocol. Full article

Background: Dental implants are widely used to replace missing teeth, particularly in aesthetically sensitive areas. The implant’s macrogeometry is crucial for ensuring primary stability and successful osseointegration. Internal conical connections and reactive surfaces on implants have shown positive outcomes in tissue and bone stability. In response, a hybrid conical dental implant was designed to address a variety of clinical scenarios. Materials and Methods: This pilot study evaluated the performance of the hybrid conical implant using histological and micro-CT analysis in a preclinical model with immediate loading. Five implants were placed in a mongrel dog, and histomorphometric and micro-CT assessments were performed after 60 days of healing. Results: Analysis showed a high degree of osseointegration, with BIC at 61.56% and BT/TV at 77%. Micro-CT confirmed these findings, with nBIC at 82.20%. Vertical measurements indicated stable crestal bone. Peri-implant tissue displayed organized supracrestal connective tissue, without signs of inflammation or bone saucerization. Polarized light microscopy revealed collagen fibers in perpendicular and oblique orientations around the abutment, suggesting mechanical integration and biological sealing despite the absence of a prosthetic crown. Conclusions: Within the limitations of this exploratory study with one animal study, the hybrid conical implant showed favorable biological and structural responses under immediate loading. These preliminary findings provide useful insights for the refinement of implant design, although further investigations in larger preclinical and clinical studies are required before clinical applicability can be confirmed. Full article

Background: The implant–abutment interface has been thoroughly examined due to its impact on the success of implant healing and longevity. Removing the abutment is advantageous, but it changes the biomechanics of the implant fixture and restoration. This in vitro three-dimensional finite element analytical (FEA) study aims to evaluate the distribution of von Mises stress (VMS) in abutment-free and three additional implant abutment connections composed of various titanium alloys. Materials and methods: A three-dimensional implant-supported single-crown prosthesis model was digitally generated on the mandibular section using a combination of microcomputed tomography imaging (microCT), a computer-assisted designing (CAD) program (SolidWorks), Analysis of Systems (ANSYS), and a 3D digital scan (Visual Computing Lab). Four digital models [A (BioHorizons), B (Straumann AG), C abutment-free (Matrix), and D (TRI)] representing three different functional biomaterials [wrought Ti-6Al-4Va ELI, Roxolid (85% Ti, 15% Zr), and Ti-6Al-4V ELI] were subjected to simulated static/cyclic static loading in axial/oblique directions after being restored with highly translucent monolithic zirconia restoration. The stresses generated on the implant fixture, abutment, crown, screw, cortical, and cancellous bones were measured. Results: The highest VMSs were generated by the abutment-free (Model C, Matrix) implant system on the implant fixture [static (32.36 Mpa), cyclic static (83.34 Mpa)], screw [static (16.85 Mpa), cyclic static (30.33 Mpa), oblique (57.46 Mpa)], and cortical bone [static (26.55), cyclic static (108.99 Mpa), oblique (47.8 Mpa)]. The lowest VMSs in the implant fixture, abutment, screw, and crown were associated with the binary alloy Roxolid [83–87% Ti and 13–17% Zr]. Conclusions: Abutment-free implant systems generate twice the stress on cortical bone than other abutment implant systems while producing the highest stresses on the fixture and screw, therefore demanding further clinical investigations. Roxolid, a binary alloy of titanium and zirconia, showed the least overall stresses in different loadings and directions. Full article

Background/Objectives: The aim of the study was to investigate the risk factors related to early implant failures in patients treated in a private implant clinic. Methods: The study was retrospectively conducted on 392 patients (mean age = 51.2 ± 15.4 years, 48.9% female and 51.1% male) who received 930 dental implants within the period from 2000 to 2020. Included patients had received at least one implant. Patients were excluded in case of incomplete dental records that did not contain the necessary information, including personal information (patient’s name, age, gender, history and current condition of systemic diseases) and treatment protocol record. No patients were excluded on the basis of systemic disease if it did not contraindicate dental implant surgery. Patient-related variables (age, gender, smoking, history of periodontitis, accompanying disease), surgical-related variables (surgical technique, bone augmentation, lateral sinus lift, internal sinus lift, immediate implant placement after tooth extraction, immediate mucosal grafting, insertion torque,) and implant-related variables (implant design, implant level, implant surface, site of implant placement, implants diameter, length and implants brand name) were recorded. Results: GEE analysis results showed that the implant-based failure rate before or at the abutment connection stage was 5.8%. Seven factors were identified associated with early implant failures: male gender, smoking, history of radiotherapy and chemotherapy, maxilla implant placement, non-submerged healing method, implant design and implant brand. Conclusions: In light of the results obtained, both patient-related variables (gender, smoking, history of radiotherapy and chemotherapy) and variables related to the type of implant, its position and the surgical technique used (maxilla implant placement, non-submerged healing method, implant design and implant brands) were found to be statistically correlated with early failures in this study. Full article

Objectives: The presence of gingival buccal recession is a frequent problem especially in the canine area. The cortical buccal bone may be absent in presence of health normal lingual/palatal bone and of other periodontal pockets. The present case report describes a minimally invasive approach in a 76-year-old patient with previously endodontically treated lower canine affected by root fracture and by a serious chronic buccal recession. Methods: The tooth was characterized by a deep vestibular bone defect, lack of buccal bone and acute periapical lesion. After extraction, Maryland bridge was positioned on the edentulous area. A two-piece convergent neck transmucosal implant was inserted with a flapless approach after 6 months. Maryland bridge was left in place for additional 3 months. After this time, digital impressions were taken, and a customized abutment was positioned. A provisional crown was designed according to Biologically Oriented Preparation Technique (BOPT) concept and maintained for 6 months. A zirconia definitive crown was digitally designed and cemented with a polycarboxylate-based cement. The Pink Esthetic Score (PES) was used as an index to assess peri-implant soft tissue stability over time (preoperatively, at 9 months, at 12 months and 72 months). Results: The patient was followed for 6 years under a conventional hygienic recall program. No complications occurred, and the PES improved from 4 preoperatively to 8 at 9 months, 10 at 12 months and 13 at 72 months. Conclusions: The use of Maryland bridge prevented occlusal trauma on healing tissues and appeared to support bone and soft tissue healing for transmucosal implant placement. A stable aesthetic rehabilitation was achieved up to 6 years. Full article

Background/Objectives: The aim of the present study is to evaluate the influence of the healing abutment height on secondary implant stability measured by resonance frequency analysis. In this prospective observational clinical study of 30 implants, the secondary stability of the implant was measured via resonance frequency analysis of the abutment during the osseointegration process. Methods: Two groups were compared: a <4 group (n = 15), with a space between the healing abutment and the antagonist of <4 mm, and a ≥4 group (n = 15), with a space of ≥4 mm. Results: Statistically significant differences (p < 0.05) in the implant stability values obtained at surgery (T0) and at the eighth week of osseointegration (T8) were observed between the two groups, with higher values for the <4 group. Pearson’s correlation analysis revealed a trend towards a significant relationship with the mean force (−0.6546) and a linear inverse relationship, so that by decreasing the distance between the abutment and the contact with the antagonist, the secondary implant stability values increased. A comparison of the mesial and distal peri-implant marginal bone levels at T0 and T8 did not reveal statistically significant differences (p > 0.05). A greater healing abutment height, placing it closer to the antagonist, increases and accelerates secondary stability, as measured by resonance frequency analysis. Conclusions: The results of the study support the recommendation of using high healing abutments, placing the abutment close to the opposing occlusal plane, according to biomechanical criteria. Full article

Objectives: This study aimed to evaluate the effects of different titanium (Ti) anodized surfaces on soft tissue healing around dental implant abutments. Methods: Discs of machined (MC), pink anodized (PA) and yellow anodized (YA) surfaces were morphologically characterized and evaluated in vitro. Cell adhesion and collagen synthesis by human gingival fibroblasts (hGFs) were assessed to evaluate the regenerative potential of the surfaces under study. Their inflammatory potential was evaluated in THP-1 cell cultures by measuring cytokine secretion, and their proteomic adsorption patterns were characterized using nano-liquid chromatography mass spectrometry (nLC-MS/MS). Statistical significance was considered at 5%. In relation to proteomics, statistical differences were evaluated using the Student t-test with the Perseus application. Results: The anodization process resulted in a reduction in the surface roughness parameter (Ra) relative to the machined titanium (p < 0.05). No differences in hGF adhesion were found between the surfaces after one day. PA induced increased hGF collagen synthesis after 7 days (p < 0.05). The secretion of TNF-α was lower for anodized surfaces than for MC, and its concentration was lower for PA than for YA (p < 0.05). In turn, TGF-β was higher for PA and YA versus MC after one and three days of culture. A total of 176 distinct proteins were identified and 26 showed differences in adhesion between the anodized surfaces and MC. These differential proteins were related to coagulation, lipid metabolism, transport activity, plasminogen activation and a reduction in the immune response. Conclusions: Anodized Ti surfaces showed promising anti-inflammatory and regenerative potential for use in dental implant abutments. Anodization reduced surface roughness, increased collagen synthesis and lowered TNF-α secretion while increasing TGF-β levels compared to machined surfaces. Identified proteins related to coagulation and lipid metabolism supported these findings. Clinical relevance: Anodized surfaces could offer improved short-term peri-implant soft tissue healing over machined surfaces. The analysis of abutment surface, instead of implant surface, is a new approach that can provide valuable information. Full article

Background/Objectives: The essential trace element zinc (Zn) has a pivotal role in wound healing and can show antibacterial activity, but its application in oral implant materials is underexplored. Customized healing abutments can modulate the peri-implant tissue health when appropriate bioactive materials promoting mucosal healing are used. The present study investigated a novel Zn-containing polymer for its potential in soft-tissue engineering applications. Methods: Four traditional materials—titanium, glass ionomer, a composite, and the novel Zn-containing polymer—were tested in vitro for bacterial growth using a multispecies oral bacterial model compared to hydroxyapatite. The biocompatibility of the materials was also evaluated by evaluating the adhesion, proliferation, and cytotoxicity of human oral keratinocytes (HOK-18A) onto these materials, compared to tissue culture plastic. Results: The Zn-containing polymer exhibited a significantly lower biofilm formation compared to conventional materials as it was composed of less pathogenic bacteria. The Zn-containing material also demonstrated a superior biocompatibility towards HOK-18A, approximating the adhesion and proliferation of the keratinocytes to optimal tissue culture conditions. Moreover, these properties did not seem to degrade and were maintained over a period of 31 days. The cytotoxicity assessment revealed no significant reduction in metabolic activity for any material. Conclusions: This study highlights the potential of the novel Zn-containing polymer in soft-tissue engineering, owing to its antimicrobial and biocompatible assets. These properties, combined with the ease of chairside modeling, position the material as a promising alternative for creating customized healing abutments. Further research is needed to explore its mechanism of wound healing modulation and its clinical performance. Full article