Search Results (341)

Background. Extensive partial edentulism alters the biological and functional balance of the stomatognathic system, requiring targeted pre-prosthetic procedures to optimize treatment outcomes. Objectives. The aim of this study was to assess the extent of improvement in the clinical–biological scores of the prosthetic field in patients with extensive edentulism, following pre-prosthetic interventions. Materials and Method. This prospective, cross-sectional study investigated 194 subjects with extensive partial edentulism. Clinical–biological scores, initially and following the pre-prosthetic phase, were recorded using a scoring system that evaluated dental and periodontal status, bone and mucosal support, occlusion, and mandibulo-cranial relationships. Statistical comparisons of clinical–biological scores were related to the type of prosthetic therapy. Statistical significance was considered at a p-value < 0.05. Results. There was an overall significant improvement in the clinical–biological scores initially (mean value 20.2) and after pre-prosthetic procedures (mean value 23.22) (p < 0.001). When treatment groups were divided, the implant-assisted prosthesis group showed the best improvement in all domains, followed by the conventional fixed-prostheses group (p < 0.01). Dental support improved significantly in those with semi-rigid composite prostheses (p = 0.014), while periodontal support was improved in both fixed- and hybrid-implant groups. Mucosal and bone support improved mostly in the fixed-implant groups (p = 0.014). Conclusions. Pre-prosthetic procedures significantly enhance the biological and functional readiness of the prosthetic field, with the degree of improvement influenced by the complexity and type of planned prosthetic rehabilitation. The findings underscore the value of individualized pre-prosthetic protocols as an essential component of prosthetic treatment planning. Full article

Background and Clinical Significance: The retreatment of failed dental implants remains a challenging clinical scenario, particularly when complicated by peri-implantitis and as sociated bone loss. Successful management requires a comprehensive and predictable approach that addresses both hard and soft tissue deficiencies. Case Presentation: This case report illustrates a fully digital, prosthetically driven workflow for the rehabilitation of a posterior mandibular site following implant failure. A 44-year-old female patient underwent removal of a failing implant and adjacent tooth due to advanced peri-implantitis and periodontitis. After healing, a digital workflow—including intraoral scanning, cone-beam computed tomography (CBCT), and virtual planning—was employed to design and fabricate a customized CAD/CAM titanium mesh for vertical guided bone regeneration. The grafting procedure utilized a composite mixture of autogenous bone and anorganic bovine bone (A-Oss). After nine months of healing, two implants with a hydrophilic surface (SOI) were placed using a fully guided surgical protocol (OneGuide system). Subsequent soft tissue grafting and final prosthetic rehabilitation with monolithic zirconia restorations resulted in stable functional and aesthetic outcomes. Conclusions: This case highlights how the integration of modern digital technologies with advanced regenerative procedures and innovative implant surfaces can enhance the predictability and long-term success of implant retreatment in compromised posterior sites. Full article

The design of custom abutments (CA) can affect the mechanical reliability of implant-supported restorations. The purpose of the study was to evaluate the influence of design parameters on the fatigue limit of CA and to compare optimized custom designs with the reference abutment (RA). A morse-tapered dental implant, an anatomical abutment, and a connector screw were digitalized using microcomputed tomography. A cone beam computed tomography scan was obtained from one of the authors to virtually place the implant-abutment assembly in the upper central incisor. Ten design parameters were selected according to the structural geometry of the RA and the implant planning. A reverse-engineered RA model was created in SOLIDWORKS and was modified considering a Taguchi orthogonal array to generate 36 CAs with ±20% dimensional variations. Finite element analysis was conducted in ABAQUS, and fatigue limits were estimated using Fe-safe. ANOVA (α = 0.1) identified the most influential parameters. Von Mises stress values ranged from 229 MPa to 302 MPa, and 94.4% of the CAs had a higher fatigue limit than the RA. Three parameters significantly affected the fatigue performance of the implant system. The design process of custom abutments includes critical design parameters that can be optimized for longer lifetimes of implant-abutment restorations. Full article

This in vitro study aims to compare the trueness of digital impressions obtained using two intraoral scanners (IOS) and one photogrammetry device for full-arch implant-supported rehabilitations. According to the Caramês Classification I, three models were produced with Straumann implants arranged in different spatial distributions: Option A with six implants and Options B and C with four implants each. The three models were scanned using a 12-megapixel scanner to create digital master casts. For each reference model, 30 digital impressions were acquired: 10 with the 3Shape Trios 3 intraoral scanner, 10 with the Medit i500 intraoral scanner, and 10 with the PIC Dental photogrammetry device. Trueness was assessed through best-fit superimpositions between the digital master casts and the corresponding virtual models. The Shapiro–Wilk test was applied to assess the normality of the data distribution, and Levene’s test was used to evaluate the homogeneity of variances. The non-parametric Kruskal–Wallis test was employed to compare group differences, with post hoc adjustments made using the Bonferroni correction. A significance threshold of p = 0.05 was adopted for all statistical tests. Statistically significant differences were observed in the root mean square values among the three devices. The Medit i500 demonstrated the highest trueness, with a median (interquartile range) deviation of 24.45 (18.18) µm, whereas the PIC Dental exhibited the lowest trueness, with a median deviation of 49.45 (9.17) µm. Among the implant distribution, the Option C showed the best trueness, with a median deviation of 19.00 (27.83). Considering the results of this in vitro study, intraoral scanners demonstrated comparable trueness, whereas the photogrammetry-based system exhibited lower trueness values. Additionally, a smaller number of implants and reduced inter-implant distances were associated with improved trueness in digital impressions for full-arch implant rehabilitation. Full article

Background: Dynamic computer-aided navigation systems are a real-time motion tracking technology widely applied in oral implantology and endodontics to enhance precision and reduce complications. However, their reliability, accuracy, and usability in dentoalveolar surgery and maxillary bone augmentation remain underinvestigated. Methods: A systematic review following PRISMA guidelines was conducted and registered on PROSPERO (CRD42024610153). PubMed, Scopus, Web of Science, and Cochrane Library databases were searched until October 2024 to retrieve English eligible studies, without restrictions on the publication year, on dynamic computer-assisted navigation systems in dentoalveolar and bone augmentation surgeries. Exclusion criteria were surgery performed without dynamic computer-assisted navigation systems; dental implant placement; endodontic surgery; and maxillo-facial surgery. The outcomes were reliability, accuracy, post-operative course, surgical duration, complications, patient- and clinician-reported usability, acceptability, and satisfaction. Included studies were qualitatively synthetized and judged using dedicated tools for the different study designs. Results: Twenty-nine studies with 214 patients were included, showing high reliability in dentoalveolar and bone augmentation surgeries comparable to or superior to freehand surgeries, higher accuracy in dentoalveolar surgery compared to maxillary bone augmentation, and reduced complication rates across all surgeries. While overall surgical duration slightly increased due to technology installation, operative time was reduced in third molar extractions. Patient-reported outcomes were poorly investigated. Clinician-reported outcomes were mixed, but difficulties in the differentiation of soft tissue from hard tissue were recorded, especially in sinus floor elevation. Conclusions: Dynamic computer-assisted navigation systems enhance accuracy and safety in dentoalveolar and bone augmentation surgery. Further studies are needed to assess the underinvestigated patient-reported outcomes and standardize protocols. Full article

Optimizing stress distribution at the bone–implant interface is critical to enhancing the long-term biomechanical performance of dental implant systems. Vertical misalignment between splinted implants can result in elevated localized stresses, increasing the risk of material degradation and peri-implant bone resorption. This study employs three-dimensional finite element analysis (FEA) to evaluate the mechanical response of peri-implant bone under oblique loading, focusing on how variations in vertical implant platform alignment influence stress transmission. Four implant configurations with different vertical placements were modeled: (A) all crestal, (B) central subcrestal with lateral crestal, (C) lateral subcrestal with central crestal, and (D) all subcrestal. A 400 N oblique load was applied at 45° simulated masticatory forces. Von Mises stress distributions were analyzed in both cortical and trabecular bone, with a physiological threshold of 100 MPa considered for cortical bone. Among the models, configuration B exhibited the highest cortical stress, exceeding the physiological threshold. In contrast, configurations with uniform vertical positioning, particularly model D, demonstrated more favorable stress dispersion and lower peak values. Stress concentrations were consistently observed at the implant–abutment interface across all configurations, identifying this area as critical for design improvements. These findings underscore the importance of precise vertical alignment in implant-supported restorations to minimize stress concentrations and improve the mechanical reliability of dental implants. The results provide valuable insights for the development of next-generation implant systems with enhanced biomechanical integration and material performance under functional loading. Full article

This study investigated the radiation attenuation characteristics of commonly used dental implant materials across an energy spectrum relevant to dental radiology. Two titanium implants were examined, with densities of 4.428 g/cm³ and 4.51 g/cm³, respectively. The first consisted of 90.39% titanium, 5.40% aluminum, and 4.21% vanadium, while the second comprised 58% titanium, 33% oxygen, 7% iron, 1% carbon, and 1% nitrogen. The third material was a zirconia implant (5Y form) composed of 94.75% zirconium dioxide, 5.00% yttrium oxide, and 0.25% aluminum oxide, exhibiting a higher density of 6.05 g/cm³. Monte Carlo simulations (MCNP6) and XCOM data were utilized to estimate photon source parameters, geometric configuration, and interactions with biological materials to calculate the half-value layer, mean free path, and tenth-value layer at varying photon energies. The results indicated that titanium alloys are well suited for low-energy imaging modalities such as CBCT and panoramic radiography due to their reduced artifact production. While zirconia implants demonstrated superior attenuation at higher energies (e.g., CT), their higher density may induce beam-hardening artifacts in low-energy systems. Future research should validate these simulation results through in vitro and clinical imaging and further explore the correlation between material-specific attenuation and CBCT image artifacts. Full article

Approximately 17,000 bears undergo bile extraction in facilities across Asia for traditional medicines despite the availability of proven alternatives. Bears are confined to cages and bile harvested from the gallbladder via needle aspiration, implanted catheters, or transabdominal fistulas. Bile-extracted bears develop numerous detrimental conditions, including abnormal repetitive behaviors, emaciation, dental disease, cholecystitis, hernias, abscesses, and neoplasia. A high prevalence of aortic dilation, commonly seen with systemic hypertension, was reported in bile-extracted bears, and aortic aneurysm rupture/dissection was the third leading cause of death in a population of 600 formerly bile-extracted bears. A high incidence of renal disease, a common cause of systemic hypertension in other species, was also identified in this population. We hypothesized that renal disease was positively correlated with lesions of systemic hypertension in bile-extracted bears. Archived medical records, imaging, and samples from 180 formerly bile-extracted bears were analyzed. Hypertensive retinopathy, left ventricular hypertrophy, and aortic dilation were used as validated correlates of systemic hypertension. The majority (76.1%) of bears exhibited at least one systemic hypertension lesion, and 62.8% had two or more lesions. Left ventricular hypertrophy was most common, followed by aortic dilation/aneurysm. Lesions of systemic hypertension were positively correlated to renal disease parameters of serum creatinine and renal histopathology. Understanding the etiology of systemic hypertension in this population is critical due to consequent comorbidities and increasing numbers of bile-extracted bears finding their way to sanctuary. Full article

Background/Objectives: Periodontal and implant therapies frequently require soft tissue augmentation for optimal outcomes. As the hard palate serves as the primary donor site, this study evaluated palatal masticatory mucosa thickness variations in a Saudi population of the Eastern Province using cone-beam computed tomography (CBCT) at a teaching dental hospital, providing site-specific data for clinical applications. Methods: A retrospective cross-sectional analysis of 215 CBCT scans from systemically healthy, non-smoking adults (>18 years) was conducted at the University Dental Hospital. Measurements were taken at 12 standardized sites (3 mm, 6 mm, and 9 mm from the cementoenamel junction) across maxillary canines, premolars, and first molars. Statistical analysis included Friedman’s test and t-tests. Results: Significant site variations were observed, with the second premolar region showing greatest thickness (3.48 ± 0.80 mm at 9 mm) and the first molar region the lowest (1.88 ± 0.63 mm at 3 mm) (p < 0.001). Mucosal thickness generally increased coronally to apically (p < 0.001). Age >35 years correlated with significantly thicker mucosa (p < 0.05), while no statistically significant gender-based differences were observed for all sites (p > 0.05). Conclusions: CBCT provides reliable, non-invasive assessment of palatal mucosa thickness. These findings offer region-specific data for consideration in periodontal and implant procedures involving soft tissue grafting. Full article

Background: Tooth loss significantly impacts the quality of life for adults. Inferior alveolar nerve (IAN) repositioning has garnered interest as a treatment for facilitating dental implant placement in the severely atrophic posterior mandible. However, there remains a need for standardization and classification of these techniques to improve outcomes. This study aims to propose a new clinical classification system for IAN repositioning procedures based on anatomical and procedural parameters. Methods: This study retrospectively analyzed preoperative radiographic records and surgical procedure documents over a 15-year period (2008–2023) for patients who underwent implant placement combined with IAN repositioning in the posterior atrophic mandible. Cases were classified into four categories according to bone availability, nerve location, and type of surgical intervention. Results: The study analyzed 142 edentulous posterior mandibles in 105 patients (77 women, 28 men; age range: 20–75). The cases were divided into four categories: Category 1 (58 patients, 78 sites), treated with one surgery; Category 2 (15 patients, 15 sites), treated in two stages; Category 3 (20 patients, 25 sites); and Category 4 (12 patients, 24 sites), with Categories 3 and 4 treated in a single surgery. Across all 132 sites, 411 dental implants were placed and restored with implant-supported fixed prostheses. Conclusions: This proposed classification provides a structured systematic framework for assessing and planning IAN repositioning procedures. It facilitates better diagnosis, treatment planning, and prediction of surgical stages in patients needing IAN repositioning for dental implant placement. Full article

The surface modification of dental implants with nanostructured films enables the development of the next generation of biomaterials that promote osseointegration. In this study, a uniform layer of titanium oxide nanotubes (TNTs) was successfully formed on a Ti-6Al-4V dental implant screw through anodic oxidation. TNTs were morphologically characterized by Scanning Electron Microscopy (SEM), obtaining dimensions of 64.88 ± 10 nm in diameter and 5.34 ± 5 µm in length. Additionally, a crystal size of 23.45 nm was determined by X-ray diffraction (XRD) analysis. The TNT layer on the dental implant screw was evaluated in an in vitro system in direct contact with human osteoblast cells (hFOB) for 24 h and 48 h, finding cell growth near to the screw threads. Further, the biocompatibility of the dental screw coated with TNTs was evaluated using a flow cytometric assay with 7-AAD, demonstrating that cell viability was not affected at 24 h and 48 h. This study opens the perspective of the study of inflammation and osseointegration induced by implants coated with TNTs. Full article

Objectives: This study aims to investigate the underlying causes of dental implant failure, focusing on implant-related complications and associated risk factors. Understanding these factors will help improve treatment planning and enhance implant success rates. Methods: A retrospective case-control study was conducted using clinical, medical, surgical, and radiographic records of patients who underwent dental implant removal due to complications. Key factors analyzed included patient-related variables (age, gender, medical conditions, periodontal disease), implant-related factors (implant site, implant system, restoration status), and procedural aspects (previous surgical interventions and reasons for implant removal). Results: The findings revealed that implant type (p = 0.004) and type of restoration (p = 0.001) significantly influenced implant survival. Gender (p = 0.001), medical conditions, smoking status (p = 0.004), and restoration status (p = 0.005) were significantly associated with specific failure mechanisms. Lack of osseointegration (36.4%) and absence of primary stability (22.4%) were the predominant causes of implant failure. Prior surgical interventions (p = 0.001) and decisions for re-implantation (p = 0.005) significantly affected implant removal frequency. Conclusions: Implant survival is influenced by multiple factors, with implant type, restoration type, and gender playing key roles in failure outcomes. Patient-specific risk assessment, particularly regarding medical conditions and smoking, meticulous surgical technique, and appropriate prosthetic planning, is vital for improving implant longevity and minimizing failure rates. Full article

Osseointegration is the direct contact between living bone and a dental implant, with supporting evidence confirming the direct connection between bone and titanium, found using an electron microscope. However, the fundamental mechanisms and interconnections between the bone and titanium are not clearly understood. At present, osteoimmunology explores the interaction between bone and immune cells not only in the medical field but also in dentistry. Immunology in bone cell formation has long been a research topic; however, interest in these effects has recently surged. Through subsequent studies, osteoimmune reaction occurs in response to dental implant insertion into the bone and this mechanism portrays more accurate tissue response compared to the traditional term osseointegration. Additionally, osseointegration is a foreign body defense mechanism to protect the implant when bone forms at the contact surface between the dental implant and the alveolar bone. The term “osteoimmunology” refers to the relationship between the immune system and bone tissues. Understanding osteoimmunologic concepts may enable the development of immunomodulatory strategies to improve, maintain, and ultimately restore osseointegration. In order for biocompatible materials such as dental implants to settle and be maintained in the body, it is necessary to understand the complex interrelationships of the bone immune environment, which will enable the development of biomaterials that are more favorable to osteoimmune environments. Therefore, this review presents previous insights into cellular and molecular interactions between bone and the immune system, specifies the roles of T-regulatory cells (Tregs) and macrophages, and demonstrates their potential for translational applications worldwide. Full article

Introduction: Hypoglossal nerve stimulation (HNS) “Inspire_© therapy” has garnered popularity among obstructive sleep apnea (OSA) patients seeking an alternative to continuous positive airway pressure (CPAP) therapy. The growth in HNS has been particularly high in older adults living with OSA. Consistent and proper use of HNS in the geriatric population faces unique age-associated barriers: a high rate of multiple chronic conditions (MCC) and polypharmacy (being on five or more drugs). Early recognition and patient-centered management of these barriers will allow older patients to obtain maximum benefits from HNS. HNS has distinct advantages in the geriatric population because it overcomes many concerns related to CPAP therapy adherence, such as mechanical limitations due to manual dexterity, maxillofacial anatomy, dental issues such as usage of dentures, allergy/otolaryngology-related disorders, and pre-existing post-traumatic stress disorder-related claustrophobia. This paper describes how we worked with older patients with OSA and their care partners to overcome these barriers so patients can continue to derive cardiovascular, neurologic, and quality of life benefits resulting from optimal OSA management. These benefits are especially important in the older population because of higher rates of comorbidities (dementia, coronary artery disease, and atrial fibrillation) exacerbated by sub-optimally treated OSA. In this article, we describe our clinical experience with elderly patients on Inspire_© therapy, with a focus on the everyday difficulties faced by these patients and the measures implemented to address and mitigate these barriers. Methods: A retrospective chart review was conducted to identify patients aged 65 and above who underwent hypoglossal nerve stimulator insertion. Experiences of older patients during and after the insertion procedure were documented and compared to a younger population of patients on HNS therapy. We specifically collected information on difficulties encountered during activation or follow-up visits and compared them between the different age groups. Using this information, we identified areas to improve treatment adherence from the patients’ perspectives. Results: We identified 43 geriatric (65 to 86 years old) patients who received the Inspire implant at a tertiary academic medical center and compared them to a younger population of 23 patients. Most common challenges noted—with a potential to impact adherence—included orofacial and lingual neuropraxia (ischemic or demyelination-induced neuropathy) at activation, cognitive dysfunction (memory problems), preexisting anxiety, and insomnia. Other difficulties that are less commonly reported but equally important to consistent and proper use of HNS included headaches, concerns of device malfunction, change in comfort levels after cardiac procedures, and general intolerance of the device. The older patient population had a statistically significant higher incidence of cognitive difficulties (30.2% vs. 4.4%) and a smaller social support system (62.8% vs. 91.3%) affecting device usage compared to the younger population. There were no statistically significant differences in the rates of other more commonly reported adverse effects such as headaches, dry mouth, and anxiety between the two age groups. Conclusion: Despite several challenges faced by geriatric patients, Inspire_© hypoglossal nerve stimulation remains a viable, alternative treatment option for OSA with improved tolerance and adherence compared to CPAP. After identifying less commonly reported barriers such as cognitive decline, sensory deficits, and decreased social support systems, minor adjustments and appropriate education on use allows older patients to correctly use and benefit from Inspire_© device therapy, with subsequent improvement in sleep and overall quality of life. Full article

Background/Objectives: Intraoral scanning, a fast-evolving technology, is increasingly integrated into actual dental workflows due to its numerous advantages. Despite its growing adoption, challenges related to the accuracy of digital impressions remain. The existing literature identifies most of the factors influencing intraoral scanning accuracy (defined by precision and trueness), but it is fragmented and lacks a unified synthesis. In response to this gap, the present study aims to consolidate and structure the current evidence on the determinant factors and, based on these findings, to develop a clinically applicable procedural guideline for dental practitioners. Methods: A comprehensive literature review identified 43 distinct factors influencing intraoral scanning. Results: These factors encompass variables such as software versions and updates, implant characteristics (e.g., position, angulation, scan body design), materials, environmental conditions (e.g., lighting), and procedural elements including scanning strategy, pattern, aids, and operator experience. Subsequently, these identified factors were systematically classified into five distinct groups based on inherent similarities and relevance within the scanning workflow: IOS—characteristics and maintenance, intraoral morphology, materials, ambient conditions, and scanning strategy. To translate these findings into a practical framework, a four-step protocol was developed, designed for straightforward application by researchers and clinicians. Conclusions: This protocol—comprising: (1) Maintenance, (2) Evaluation, (3) Establishment and Execution of Scanning Strategy, and (4) Verification—aims to guide users effectively through the intraoral scanning process, mitigate common clinical challenges, and ensure broad applicability across diverse scanner systems, irrespective of the manufacturer or model. Full article