Smaller radioulnar window is associated with a distal biceps tendon rupture in patients with limited forearm rotation: a 3-dimensional computed tomography comparison study of proximal impingement caused by radial tuberosity hypertrophy-a single-center case series.

BACKGROUND: It has been suggested that hypertrophy of the radial tuberosity may result in impingement leading to either a lesion of the distal biceps tendon or rotational impairment. Two previous studies on hypertrophy of the radial tuberosity had contradictory results and did not examine the distance between the radius and ulna: the radioulnar window. Therefore, this comparative cohort study aimed to investigate the radioulnar window in healthy subjects and compare it with that in subjects with either nontraumatic-onset rotational impairment of the forearm or nontraumatic-onset distal biceps tendon ruptures with rotational impairment of the forearm by use of dynamic 3-dimensional computed tomography measurements to attain a comprehensive understanding of the underlying etiology of distal biceps tendon ruptures. We hypothesized that a smaller radioulnar window would increase the risk of having a nontraumatic-onset distal biceps tendon rupture and/or rotational impairment compared with healthy individuals. METHODS: This study measured the distance between the radius and ulna at the level of the radial tuberosity using entire-forearm computed tomography scans of 15 patients at the Amphia Hospital between 2019 and 2022. Measurements of healthy subjects were compared with those of subjects who had nontraumatic-onset rotational impairment of the forearm and subjects who had a nontraumatic-onset distal biceps tendon rupture with rotational impairment of the forearm. The Wilcoxon signed rank test was used for individual comparisons, and the Mann-Whitney U test was used for group comparisons. RESULTS: A significant difference was found between the radioulnar window in the forearms of the subjects with a distal biceps tendon rupture (mean, 1.6 mm; standard deviation 0.2 mm) and the radioulnar window in the forearms of the healthy subjects (mean, 4.8 mm; standard deviation, 1.4 mm; P = .018). A trend toward smaller radioulnar windows in the rotational impairment groups was also observed, although it was not significant (P > .05). CONCLUSIONS: The radioulnar window in the forearms of the subjects with a distal biceps tendon rupture with rotational impairment was significantly smaller than that in the forearms of the healthy subjects. Therefore, patients with a smaller radioulnar window have a higher risk of rupturing the distal biceps tendon. Nontraumatic-onset rotational impairment of the forearm may also be caused by a similar mechanism. Future studies are needed to further evaluate these findings.

A novel ex vivo perfusion-based mandibular pig model for dental product testing and training.

BACKGROUND: A translational ex vivo perfusion-based mandibular pig model was developed as an alternative to animal experiments, for initial assessment of biomaterials in dental and maxillofacial surgery and training. This study aimed to assess the face and content validity of the novel perfusion-based model. METHODS: Cadaveric porcine heads were connected to an organ assist perfusion device for blood circulation and tissue oxygenation. Dental professionals and dental trainees performed a surgical procedure on the mandibula resembling a submandibular extraoral incision to create bone defects. The bone defects were filled and covered with a commercial barrier membrane. All participants completed a questionnaire using a 5-point Likert scale to assess the face and content validity of the model. Validation data between the two groups of participants were compared with Mann-Whitney U test. RESULTS: Ten dental professionals and seven trainees evaluated the model for face and content validity. Participants reported model realism, with a mean face validity score of 3.9 ± 1.0 and a content validity of 4.1 ± 0.8. No significant differences were found for overall face and content validity between experts and trainees. CONCLUSION: We established face and content validity in a novel perfusion-based mandibular surgery model. This model can be used as an alternative for animal studies evaluating new biomaterials and related dental and maxillofacial surgical procedural training.

Biomaterial-based possibilities for managing peri-implantitis.

Peri-implantitis is an inflammatory disease of hard and soft tissues around osseointegrated implants, followed by a progressive damage of alveolar bone. Oral microorganisms can adhere to all types of surfaces by the production of multiple adhesive factors. Inherent properties of materials will influence not only the number of microorganisms, but also their profile and adhesion force onto the material surface. In this perspective, strategies to reduce the adhesion of pathogenic microorganisms on dental implants and their components should be investigated in modern rehabilitation concepts in implant dentistry. To date, several metallic nanoparticle films have been developed to reduce the growth of pathogenic bacteria. However, the main drawback in these approaches is the potential toxicity and accumulative effect of the metals over time. In view of biological issues and in attempt to prevent and/or treat peri-implantitis, biomaterials as carriers of antimicrobial substances have attracted special attention for application as coatings on dental implant devices. This review will focus on biomaterial-based possibilities to prevent and/or treat peri-implantitis by describing concepts and dental implant components suitable for engagement in preventing and treating this disease. Additionally, we raise important criteria referring to the geometric parameters of dental implants and their components, which can directly affect peri-implant tissue conditions. Finally, we overview currently available biomaterial systems that can be used in the field of oral implantology.

Comparison of different surface modifications for titanium implants installed into the goat iliac crest.

OBJECTIVES: This in vivo study with implants installed in the goat iliac crest was performed to determine whether the biological and mechanical properties of the bone-to-implant interface are influenced by (i) the type of implant anchorage (i.e., mono- vs. bicortical placement), and (ii) the presence of a bioactive hydroxyapatite (HA) or composite HA/bioactive glass (BG) coatings. MATERIALS AND METHODS: A total of 96 titanium (Ti) implants w/- coatings (Ti, Ti-HA & Ti-HABG; n = 8) were mono- or bicortically placed in the iliac crest of eight goats. At installation and after 4 weeks, implant stability was determined using insertion and removal torque testing (ITQ & RTQ). The peri-implant bone response was histologically and histomorphometrically evaluated by means of bone-to-implant contact (BIC%) and bone area (BA%). RESULTS: Monocortical implants demonstrated significantly lower RTQ values in comparison to ITQ values, whereas for bicortical implant placement RTQ and ITQ were similar. Further, mean RTQ values for monocortical implants were significantly lower in comparison to bicortical implants. Histomorphometrical evaluation demonstrated higher BIC% and BA% for bicortical implants compared to monocortical implants. For bicortical implants, BA% in the inner peri-implant region (0-500 µm) was significantly higher compared to the middle (500-1000 µm) and outer (1000-1500 µm) region. Also, a significant correlation was observed for monocortical implants between RTQ and BIC% and BA%. For surface modifications, no significant differences were found in ITQ and RTQ, for neither mono- nor bicortical implants. Histomorphometrically, HABG-coated implants demonstrated significantly higher BIC% compared to GAE surfaces for both mono- and bicortical implants. Bicortical HA-coated implants revealed significant higher BA% in the inner peri-implant region (0-500 µm) in comparison to bicortical GAE implants. CONCLUSIONS: This study demonstrated that bicortical implant placement beneficially affects implant stability during the early phase of osseointegration. A significant correlation between removal torque and bone-to-implant contact and bone area for monocortical implants was observed, but not for bicortical implants. Therefore, histomorphometrical data should be interpreted with caution to predict the biomechanical implant fixation of bone implants over time. Regarding surface modifications, in the present implantation model, the addition of BG to an RF magnetron sputtered HA coating enhanced the biological behavior of the coating compared to grit-blasted/acid-etched implants.

In vivo evaluation of bioactive glass-based coatings on dental implants in a dog implantation model.

OBJECTIVES: Although titanium is commonly used as a favorable bone implant material due to its mechanical properties, its bioactive and osteoconductive capacity is relatively low. Calcium phosphate ceramics, predominantly hydroxyapatite (HA), have been frequently used for coating purposes to improve the bioactive properties. In view of the suggested osteopromotive capacity of bioactive glasses (BGs), this study aimed to evaluate the effect of BG incorporation into HA coatings on implant performance in terms of bone contact and bone area. MATERIALS AND METHODS: A total of 48 screw-type titanium implants with magnetron sputter coatings containing different ratios of HA and BG (HA, HABGLow, and HABGHigh; n = 8) were placed into the mandible of 16 Beagle dogs. After 4 and 12 weeks, their performance was evaluated histologically and histomorphometrically. Peri-implant bone area percentage (BA%) was determined in three zones (inner, 0-500 µm; middle, 500-1000 µm; and outer, 1000-1500 µm). Additionally, bone-to-implant contact (BIC%) and first bone-implant contact (1st BIC) were assessed for each sample. RESULTS: After 4 weeks, bone-to-implant contact for the HA- and HABGLow-coated groups was significantly higher (P < 0.05) than for the HABGHigh coatings. Mean values for overall BA% showed comparable values for both the HABGLow (58.3%)- and HABGHigh (56.3%)-coated groups. Data suggest that the relative BA around the HA-coated implants (67.8%) was higher, although this was only significant compared to the HABGHigh group. After 12 weeks, all three groups showed similar bone-to-implant contact and no differences in BA were found. CONCLUSIONS: The incorporation of BG into HA sputter coatings did not enhance the performance of a dental implant in implantations sites with good bone quality and quantity. On the contrary, coatings containing high concentrations of BG resulted in inferior performance during the early postimplantation healing phase.

Biofunctionalization of dental abutments by a zinc/chitosan/gelatin coating to optimize fibroblast behavior and antibacterial properties.

Tightly sealed peri-implant gingival tissue provides a barrier against oral bacterial invasion, protecting the alveolar bone and maintaining long-term implant survival. To investigate if zinc can enhance the integration between peri-implant gingival tissue and abutment surface, we herein present novel zinc/chitosan/gelatin (Zn/CS/Gel) coatings prepared using the electrophoretic deposition (EPD) technique. The effect of these coatings on human gingival fibroblasts (hGFs) was investigated by culturing these cells on top of the EPD coatings. Surface characterization demonstrated that Zn2+ were released in a sustained and pH-responsive manner. The preclinical cell culture evaluation of these coatings indicated that the zinc-containing coatings enhanced cell migration, adhesion and collagen secretion of hGFs. Moreover, the zinc-containing coatings exhibited antibacterial efficacy by inhibiting the growth of Porphyromonas gingivalis and reducing attachment of Staphylococcus aureus. Notably, zinc-free CS/Gel coatings prevented attachment of P. gingivalis as well. The coatings were also shown to be cytocompatible with epithelial cells and osteoblasts, which are other relevant cell types which surround dental implants after clinical placement. Based on our findings, it can be concluded that Zn-containing coatings hold promise to enhance the adhesion of gingival tissue to the implant surface, which may potentially contribute to the formation of a robust peri-implant soft sealing counteracting bacterial invasion.

Exploring the Prevalence of Oral Features for Early Detection of PTEN Hamartoma Tumour Syndrome.

AIMS: Patients with PTEN hamartoma tumour syndrome (PHTS) have an increased risk of developing cancer due to a pathogenic germline variant in the PTEN tumour suppressor gene. Early recognition of PHTS facilitates initiation of cancer surveillance which is highly effective in preventing the development of advanced malignancies. PHTS is rare and due to its varied phenotype, even within families, oral abnormalities may be a valuable tool in the identification of these patients at an early stage before cancer development. MATERIALS AND METHODS: Between 1997 and 2020, phenotypic characteristics were evaluated in 81 paediatric (median age: 9 years) and 86 adult (median age: 40 years) PHTS patients by one of 2 medical experts during yearly surveillance visits at a Dutch PHTS expertise centre. Oral features evaluated included gingival hypertrophy, oral papillomas, and high palate (in adults). RESULTS: Within adults, gingival hypertrophy was present in 94%, oral papillomas in 88%, and a high palate in 89%. All adult patients had at least one of these oral features, and 99% showed at least 2 oral features. Oral features were less common in paediatric patients, especially under 11 years of age. Gingival hypertrophy was observed in 44% and oral papillomas in 54% of paediatric patients. CONCLUSIONS: The presence of 2 or 3 oral features may indicate PHTS in adults or adolescents, especially if macrocephaly is present. Dental professionals are well-positioned to recognise these oral manifestations could be related to PHTS. They can initiate an overall clinical assessment of the patient by alerting the patient's medical practitioner of the findings and the possible need for genetic testing. This could significantly improve outcomes, including life expectancy, for patients and possibly for their relatives. CLINICAL RELEVANCE: Dental professionals are ideally placed to recognise oral features and initiate early assessment of PHTS which could significantly improve patient outcomes.

Long-term survival of calcium phosphate-coated dental implants: a meta-analytical approach to the clinical literature.

BACKGROUND: Calcium phosphate ceramic coatings have the potential to compensate for challenging bone conditions such as delayed or impaired bone healing and low bone quantity or density. Thus, the increasing universal prevalence of subjects with such challenging bone conditions might be paralleled by an enhanced global use of calcium phosphate ceramic-coated dental implants. However, it is speculated that the long-term clinical survival of calcium phosphate-coated dental implants might be adversely affected by coating delamination. OBJECTIVE: The aims of the current review were (1) to systematically appraise and (2) to meta-analyse long-term survival data of calcium phosphate-coated dental implants in clinical trials. MATERIALS AND METHODS: An extensive search in the electronic databases of the National Library of Medicine (http://www.ncbi.nlm.nih.gov), The Cochrane Central Register of Controlled Trials and the ISI Web of Knowledge, was carried out for articles published between January 2000 and November 2011 to identify randomized controlled clinical trials, prospective clinical trials as well as retrospective analysis of cases (RA) presenting survival data on the topic of calcium phosphate-coated dental implants. Only publications in English were considered, and the search was narrowed to studies in humans with a follow-up of at least 5 years only. Furthermore, the reference lists of related review articles and publications selected for inclusion in this review were systematically screened. The primary outcome variable was percentage annual failure rate (AFR), and the secondary outcome variable was percentage cumulative survival rate (CSR). RESULTS: The electronic search in the database of the National Library of Medicine, The Cochrane Central Register of Controlled Trials and the ISI Web of Knowledge, resulted in the identification of 385 titles. These titles were initially screened by the two independent reviewers for possible inclusion, resulting in 29 publications suitable for further consideration. Screening the abstracts led to 20 full-text articles. From these articles, 15 reports were excluded. Finally, five of these original research reports could be selected for evaluation. No additional publications were identified by manual search. Thus, a total of five articles were included for analysis. Meta-analysis revealed that neither AFRs of calcium phosphate-coated dental implants increased progressively nor that long-term CSRs for calcium phosphate-coated dental implants were inferior to survival rates of noncoated implants. CONCLUSION: We conclude that (1) published long-term survival data for calcium phosphate-coated dental implants are very limited, (2) AFRs of calcium phosphate-coated dental implants do not increase progressively, and (3) long-term CSRs for calcium phosphate-coated dental implants are comparable to survival rates of noncoated implants.

Biological response to titanium implants coated with nanocrystals calcium phosphate or type 1 collagen in a dog model.

OBJECTIVE: The current study aimed to evaluate the osteogenic potential of electrosprayed organic and non-organic surface coatings in a gap-implant model over 4 and 12 weeks of implantation into the dog mandible. MATERIAL AND METHODS: Sixteen Beagle dogs received experimental titanium implants in the mandible 3 months after removal of left premolars (P2, P3 and P4). Three types of implants were installed in each animal: non-coated implant, nano-CaP coated implant and implant with type 1 collagen coating. Both micro-CT and histomorphometry were used to evaluate peri-implant bone response after implantation periods of 4 and 12 weeks. The bone area percentage was assessed histomorphometrically in three different zones (inner: 0-300 µm; middle: 300-600 µm; and outer: 600-1000 µm) around the implant surface. Bone-bridging of the gap was also calculated for each sample. RESULTS: Four weeks after implantation, nano-CaP and collagen-coated implants showed significantly higher bone volume (BV) in the inner zone compared with non-coated implants (P < 0.05 and P < 0.01). After 12 weeks, histomorphometric analysis showed comparable amounts of BV between all experimental groups. Also, no significant difference was found in the BV, as measured using micro-CT, between the implant groups. Absolute bone ingrowth measurements were highest for collagen-coated implants, but these differences were not significant. CONCLUSION: The obtained data failed to provide a consistent favourable effect on bone formation of the collagen coating over 3 months of implantation. It is concluded that the source of the collagen as well as the limited osseous environment overshadowed a possible effect of the applied implant surface modifications. Similarly, the tested nano-apatite surface coating did not improve peri-implant bone ingrowth into a gap-implant model.

Lateral Bone Augmentation Using a Three-Dimensional-Printed Polymeric Chamber to Compare Biomaterials.

The aim of this study was to test the suitability of calcium phosphate cement mixed with poly(lactic-co-glycolic acid) (CPC-PLGA) microparticles into a ring-shaped polymeric space-maintaining device as bone graft material for lateral bone augmentation. Therefore, the bone chambers were installed on the lateral portion of the anterior region of the mandibular body of mini-pigs. Chambers were filled with either CPC-PLGA or BioOss® particles for comparison and left for 4 and 12 weeks. Histology and histomorphometry were used to obtain temporal insight in material degradation and bone formation. Results indicated that between 4 and 12 weeks of implantation, a significant degradation of the CPC-PLGA (from 75.1% to 23.1%), as well as BioOss material, occurred (from 40.6% to 14.4%). Degradation of both materials was associated with the presence of macrophage-like and osteoclast-like cells. Furthermore, a significant increase in bone formation occurred between 4 and 12 weeks for the CPC-PLGA (from 0.1% to 7.2%), as well as BioOss material (from 8.3% to 23.3%). Statistical analysis showed that bone formation had progressed significantly better using BioOss compared to CPC-PLGA (p < 0.05). In conclusion, this mini-pig study showed that CPC-PLGA does not stimulate lateral bone augmentation using a bone chamber device. Both treatments failed to achieve "clinically" meaningful alveolar ridge augmentation.