0000000000017435
AUTHOR
Peer W. Kämmerer
Retrospective analysis of survival rates and marginal bone loss on short implants in the mandible
Objectives: Short implants have become an interesting alternative to bone augmentation in dental implantology. Design of shorter implants and longer surveillance times are a current research issue. The goal of this study was to show the survival rates of short implants below 9 mm in the partly edentulous mandibular premolar and molar regions with fixed prosthetics. Marginal vertical and 2D bone loss was evaluated additionally. Different implant designs are orientationally evaluated. Material and Methods: A total of 247 dental implants with fixed prosthetics (crowns and bridges) in the premolar and molar region of the mandible were evaluated; 47 implants were 9 mm or shorter. Patient data we…
Complications in Oral Implant Placement
The placement of dental endosseous implants is a safe and reliable routine method for functional and esthetic rehabilitation of partial or total edentulism. Even so, there is an immanent potential for both short- and long-term complications in oral implant placement leading to not only minor but also major impairments of the affected patients. Most of the complications occur unexpected while others will be iatrogenic.
Immobilization of BMP‐2, BMP‐7 and alendronic acid on titanium surfaces: Adhesion, proliferation and differentiation of bone marrow‐derived stem cells
This study analyzed the influence of titanium (TiO2 ) surface modifications with two osteogenic proteins (BMP-2, BMP-7) and an anti-osteoclastic drug (alendronic acid [AA]) on sandblasted/acid-etched (SLA) and plain TiO2 (PT) on cell adhesion, proliferation and differentiation (alkaline phosphatase [AP] and osteocalcin [OC]) of bone-marrow derived stem cells (BMSCs) after 1, 3 and 7 days in-vitro. Initially, AA surfaces showed the highest cell number and surface coverage. At day 3 and 7, BMP and AA-modified surfaces exhibited a significantly enhanced cell growth. For proliferation, at days 3 and 7, an enhancement on BMP-2, BMP-7 and AA-surfaces was seen. At day 7, SLA also showed a higher p…
GDF 15 as an anti-apoptotic, diagnostic and prognostic marker in oral squamous cell carcinoma
Growth-differentiation factor 15 (GDF 15) is involved in tumor pathogenesis and its expression is increased in many types of cancers. Functional effects of GDF 15 on oncogenesis of oral squamous cell carcinoma (OSCC) remain unclear. Therefore, the aim of this study was to examine the apoptotic characteristics of GDF 15 in OSCC cell lines in vitro and to analyze serum GDF 15 concentrations as a diagnostic and prognostic tumor marker for OSCC in vivo. Caspase activity was assessed in OSCC cell lines with the Caspase-Glo 3/7 system. Serum GDF 15 concentrations from 64 patients with histopathological proven OSCC and from 30 healthy volunteers were measured using an enzyme-linked immunosorbent a…
Modification of xenogenic bone substitute materials - effects on the early healing cascadein vitro
Introduction Initial platelet activation with subsequent cytokine release at the defect site plays a crucial role in tissue integration. The aim of this study was to evaluate the influence of topographic and biomimetic collagen modifications of a xenogenic bone substitute material (BSM) on in vitro platelet activation and cytokine release. Material and Methods Three types of xenogenic BSM were used. Two BSM with different levels of granularity (large granule BSM [XBSM/L], small granule BSM [XBSM/S]) and a BSM with collagen (XBSM/C). All three samples were incubated with platelet concentrate of four healthy volunteers at room temperature for 15 min. For all groups, highly thrombogenic collag…
Associations between single-nucleotide polymorphisms of the VEGF gene and long-term prognosis of oral squamous cell carcinoma.
Department of Otorhinolaryngology, Johannes Gutenberg-University, Mainz, GermanyINTRODUCTION: Functional polymorphisms (SNPs) ofthe vascular endothelial growth factor (VEGF) are asso-ciated with the incidence of oral squamous cell carcinoma(OSCC). An impact of VEGF-SNPs on prognosis of OSCCpatients seems possible. Therefore, correlations betweenprognostic parameters of OSCC patients and five VEGF-SNPs were determined.MATERIALS AND METHODS: In a retrospective long-term study, in 113 OSCC patients that underwentcurative resections, five VEGF-SNPs ( 1154 G/A,+405 G/C, +936 C/T, 2578 C/A, and 460 C/T) wereanalyzed. Associations between SNPs and prognosis(incidence of local recurrent disease, seco…
Vertical Bone Augmentation with Simultaneous Dental Implantation Using Crestal Biomaterial Rings: A Rabbit Animal Study
Background: Ceramic biomaterial blocks like hydroxyl apatite are too brittle for simple simultaneous vertical augmentation and dental implant placement. Biological scaffolds of xenogenic or allogenic origin are known to be advantageous. Purpose: The aim of this study was the proof of principle for combined vertical bone augmentation and dental implantation with marginal cuffs made of biological scaffolds with interconnecting porous system and titanium dental implants. Materials and Methods: Cylindrical porcine biomaterial rings (processed, mineralized bone matrix) were placed in combination with titanium dental implants in the tibia model using six chinchilla bastard rabbits (n = 12 samples…
Dexrazoxane shows cytoprotective effects in zoledronic acid-treated human cells in vitro and in the rabbit tibia model in vivo
Abstract Introduction Bisphosphonates are important and effective drugs in oncology and osteoporosis therapy. They accumulate in the bone matrix becoming released and active by bone resorption. This leads to effective inhibition of tumor cells and bone degradation. A side effect of bisphosphonates similar to other drugs like denosumab is osteonecrosis of the jaws (ONJ). This problem mostly occurs after tooth extraction. We studied the cytoprotectant dexrazoxane known from anthracycline chemotherapy for cytoprotection in nitrogen-containing bisphosphonate treated cells and in the rabbit tibia model to evaluate a possible value in ONJ management. Materials & methods Human osteoblasts (HOB) P2…
Osseoconductivity of a Specific Streptavidin-Biotin-Fibronectin Surface Coating of Biotinylated Titanium Implants - A Rabbit Animal Study
Background Biofunctionalized implant surfaces may accelerate bony integration and increase long-term stability. Purpose The aim of the study was to evaluate the osseous reaction toward biomimetic titanium implants surfaces coated with quasicovalent immobilized fibronectin in an in vivo animal model. Materials and Methods A total of 84 implants (uncoated [control 1, n = 36], streptavidin–biotin coated [test 1, n = 24], streptavidin–biotin–fibronectin coated [test 2, n = 24]) were inserted 1 mm supracortically in the proximal tibia of 12 rabbits. The samples were examined after 3 and 6 weeks. Total bone-implant contact (tBIC; %), bone-implant contact in the cortical (cBIC; %) and in the spong…
Influence of class M1 glutathione S-transferase (GST Mu) polymorphism on GST M1 gene expression level and tumor size in oral squamous cell carcinoma.
Glutathione S-transferases (GST) are antioxidant enzymes and oxidative stress markers in oral carcinogenesis. They present a system of polymorphic proteins. Some variants are associated with increased sensitivity to toxic compounds, as it is known for the GSTM1-null variant allele. However, the influence of the GSTM1 allele variant genotype on GSTM1-mRNA quantity in oral squamous cell carcinoma (OSCC) and normal mucosa as well as the impact on prognosis remains unclear. The genotype for GSTM1 (mutation vs. wild type) was determined by polymerase chain reaction (PCR) using genomic DNA extracted from peripheral blood from 28 OSCC patients. From the same patients, 28 pairs of OSCC cells and no…
Re: Pontes HA, Pontes FS, Lameira AG, Salim RA, Carvalho PL, Guimarães DM, Pinto Ddos S Jr.: Report of four cases of ameloblastic fibro-odontoma in mandible and discussion of the literature about the treatment. J Craniomaxillofac Surg 40(2): e59-e63, 2012 Feb. Epub 2011 Apr 15.
Continuous Electrical Stimulation Affects Initial Growth and Proliferation of Adipose-Derived Stem Cells
The aim of the study was to establish electrical stimulation parameters in order to improve cell growth and viability of human adipose-derived stem cells (hADSC) when compared to non-stimulated cells in vitro. hADSC were exposed to continuous electrical stimulation with 1.7 V AC/20 Hz. After 24, 72 h and 7 days, cell number, cellular surface coverage and cell proliferation were assessed. In addition, cell cycle analysis was carried out after 3 and 7 days. After 24 h, no significant alterations were observed for stimulated cells. At day 3, stimulated cells showed a 4.5-fold increase in cell numbers, a 2.7-fold increase in cellular surface coverage and a significantly increased proliferation.…
Palatal steatocystoma simplex—a rare oral finding at an even rarer location
ABSTRACT Steatocystoma is a rare, benign cyst that mostly originates from a dermal sebaceous gland. It can be divided into steatocystoma multiplex—with multiple locations—and steatocystoma simplex occurring at a single site. The lesion is mostly located on the skin but can be found on other locations as well. This is the first case report of steatocystoma simplex that was found in the palate of a 37-year-old male. After resection with small safety margins and local wound dressing, no recurrence was detected during a follow-up of 1.5 years.
Customized Titanium Lattice Structure in Three-Dimensional Alveolar Defect: An Initial Case Letter
The aim of this initial case report was to provide a new protocol for the clinical application of a patient-specific titanium lattice structure (Yxoss CBR®, ReOSS, Filderstadt, Germany) for customized bone regeneration. To obtain a 3-dimensional reconstruction of a posterior mandible segment in a 61-year-old woman, a patient-specific titanium customized lattice structure was used. As graft material autogenous bone tissue mixed with xenogenic alloplastic material (Bio Oss®, Geistlich Pharma, Wolhusen, Switzerland) was obtained for reconstruction. After a healing period of 6 months, the titanium lattice structure was removed and implant placement (Camlog Screw Line, 3.8/11, Camlog, Wimsheim, …
Possible Implications for Improved Osteogenesis? The Combination of Platelet-Rich Fibrin With Different Bone Substitute Materials
Bone substitute materials (BSM) are widely used in oral regeneration, but sufficient angiogenesis is crucial for osteogenesis. The combination of BSM with autologous thrombocyte concentrations such as platelet-rich fibrin (PRF) may represent a clinical approach to overcome this limitation. This study analyzes the early influence on osteoblast (HOB) in vitro. Here, four different BSM (allogeneic, alloplastic, and two of xenogeneic origin) were combined with PRF. After the incubation with osteoblasts for 24 h, cell viability, migration, and proliferation were assessed. Next, marker of proliferation, migration, and differentiation were evaluated on gene and protein levels in comparison to the …
Single nucleotide polymorphisms of the vascular endothelial growth factor gene associated with incidence of oral squamous cell carcinoma
J Oral Pathol Med (2010) 39: 786–792 Background: Vascular endothelial growth factor (VEGF) plays an important role in promoting angiogenesis and is overexpressed in several malignancies. Polymorphisms of the VEGF gene can alter VEGF protein expression, which may be biologically significant and account for heterogeneity in disease risk and outcome. The aim of this case–control study was to evaluate potential associations between single nucleotide polymorphisms (SNP) of the VEGF gene with susceptibility of oral squamous cell carcinoma (OSCC). Patients and methods: Five VEGF SNP (−1154 G/A, +405 G/C, +936 C/T, −2578 C/A and −460 C/T) were determined in peripheral blood isolated from 80 patie…
Surgical evaluation of panoramic radiography and cone beam computed tomography for therapy planning of bisphosphonate-related osteonecrosis of the jaws
The purpose of this retrospective study was to compare the clinical significance of panoramic radiography (orthopantomography [OPTG]) and cone beam computed tomography (CBCT) for therapy planning of bisphosphonate-related osteonecrosis of the jaw (BRONJ) by surgeons.Using standardized questionnaire, eight maxillofacial surgeons evaluated intraoral photographs of the clinical situation of 14 patients with BRONJ as well as the corresponding radiographic images (OPTG, CBCT). The presence of five typical BRONJ signs (bone-remodeling, periosteal reaction, osteosclerosis, sequestra, and continuity of cortical bone) was evaluated with OPTG and CBCT. The influence of radiologic information on thera…
Local and systemic risk factors influencing the long-term success of angular stable alloplastic reconstruction plates of the mandible
Introduction: After ablative surgery of the mandible, angular stable alloplastic reconstruction plates are commonly employed. The aim of the study was a long-term evaluation of local anatomical, as looking at systemic factors influencing specific complications and the failure rate of such plates. Materials and methods: In a retrospective study covering an 11-year period, we reviewed the outcomes of angular stable plates of patients who had a segmental resection of the mandible and subsequent alloplastic reconstruction. Complications and failure rates were assessed and local (anatomical size and localization of resection) as well as systemic risk factors (age, sex, radiation therapy, smoking…
Evaluation of ultrasound transmission velocity and 3-dimensional radiology in different bone types for dental implantology: a comparative ex vivo study.
Objective To evaluate ultrasound transmission velocity (UTV) for assessment of mechanical bone quality, an ex vivo comparison of different bone types measured with UTV, 2-dimensional (2D) histomorphometry and with 3-dimensional (3D) radiology (cone-beam computerized tomography [CBCT], computerized microtomography [μCT]) was conducted. Study Design Clinical cortical, cancellous, and mixed bone (each n = 6) was measured via UTV (m/s), CBCT (white pixel/black pixel ratio [WP/BP]), μCT (bone volume/total volume [μBV/TV]), and histomorphometry (bone volume/total volume [hBV/TV]). UTV values were correlated with 2D-histomorphometry and 3D-radiologic results. Results For the cortical, cancellous, …
Early implant healing: promotion of platelet activation and cytokine release by topographical, chemical and biomimetical titanium surface modifications in vitro
Abstract Objectives: Platelet releasate has been shown to promote osteogenetic cell proliferation and differentiation. Topography and chemistry of biomaterials have high impact on platelet activation. More specifically, the bioactive cell adhesive peptide sequence Arg–Gly–Asp (RGD) triggers platelet activation mediated by the αIIbβ3 integrin receptor. Accordingly, topographical, chemical and biomimetical (immobilized RGD peptide) modifications of titanium (Ti) surfaces may enhance early platelet activation and bony healing of implants. Therefore, the aim of the study was to evaluate platelet activation with subsequent platelet-derived cytokine release by accordingly modified Ti surfaces. Ma…
The Effects of Alveolar Ridge Preservation: A Meta-Analysis
Purpose The aim of this article was to analyze the horizontal, vertical, and histological effects of alveolar ridge preservation (ARP) versus the ones of unassisted socket healing, in the format of an up-to-date review and meta-analysis. Materials and Methods An extensive electronic search in the electronic databases of the National Library of Medicine was conducted for articles published up to June 2014 to identify literature presenting data on the topic of ARP. Only randomized controlled trials, controlled clinical trials, and prospective trials were included for meta-analysis. Results After screening 903 abstracts from the electronic database, we included 64 studies in qualitative and 18…
Presurgical evaluation of bony implant sites using panoramic radiography and cone beam computed tomography—influence of medical education
The aim of this study was to compare the subjective quality rating of panoramic radiography (PAN) and CBCT in the planning of dental implant procedures by clinicians with different educational backgrounds.Radiographic images (PAN and CBCT) of 42 patients were examined as follows: the maxillary (MX) anterior region of patients, the MX posterior region of 16 patients and the mandibular (MD) posterior region of 16 patients. These sites were used for planning of dental implant insertion. Data sets were analyzed by examiners with different training backgrounds: three general practitioners (GP), three oral surgeons (OS) and three maxillofacial surgeons (MS). A standardized questionnaire in a stan…
The Influence of Hyaluronic Acid Biofunctionalization of a Bovine Bone Substitute on Osteoblast Activity In Vitro
Bovine bone substitute materials (BSMs) are used for oral bone regeneration. The objective was to analyze the influence of BSM biofunctionalization via hyaluronic acid (HA) on human osteoblasts (HOBs). BSMs with ± HA were incubated with HOBs including HOBs alone as a negative control. On days 3, 7 and 10, cell viability, migration and proliferation were analyzed by fluorescence staining, scratch wound assay and MTT assay. On days 3, 7 and 10, an increased cell viability was demonstrated for BSM+ compared with BSM− and the control (each p ≤ 0.05). The cell migration was enhanced for BSM+ compared with BSM− and the control after day 3 and day 7 (each p ≤ 0.05). At day 10, an accelerated wound…
Association of T-cell regulatory gene polymorphisms with oral squamous cell carcinoma
Costimulatory molecules have complementary effects on T-cell activation and their balance may control the development of oral cancer. The aim of this study was to determine the relevance of cytotoxic T-lymphocyte antigen 4 (CTLA-4), CD28 and inducible costimulator (ICOS) polymorphisms in oral squamous cell carcinoma (OSCC). Genotyping for CTLA-4 (-1661 A/G and +49 A/G), CD28 (0 C/G and +3160 G/T) and ICOS (+637 A/C and +1599 C/T) was performed in the 83 patients with OSCC, compared to the 40 unrelated healthy volunteers as controls. The genotype CTLA-4 -1661 was significantly different between the patient group and the control group. The allele CTLA-4 -1661 G was significantly found more fr…
Vascular endothelial growth factor polymorphisms as effect modifiers of oral squamous cell carcinoma risk: A systematic review and meta-analysis.
Smoking is one of the main risk factors for the development of oral squamous cell carcinoma (OSCC). Smoking may affect single-nucleotide polymorphism (SNP)-dependent vascular endothelial growth factor (VEGF)-induced angiogenic activity. Therefore, we systematically reviewed the published VEGF-SNP genotype data of OSCC patients and healthy individuals and performed a meta-analysis comparing the VEGF-SNP genotypes of smoking and non-smoking patients in association with OSCC incidence. Prospective and retrospective studies on the clinical comparison of OSCC patients with different VEGF-SNP genotypes were reviewed. The meta-analysis re-pooled studies of smoking and non-smoking OSCC patients wit…
Therapy and prognosis of extraoral malignant melanoma metastasizing to the jaw: case report and literature review.
t a d With approximately 75% of all skin cancer-related deaths, malignant melanoma (MM) is the most lethal among common skin cancers, mostly because of its disposition to early lymphogenic and hematogenic metastasis. If a MM is diagnosed early, the overall prognosis is excellent, but once metastasized it becomes an incurable disease with high mortality. Prognosis is dependent on parameters such as gender, anatomic location, level of invasion, thickness, type of primary tumor, ulceration, and number and status of regional lymphatic nodes. For incidence and mortalty, a decrease in young but an increase in older roups—with geographic differences—has been reported. Because of the embryologic or…
Hemoglobin, C-reactive protein and ferritin in patients with oral carcinoma and their clinical significance – A prospective clinical study
For oral squamous cell carcinoma (OSCC), biomarkers are much in need to predict prognosis and to overcome possible resistance mechanisms to adjuvant therapies. The aim of this study was to evaluate serum level of hemoglobin, C-reactive protein (CRP) and ferritin as possible liquid biopsy to predict survival, metastasis and tumor relapse of OSCC.A prospective clinical study was conducted. Overall, serum levels of hemoglobin, CRP and ferritin in 82 OSCC patients and 63 controls were preoperatively investigated.Patients with an anemia showed a significant lower survival than patients with no anemia preoperative. Patients with T3/T4 cancer had significant lower hemoglobin values (p = 0.002). CR…
Comparison of conventional twist drill protocol and piezosurgery for implant insertion: an ex vivo study on different bone types.
Objective The aim of this ex vivo study was to compare implant insertion procedures using piezosurgery and conventional drilling in different qualities of bone. Implant bed preparation time, generated heat, and primary implant stability were analyzed. Material and methods Fresh ex vivo porcine bone block samples (cancellous, mixed, and cortical bone) were obtained. The bone quality was quantified by ultrasound transmission velocity (UTV). Each bone sample received three implants of the same diameter using each of the techniques of piezosurgery and conventional twist drills. Time for preparation was taken and the temperature while performing the osteotomy was measured using infrared spectros…
Immobilisation of linear and cyclic RGD-peptides on titanium surfaces and their impact on endothelial cell adhesion and proliferation
Functional coatings on titanium vascular stents and endosseous dental implants could probably enhance endothelial cell (EC) adhesion and activity with a shortening of the wound healing time and an increase of peri-implant angiogenesis during early bone formation. Therefore, the role of the structure of linear and cyclic cell adhesive peptides Arg-Gly-Asp (l-RGD and c-RGD) on differently pre-treated titanium (Ti) surfaces (untreated, silanised vs. functionalised with l- and c-RGD peptides) on EC cell coverage and proliferation was evaluated. After 24 h and after 3 d, surface coverage of adherent cells was quantifi ed and an alamarBlue® proliferation assay was conducted. After 24 h, l-RGD mod…
Clinical efficacy of a computerised device (STA™) and a pressure syringe (VarioJect INTRA™) for intraligamentary anaesthesia.
Introduction To evaluate the impact of experience whilst using different devices for intraligamentary anaesthesia, dental students tested clinical anaesthetic efficacy of a mechanical (PDL-S) and a computer-controlled (CCLAD) application system in restorative patients. Material and methods In a prospective study, 41 Patients in need of restorative treatment in lower posterior mandible were randomised into three groups (PDL-S: teeth n = 22; CCLAD: teeth n = 20; inferior alveolar nerve block (IANB): teeth n = 20). Dental last year students conducted anaesthesia and dental treatment. Primary objectives were differences in pain during treatment [numeric rating scale (NRS)] as well as in anaesth…
Relation between bone quality values from ultrasound transmission velocity and implant stability parameters--an ex vivo study.
Aim The objective of this study was to determine the relationship between bone qualities measured by ultrasound transmission velocity (UTV) and primary implant stability parameters measured by radiofrequency analysis (RFA) and push-out test (POT) in an ex-vivo model. Materials and methods Three blocks of fresh porcine bone samples were obtained from different anatomic regions, correlating to cortical, mixed and cancellous bone. Mechanical bone qualities of these samples were measured using UTV (expressed in m/s) prior to implantation. Three similar implants (4.1 × 11 mm, AstraTech OS) were inserted into each of the procured bone blocks. The evaluation of implant-bone interface stability was…
Comparison of 4% articaine with epinephrine (1:100,000) and without epinephrine in inferior alveolar block for tooth extraction: double-blind randomized clinical trial of anesthetic efficacy
The purpose of this clinical prospective, randomized, double-blind study was to compare the anesthetic efficacy of 4% articaine with epinephrine (1:100,000) and without epinephrine in inferior alveolar nerve block anesthesia for extractions of mandibular teeth.Eighty-eight patients received intraoral inferior alveolar nerve blocks using 4% articaine with 1:100,000 epinephrine (n = 41; group 1) or without epinephrine (n = 47; group 2) for extractions of mandibular teeth. The primary objectives were differences in onset as well as in length of soft tissue anesthesia. The amount of anesthetic solution, need of a second injection, pain while injecting, pain during treatment, postoperative pain,…
Collagen membranes of dermal and pericardial origin-In vivo evolvement of vascularization over time.
Aim of the study was to compare the evolvement of vascularization over time of collagen membranes (CMs) of dermal and pericardial origin in an in vivo animal study. Twenty-eight mice underwent implantation of three commercially available CM derived from porcine dermis (homogenous structure: CM1 (Control 1) and bilayer structure: CM2 [Control 2]), from porcine pericardium (CM3; Test 1) as well as CM3 sprayed with silica-enhanced nanostructured hydroxyapatite (CM4, Test 2). After 3, 6, 9, and 12 days, intravital fluorescence microscopy was conducted for determination of capillary diameter, density, flow, and length. At Day 12, samples were examined immunohistologically for expression of fibro…
Prospective, blinded comparison of cytology and DNA-image cytometry of brush biopsies for early detection of oral malignancy
summary Objectives: Adjunctive techniques like DNA image cytometry (DNA-ICM) have been attributed to enhance the diagnostic performance of oral brush biopsies. The aim of the study was an evaluation of brush biopsies, analysed according to morphological criteria and by DNA-ICM vs. histological findings in a blinded prospective trial. Materials and methods: Eighty eight brush biopsies of 70 patients were sampled. Only clinical suspicious but not evident malignant oral lesions were included. Clinical diagnosis was leukoplakia (n = 36), lichen planus (n = 18), verruciform erythroplakia (n = 12), erythroleukoplakia (n = 9), erosion (n = 7) and induration (n = 6). Evaluation was conducted via hi…
In Vivo Modulation of Angiogenesis and Immune Response on a Collagen Matrix via Extracorporeal Shockwaves
The effective management of tissue integration and immunological responses to transplants decisively co-determines the success of soft and hard tissue reconstruction. The aim of this in vivo study was to evaluate the eligibility of extracorporeal shock wave therapy (ESWT) with respect to its ability to modulate angiogenesis and immune response to a collagen matrix (CM) for tissue engineering in the chorioallantoic membrane (CAM) assay, which is performed with fertilized chicken eggs. CM were placed on the CAM on embryonic development day (EDD) 7
A biphasic calcium phosphate coating for potential drug delivery affects early osseointegration of titanium implants.
Background Calcium phosphate (CaP) surface coatings may accelerate osseointegration and serve as a drug delivery system for mineral-binding biomolecules. In a pilot study, the impact of a commercially available, thin CaP coating on early osseous bone remodeling was compared with a modern, subtractive-treated rough surface (SLA-like) in an animal trial. Methods In 16 rabbits, 32 endosseous implants (CaP; n = 16, SLA-like; n = 16) were bilaterally inserted in the proximal tibia after randomization. After 2 and 4 weeks, bone-implant contact (BIC;%) in the cortical (cBIC) and the trabecular bone (sBIC) as well as volume of bone within the screw thread with the highest amount of new-formed bone …
Comparison of growth & function of endothelial progenitor cells cultured on deproteinized bovine bone modified with covalently bound fibronectin and bound vascular endothelial growth factor
Objectives The objective of this study was to assess and compare the growth and function of Endothelial Progenitor Cells (EPCs) cultured on covalently bonded Vascular Endothelial Growth Factor (VEGF) and covalently bonded Fibronectin (FN) coating on deproteinized bovine bone (DBB) (test samples), compared to non-modified DBB blocks (control sample). Materials and methods The test samples were prepared by plasma polymerization of allylamine onto DBB blocks. Group1 of test samples were prepared with VEGF coating (VEGF-DBB) where as the Group2 test samples were coated with FN (FN-DBB). Non-modified DBB blocks served as a Control. EPCs were isolated and cultivated from buffy coats of peripheral…
Clinical and Radiological Long-Term Outcome of a Tapered Implant System with Special Emphasis on the Influence of Augmentation Procedures
Background and Purpose: Tapered implant designs aim to improve primary stability and implant survival in soft bone. However, respective clinical long-term data are scarce. Therefore, a clinical and radiological evaluation of the long-term success of a transgingival-supracrestal inserted tapered implant system with special emphasis on the influence of augmentation procedures was conducted. Material and Methods: In a retrospective study design, all in the Department of Oral and Maxillofacial Surgery of the University Medical Centre, Mainz, Germany, between May 2002 and March 2012, placed tapered implants (Straumann TE®, Basel, Switzerland) were analyzed. In this time period, a total of one hu…
Growth differentiation factor 15 as a radiation-induced marker in oral carcinoma increasing radiation resistance.
Background Growth differentiation factor 15 (GDF15) is involved in tumor pathogenesis of oral squamous cell carcinoma (OSCC). The aim of this study was an investigation of the potential influence of GDF15 on radioresistance of OSCC cells in vitro. Methods Oral squamous cell carcinoma cell lines were irradiated with 0, 2, or 6 Gy, and GDF15 expression in the supernatant per survived cell colony was examined with ELISA. Non-irradiated and OSCC cell lines irradiated with 6 Gy were evaluated for GDF15 expression using immunofluorescent staining. For further investigation of GDF15 effects on radioresistance, a GDF15 knockdown model in a human OSCC cell line was established, and apoptotic activit…
Clinical, therapeutic and prognostic features of osteosarcoma of the jaws - experience of 36 cases.
Abstract Introduction Osteosarcoma of the jaws (OSJ) differs from osteosarcoma of other skeletal regions due to later development, a high mortality associated with the local disease, fewer incidences of metastases and its extreme rarity. In regard to clinical and pathological parameters as well as therapeutic approaches and prognosis, OSJ has not been specifically examined to date. In order to achieve a better understanding of this special malignancy, an evaluation of incidence, treatment and prognosis of patients with OSJ in our department over the past 38 years was conducted. Materials and methods A retrospective analysis of patients with OSJ between 1972 and 2010 was performed. Informati…
Vertical osteoconductivity and early bone formation of titanium-zirconium and titanium implants in a subperiosteal rabbit animal model.
Objectives The aim of this pilot study was to evaluate the vertical osteoconductive and osteointegrative dynamics around titanium–zirconium (TiZr) implants compared to titanium (Ti) implants. Materials and methods In a split-leg design, 12 TiZr-SLActive and 12 Ti-SLActive implants were inserted 3 mm above bone level in the proximal tibia of 12 rabbits. Full periosteal flaps were repositioned to cover the site. Specimens were obtained after 10, 20 and 30 days (each n = 4 per group). Histomorphometric measurements included percentage of linear bone fill (PLF; %), new marginal vertical bone height (VBH; mm) and vertical bone-to-implant contact (vBIC; %). Statistical analysis was performed with…
Self-drilling and self-tapping miniscrews for osteosynthesis fixture after LeFort I osteotomy: An ex vivo trial for primary stability and a randomized clinical study.
Abstract Background Self-drilling osteosynthesis screws (SDS) have a potential higher primary stability together with clinical advantages such as less time effort compared to self-tapping screws (STS). The aims of the study were to compare the primary stability of SDS and STS ex vivo and to analyze of the time-saving effect in vivo . Materials and methods Ex vivo , both screws were placed in porcine bone. Torque was measured for insertion and removal. Four specimens were kept in bone for histologic bone-to-implant-contact examination. In vivo , 49 patients who received orthognathic surgery in the maxilla were included in 2 centers. In a split-mouth design, the time for osteosynthesis fixati…
Activation of Human Osteoblasts via Different Bovine Bone Substitute Materials With and Without Injectable Platelet Rich Fibrin in vitro
IntroductionThe aim of the in vitro study was to compare the effect of four bovine bone substitute materials (XBSM) with and without injectable platelet-reach fibrin for viability and metabolic activity of human osteoblasts (HOB) as well as expression of alkaline phosphatase (ALP), bone morphogenetic protein 2 (BMP-2), and osteonectin (OCN).Materials and MethodsCerabone® (CB), Bio-Oss® (BO), Creos Xenogain® (CX) and MinerOss® X (MO) ± i-PRF were incubated with HOB. At day 3, 7, and 10, cell viability and metabolic activity as well as expression of ALP, OCN, and BMP-2, was examined.ResultsFor non-i-PRF groups, the highest values concerning viability were seen for CB at all time points. Pre-t…
Proinflammatory cytokines as serum biomarker in oral carcinoma-A prospective multi-biomarker approach.
BACKGROUND Inflammation and cell-mediated immunity have a key role in different stages of carcinogenesis. The aim of this prospective study was to assess serum levels of proinflammatory cytokines interleukin-6 (IL-6), interleukin-8 (IL-8), soluble interleukin-2 receptor (sIL-2R), tumor necrosis factor alpha (TNF-α), and MHC class I polypeptide-related sequence B (MICB) in patients with oral premalignant lesion (OPL), oral squamous cell carcinoma (OSCC), and healthy controls in a multi-biomarker approach as a potential diagnostic and prognostic tool for OSCC. MATERIAL AND METHODS A total of 205 patients (81 with OSCC, 75 with OPL, and 49 healthy controls) were included in this prospective st…
The effects of shock wave stimulation of mesenchymal stem cells on proliferation, migration, and differentiation in an injectable gelatin matrix for osteogenic regeneration
The treatment of a variety of defects in bony sites could benefit from mitogenic stimulation of osteoprogenitor cells, including endogenous bone marrow-derived mesenchymal stem cells (bMSCs), and from provision of such cells with a matrix permissive of their migration, proliferation, and osteogenic differentiation. That such MSC stimulation could result from treatment with noninvasive (extracorporeal) shock waves (ESWs), and the matrix delivered by injection could enable this therapeutic approach to be employed for applications in which preformed scaffolds and growth factor therapy are difficult to deploy. The objectives of the present study were to investigate focused ESWs for their effect…
Implants in free fibula flap supporting dental rehabilitation - Implant and peri-implant related outcomes of a randomized clinical trial.
Abstract Objectives The objective of this study was to assess the difference in success rates of implants when using two or four implant-supported-overdentures following segmental mandibular reconstruction with fibula free flap. Methods and designs This prospective, parallel designed, randomized clinical study was conducted with 1:1 ratio. At baseline, all participants already had segmental reconstruction of mandible with free fibula flap. The participants were randomized into two groups: Group-I received implant-supported-overdentures on two tissue-level implants and Group-II received implant-supported-overdentures on four tissue-level implants. Success rates of the implants were evaluated…
The influence of bone marrow- and synovium-derived mesenchymal stromal cells from osteoarthritis patients on regulatory T cells in co-culture
Summary There is increasing evidence that inflammation in the synovium plays a major role in the progression of osteoarthritis (OA). However, the immunogenic properties of mesenchymal stromal cells (MSCs), which are considered to regulate immunity in various diseases, remain largely unknown in OA. The purpose of this study was to determine the influence of MSCs from OA patients on regulatory T cells (Tregs) in an allogeneic co-culture model. Bone marrow (BM) and synovial membrane (SM) were harvested from hip joints of OA patients and co-cultured with lymphocytes enriched in CD4+CD25+CD127– regulatory T cells (Treg+LC) from healthy donors. Treg proportions and MSC markers were assessed by fl…
The colocalizations of pulp neural stem cells markers with dentin matrix protein-1, dentin sialoprotein and dentin phosphoprotein in human denticle (pulp stone) lining cells
Abstract Background The primary dentin, secondary dentin, and reactive tertiary dentin are formed by terminal differentiated odontoblasts, whereas atubular reparative tertiary dentin is formed by odontoblast-like cells. Odontoblast-like cells differentiate from pulpal stem cells, which express the neural stem cell markers nestin, S100β, Sox10, and P0. The denticle (pulp stone) is an unique mineralized extracellular matrix that frequently occurs in association with the neurovascular structures in the dental pulp. However, to date, the cellular origin of denticles in human dental pulp is unclear. In addition, the non-collagenous extracellular dentin matrix proteins dentin matrix protein 1 (DM…
In vivo comparison of a granular and putty form of a sintered and a non-sintered silica-enhanced hydroxyapatite bone substitute material
Improved handling characteristics of bone substitute materials may facilitate surgical handling. However, the respective modifications should not alter the biological activity. For comparison of a ...
Osseous response on linear and cyclic RGD-peptides immobilized on titanium surfaces in vitro and in vivo
Biomimetic surface modifications of titanium implants using the Arg-Gly-Asp-sequence (RGD) are promising to accelerate bone healing in cases of medical implants. Therefore, we compared the impact of linear and cyclic RGD (l- and c-RGD) covalently coupled onto titanium surfaces on the osseous response in vitro and in vivo. In vitro, osteoblasts' behaviour on different surfaces (unmodified, amino-silanized (APTES), l- and c-RGD) was analysed regarding adhesion (fluorescence microscopy), proliferation (resazurin stain) and differentiation (RT-PCR on alkaline phosphatase (AP) & osteocalcin (OC)). In vivo, osteosynthesis screws (unmodified n=8, l-RGD n=8, c-RGD n=8) were inserted into the proxim…
Influence of Different Rehydration Protocols on Biomechanical Properties of Allogeneic Cortical Bone Plates: A Combined in-vitro/in-vivo Study
Introduction: Allogeneic cortical bone plates (CP) are used for alveolar ridge augmentation. Since CP are freeze-dried and dehydrated during processing, the breaking strength (BS) and the flexibility (FX) are reduced, resulting in a relevant risk for plate fractures during insertion. The aim of this study was to evaluate the influence of rehydration time on the biomechanical properties (BS & FX) of CP in-vitro and in vivo.Material and Methods: 40 CP were randomly divided into four experimental groups. (A) untreated control (n = 10), rehydration for 10 (B), 30 (C) and 60 (D) minutes in 0.9% saline solution (n = 10 each). BS [Newton, N] and FX [mm] (force till fracture and distance of deflect…
Ten-Year Retrospective Follow-Up Study of the TiOblast™ Dental Implant
Purpose: Long-term results in the clinical outcome of different implant systems, including high patient numbers and a long follow-up time, are rare. This retrospective study evaluated the cumulative survival rate of a self-tapping, cylindrical implant system with a conical implant-abutment connection after 10 years of prosthetic loading. Materials and Methods: A total of 516 TiOblast™ implants (Astra Tech AB, Molndal, Sweden) were placed in 108 patients. The patients were treated in the Department of Oral and Maxillofacial Surgery, Johannes Gutenberg University, Mainz, Germany, between September 1994 and May 2005. The main indications for implantation were the treatment of edentulous mandib…
Submicron Scale-Structured Hydrophilic Titanium Surfaces Promote Early Osteogenic Gene Response for Cell Adhesion and Cell Differentiation
cid_339 166..175 ABSTRACT Background and Purpose: Titanium (Ti) surface roughness and surface hydrophilicity are key factors to regulate osteogenic cell responses during dental implant healing. In detail, specific integrin-mediated interactions with the extracellular environment trigger relevant osteogenic cell responses like differentiation and matrix synthesis via transcriptions factors. Aim of this study was to monitor surface-dependent osteogenic cell adhesion dynamics, proliferation, and specific osteo- genic cell differentiation over a period of 7 days. Materials and Methods: Ti disks were manufactured to present smooth pretreatment (PT) surfaces and rough sandblasted/ acid-etched (SL…
Modulation of platelet activation and initial cytokine release by alloplastic bone substitute materials.
Objectives: Platelet-derived cytokines play a crucial role in tissue regeneration. In regenerative dental medicine, bone substitute materials (BSM) are widely used. However, initial interactions of BSM and platelets are still unknown. The aim of this study was to evaluate the potential of platelet activation and subsequent initial cytokine release by different commercial alloplastic BSM. Material and methods: Eight commercial BSM of different origins and chemical compositions (tricalcium phosphate, hydroxyapatite, bioactive glass: SiO2 and mixtures) were incubated with a platelet concentrate (platelet-rich plasma, PRP) of three healthy volunteers at room temperature for 15 min. Platelet cou…
BMP-2 and bFGF release and in vitro effect on human osteoblasts after adsorption to bone grafts and biomaterials.
Objectives Combination of scaffolds and growth factors is a promising option for several clinical problems in bone biomaterials. Simplified growth factor loading by adsorption from aqueous solution is one important option for this technology. We evaluated the adsorption followed by PBS rinsing, release and biological effect of transient loading with basic fibroblast growth factor (bFGF) and bone morphogenic protein 2 (BMP-2) on fresh frozen bone, processed bone matrix, collagen, and a ceramic material with immunofluorescence, enzyme-linked immunosorbent assay (ELISA), and qRT-PCR. Materials and methods The study consisted of three in vitro experiments (immunofluorescence, ELISA, and qRT-PCR…
Influence of platelet-derived growth factor on osseous remodeling properties of a variable-thread tapered dental implant in vivo
Objectives To evaluate the effect of platelet-derived growth factor (rhPDGF-BB) on the promotion of osteogenesis around variable-thread tapered implants in an animal model. Material and methods Twenty-four variable-thread tapered implants were inserted in the tibia of 12 rabbits. Twelve sites received additional rhPDGF-BB released from a presoaked xenogenic bone block that was fixed supracrestally. Primary outcomes were bone-to-implant contact (BIC; in % ± SD) and percentage of medullary bone fill around the implants (PMF; in % ± SD) after 3 weeks (PDGF n = 6, no PDGF n = 6) and 6 weeks (PDGF n = 6, no PDGF n = 6). Results Considerable crestal and medullary bone remodeling could be found ar…
Bone Augmentation in Dental Implantology Using Press-Fit Bone Cylinders and Twin-Principle Diamond Hollow Drills: A Case Series
Background: Bone transplants are mostly prepared with cutting drills, chisels, and rasps. These techniques are difficult for unexperienced surgeons, and the implant interface is less precise due to unstandardized preparation. Cylindrical bone transplants are a known alternative. Current techniques include fixation methods with osteosynthesis screws or the dental implant. Purpose: A new bone cylinder transplant technique is presented using a twin-drill principle resulting in a customized pressfit of the transplant without fixation devices and combining this with the superior grinding properties of a diamond coating. Materials and Methods: New cylindrical diamond hollow drills are used for cu…
Hyperspectral imaging in perfusion and wound diagnostics – methods and algorithms for the determination of tissue parameters
Abstract Blood perfusion is the supply of tissue with blood, and oxygen is a key factor in the field of minor and major wound healing. Reduced perfusion of a wound bed or transplant often causes various complications. Reliable methods for an objective evaluation of perfusion status are still lacking, and insufficient perfusion may remain undiscovered, resulting in chronic processes and failing transplants. Hyperspectral imaging (HSI) represents a novel method with increasing importance for clinical practice. Therefore, methods, software and algorithms for a new HSI system are presented which can be used to observe tissue oxygenation and other parameters that are of importance in supervising…
Combination of an allogenic and a xenogenic bone substitute material with injectable platelet-rich fibrin – A comparative in vitro study
The aim of the in vitro study was a comparison of an allogenic (ABSM) and a xenogenic bone substitute material (XBSM) with and without injectable platelet-rich fibrin (ABSM-i-PRF & XBSM-i-PRF) on cell characteristics of human osteoblasts (HOB). Here, ABSM and XBSM (+ i-PRF = test; - i-PRF = control) were incubated with HOB for 3, 7 and 10 days. HOB viability, migration, proliferation and differentiation (RT-PCR on alkaline phosphatase (AP), bone morphogenetic protein 2 (BMP-2) and osteonectin (OCN)) were measured and compared between groups. At day 3, an increased viability, migration and proliferation was seen for ABSM-i-PRF. For viability and proliferation (days 7 and 10) and for mig…
Treatment concepts of horizontally deficient ridges-A retrospective study comparing narrow-diameter implants in pristine bone with standard-diameter implants in augmented bone.
OBJECTIVES To compare clinical and radiological outcomes of narrow-diameter implants (NDI) placed in pristine bone to standard-diameter implants placed in combination with horizontal bone augmentation procedures (SDI+A) for horizontally deficient alveolar ridges. MATERIAL AND METHODS For this retrospective study, the outcome of 597 NDI (∅ 3.3 mm, 272 patients), inserted in pristine bone, were compared with 180 SDI (∅ 4.1 mm, 83 patients), inserted in combination with horizontal augmentation procedures. Oral health-related quality of life was assessed in patients available for recall. RESULTS After a mean follow-up of 37.6 ± 40 months for the NDI and of 42.4 ± 49 months for the SDI+A, surviv…
Long-term bony integration and resorption kinetics of a xenogeneic bone substitute after sinus floor augmentation: histomorphometric analyses of human biopsy specimens.
In this case series, a systematic histomorphometric analysis of two human bone biopsy specimens was conducted 1 and 5 years after grafting with a xenogeneic bovine bone substitute material (BSM). While the 1-year specimen still showed extensive signs of an active desmal ossification, the specimen after 5 years mainly showed mature lamellar bone without bone turnover or remodeling. A completed bony integration without extensive resorption of the BSM particles could be detected. Altogether, a good integration in the bone with osteoconduction and a high biocompatibility was seen.
The effect of extracellular matrix proteins on the cellular response of HUVECS and HOBS after covalent immobilization onto titanium
Biomimetic surface modifications are regarded as promising approach to stimulate cellular behavior at the interface of implant materials. Aim of the study was an evaluation of the cellular response of human umbilical cord cells (HUVECS) and human osteoblasts (HOBS) on titanium covalently coated with the extracellular matrix (ECM) proteins fibrinogen, collagen, laminin, and osteopontin. For the surface modification, titanium discs were first amino-functionalized by plasma polymerization of allylamine. The ECM protein conjugation was performed using the linker molecule α, ω-bis-N-hydroxysuccinimide polyethylene glycol (Di-NHS linker). For surface characterization, infrared spectroscopy and fl…
Vertical Osteoconductive Characteristics of Titanium Implants with Calcium-Phosphate-Coated Surfaces - A Pilot Study in Rabbits
Introduction: Osteoconductive characteristics of different implant surface coatings are in the focus of current interest. The aim of the present study was to compare the vertical osteoconductivity at the implant shoulder of supracrestal inserted calcium-phosphate coated implants (SLA-CaP) with conventional sand-blasted/acid-etched (SLA) implants in a rabbit model. Materials and Methods: SLA-CaP and SLA implants were inserted bilaterally in the mandible of four rabbits in a split-mouth design. The implants were placed 2 mm supracrestal. After 3 weeks, at the left and right implant shoulder, the percentage of linear bone fill (PLF) as well as bone-implant contact (BIC-D) were determined. Resu…
Angiogenesis-related prognosis in patients with oral squamous cell carcinoma-role of the VEGF +936 C/T polymorphism.
BACKGROUND: The aim of the study was the immunohistological assessment of VEGF-single nucleotide polymorphism (SNP)-related angiogenic activity in oral squamous cell carcinoma (OSCC) in correlation with prognosis. METHODS: Fifty OSCC samples were immunostained with CD31-antibodies. Mean microvessel density (MVD) and staining intensity were determined and associated with clinicopathological/prognostic features as well as with the VEGF +936C/T SNP. RESULTS: A significant higher MVD could be seen for T3 and T4 compared with T1 and T2, N > 0 vs. N0 as well as G3–G4 vs. G1–G2 OSCCs (all: P < 0.05). A higher MVD was also associated with increased and earlier rates of local relapses, more metastas…
Evaluation of Risk Parameters in Bone Regeneration Using a Customized Titanium Mesh
PURPOSE The aim of the study was an evaluation of risk factors for an innovative bone regeneration technique using a customized titanium mesh that was tested in a clinical setting. MATERIALS AND METHODS This retrospective study included 65 patients with 70 grafting procedures of osseous defects of the jaws with a customized titanium mesh together with Advanced- and Injectable-Platelet-Rich Fibrin (A- and I-PRF), resorbable membranes, and bone grafting materials. Exposures of the meshes and grafting outcome were analyzed according to a novel classification as (a) punctual and (b) tooth width or complete exposure of the mesh (c). No exposure was stated as (d). RESULTS In 37% of cases, exposur…
A comparison of three different attachment systems for mandibular two-implant overdentures: one-year report.
Background: There is a lack of clinical studies on the self-aligning attachment system (Locator®; Zest Anchors, Inc. homepage, Escondido, CA, USA) for two-implant-retained overdentures in the edentulous mandible. Therefore, a comparison of the Locator with two traditional designs (a rotational gold matrix and a rubber O-ring type) in clinical 1-year use was conducted. MaterialsandMethods: From 2003 to 2007, 60 patients received two Osseotite® TG Standard implants (BIOMET 3i Implant Innovations, Palm Beach Gardens, FL, USA) in the intraforaminal area of the edentulous mandible. The implants were left unloaded for 3.5 months, randomized to three different attachment systems, and loaded throug…
Image cytometric DNA analysis of mucosal biopsies in patients with primary achalasia.
(P < 0.0001), and 9c- (P = 0.0001) exceeding rate with progredient DNA alterations in the respective order. CONCLUSION: The finding that DNA aneuploidy was identifi ed by image cytometry in esophageal specimens of patients with achalasia, which may be due to specifi c chromosomal alterations presenting as precancerous lesions in 27% of patients, leads us to conclude that image cytometry represents a valuable screening tool. Abstract AIM: To determine DNA aneuploidy in mucosal biopsies of achalasia patients for subsequent rapid diagnosis. METHODS: Biopsies from the middle third of the esophagus were obtained in 15 patients with achalasia. Immunohistochemical staining was carried out with mon…
Calcium Phosphate-Coated Titanium Implants in the Mandible: Limitations of the in vivo Minipig Model
<b><i>Introduction:</i></b> We aimed to compare implant osseointegration with calcium phosphate (CaP) surfaces and rough subtractive-treated sandblasted/acid etched surfaces (SA) in an in vivo minipig mandible model. <b><i>Materials and Methods:</i></b> A total of 36 cylindrical press-fit implants with two different surfaces (CaP, <i>n</i> = 18; SA, <i>n</i> = 18) were inserted bilaterally into the mandible of 9 adult female minipigs. After 2, 4, and 8 weeks, we analyzed the cortical bone-to-implant contact (cBIC; %) and area coverage of bone-to-implant contact within representative bone chambers (aBIC; %). <b><…
Inflammation in the Human Periodontium Induces Downregulation of the α1- and β1-Subunits of the sGC in Cementoclasts
Nitric oxide (NO) binds to soluble guanylyl cyclase (sGC), activates it in a reduced oxidized heme iron state, and generates cyclic Guanosine Monophosphate (cGMP), which results in vasodilatation and inhibition of osteoclast activity. In inflammation, sGC is oxidized and becomes insensitive to NO. NO- and heme-independent activation of sGC requires protein expression of the &alpha
Customised products for orbital wall reconstruction: a systematic review
Abstract The purpose of this systematic review was to critically analyze the recent literature to present the state of the art in customized reconstruction of orbital fractures. Three electronic databases and manual search approaches were used to identify relevant articles. Only studies with a controlled clinical study design were included. Primary outcome was defined as the status of recovery (complete/partial functional and esthetic disturbances). The benefit of intra-surgical navigation should be described. Secondary outcome was defined as the time of surgery, post-surgical events and hospitalization. A total of eight studies out of 552 records identified met the inclusion criteria. Post…
Extracorporeal Shock Wave Stimulates Angiogenesis and Collagen Production in Facial Soft Tissue.
Abstract Background This study investigated the efficacy of extracorporeal shock wave (ESW) application in stimulating dermal thickness, vascularity, and collagen synthesis of facial skin in a large animal model. Materials and methods The facial skin of the maxillary and mandibular areas of goats (n = 6 per group) was treated with ESWs of different intensities (0.15 and 0.45 mJ/mm2; 1000 pulses). After 4 d, histology and immunohistochemistry were used to evaluate the following: dermal thickness, total number and abundance of microvessels, amount of type 1 collagen, and α-smooth muscle actin expression. Results Dermal thickness, number and abundance of microvessels, and collagen synthesis in…
Influence of a collagen membrane and recombinant platelet-derived growth factor on vertical bone augmentation in implant-fixed deproteinized bovine bone - animal pilot study
Combinations of bone substitute block materials with membrane techniques as well as with growth factors are possible options to enhance the prognosis of vertical bone augmentation. Therefore, the aim of the pilot study was to compare the influence of a collagen membrane and a signal protein (rhPDGF-BB) on vertical bone augmentation with a stable fixed block material (deproteinized bovine bone [DBB]).In 12 rabbits, a DBB-block was implant-fixed on the tibia in a split-leg-design. Included were: DBB only (control), DBB + collagen membrane (test), DBB + rhPDGF-BB (test) and DBB + rhPDGF-BB + collagen membrane (test). 24 samples were examined after 3 (n = 12) and 6 weeks (n = 12). Calculated pa…