Soft tissue healing at titanium implants coated with type I collagen. An experimental study in dogs

Objective: To analyse the soft tissue healing at titanium implants coated with type 1 collagen. Material and methods: Six dogs were used. The mandibular pre‐molars and the three anterior maxillary pre‐molars were extracted. Three months later mucoperiosteal flaps were raised and two test and two control implants were installed (3i^® TG Osseotite^®3.75 × 10 and 2.8 mm transmucosal collar). The test implants were coated with a purified porcine type I collagen. Cover screws were placed and flaps were sutured. The sutures were removed 2 weeks later and a plaque‐control programme was initiated. Another 2 weeks later, the procedure was repeated in the contra‐lateral mandibular region. Four weeks after the second implant surgery, biopsies were obtained and prepared for histological examination. Results/Conclusion: The vertical dimensions of the epithelial and connective tissue components as well as the composition of the connective tissue portion facing the implant were similar at collagen‐coated and uncoated implants after 4 and 8 weeks of healing. It is suggested that soft tissue healing to implants coated with type I collagen was similar to that at non‐coated titanium implants and that no adverse reactions to the collagen‐coated implants occurred.     

The mucosal attachment to titanium implants with different surface characteristics: an experimental study in dogs

BACKGROUND: Findings from in vitro studies have indicated that the orientation and proliferation of cells on titanium surfaces may be influenced by the topography of the surface on which they are grown. It may be argued, therefore, that differences may occur in the mucosal attachment to titanium implants with different surface roughness. AIM: The present experiment was performed to study the composition of the soft tissue barrier that formed to implants prepared with well-defined smooth or rough surfaces. MATERIAL AND METHODS: Five beagle dogs were used. Four implants made of c.p. titanium were placed in the right edentulous mandibular premolar region. After 3 months, two different types of abutments were connected: one experimental (OA) with a dual, thermal acid-etched surface ('Osseotite'), and one regular (RA) abutment with a 'turned' surface. At the end of a 6-month period during which proper plaque control had been maintained, biopsies including the implant and the surrounding soft and hard tissues were obtained, decalcified and processed for light and electron microscopy. A confocal He-Ne laser profilometer was used to study the surface topography of the abutments. RESULTS: The attachment between the peri-implant mucosa and titanium abutments with either a turned (RA; 'smooth') or acid-etched (OA; 'rough') surface was similar from both a quantitative and a qualitative aspect. The attachment comprised a barrier epithelium and a zone of connective tissue attachment of similar dimension at RA and OA. It was further observed that the 'inner' zone of the connective tissue attachment at both types of abutment was composed of about 30-33% fibroblasts and 63-66% collagen. CONCLUSION: It was demonstrated that the soft tissue attachment that formed to implants made of c.p. titanium was not influenced by the roughness of the titanium surface.     

The influence of epigenetics in relation to oral health

The immune response is influenced by genetic and epigenetic factors, as well as disease and environmental factors. The term ‘epigenetics’ describes changes in the genome that influence the gene expression without altering the DNA sequence. In contrast to genetic changes in the DNA, epigenetic changes are reversible and are influenced by environmental factors. The aim of this study is to review the literature on epigenetic modifications with respect to oral health and inflammatory conditions in the oral cavity and to discuss the potential use of this new research field for the dental hygienists' and/or dentists' clinical work. Relevant publications were identified using the PubMed database without limits. The searches were conducted during January to March 2012 and resulted in articles published between 1912 and 2012. Key factors such as environment, diet, smoking, bacteria and inflammation were identified to be relevant to oral health. The result of this review article shows that there is a void in the research on epigenetics in relation to oral health. Identification of epigenetic modifications correlating with oral health may not only present a link between the influence of genetics and that of the environment on oral diseases but also provide new treatment models and tools for the dental professionals.     

Protein C inhibitor in human body fluids. Seminal plasma is rich in inhibitor antigen deriving from cells throughout the male reproductive system.

An assay was developed for the measurement of human protein C inhibitor antigen (PCI) in blood plasma and other biological fluids. Both native PCI, modified inhibitor, and complexes of inhibitor with activated protein C or plasma kallikrein could be measured with the assay. Inhibitor antigen concentrations were found to be very high in seminal plasma (greater than 200 mg/liter), more than 40 times the concentration of PCI found in blood plasma. The inhibitor in seminal plasma was unable to form complexes with activated protein C. Gel filtration and immunoblotting findings indicated that the inhibitor in seminal plasma is present in a high molecular mass complex or cleaved to its modified form. As PCI antigen was absent from seminal plasma of patients with dysfunctional seminal vesicles, the seminal vesicle glands would appear to be the major source of seminal plasma PCI, a conclusion supported by immunohistochemical demonstration of the presence of PCI epitopes in the secretory epithelium of the seminal vesicles. Specific PCI immunoreactivity was also shown to be present in the testes, the epididymis glands, and the prostate, suggesting the inhibitor to have a complex or multiple function in the male reproductive system. Conclusive evidence of a local synthesis of PCI in the four male sex glands was provided by Northern blot analysis of RNA from these organs.     

Vibratory stimulation compared to placebo in alleviation of pain

The placebo effect of vibratory stimulation was studied in 72 patients with chronic pain syndromes in a double-blind crossover trial using a vibrator and a "placebo unit". Pain alleviation was reported by 48% of the patients during vibratory stimulation compared with 34% for placebo treatment; statistical significance (p less than 0.005).