Novak Stamatovic

Proinflammatory cytokines (IL-1β and TNF-α) and chemokines (IL-8 and MIP-1α) as markers of peri-implant tissue condition

Analysis of peri-implant crevicular fluid (PICF) offers a non-invasive means of studying the host response in peri-implant disease and may provide an early indication of patients at risk for active disease. This study examined the PICF levels of interleukin-1beta (IL-1beta), tumour necrosis factor alpha (TNF-alpha), interleukin-8 (IL-8) and macrophage inflammatory protein-1alpha (MIP-1alpha) in patients with non-manifesting inflammation, early and late stages of mucositis. The study group comprised 90 adult healthy volunteers with endosseal titanium implants inserted. Samples were taken from peri-implant sulcus using a filter paper technique. Implant tissues were categorized clinically as healthy, early mucositis or advanced mucositis. Clinical manifestations were determined by: gingival index and bleeding on probing, plaque index and radiographic analyses. Cytokine concentrations were assesed using commercially available enzyme-linked immunosorbent assay kits. Patients from the control group (healthy patients) have significantly lower concentrations of IL-1beta, TNF-alpha, IL-8 and MIP-1alpha in PICF compared with both groups with mucositis. Positive correlation was noted in the control group between IL-1beta and TNF-alpha and between MIP-1alpha and IL-8 in the group with early mucositis. The results suggest that cytokines could be prognostic markers of implant failure.

CD14 and TNFα single nucleotide polymorphisms are candidates for genetic biomarkers of peri-implantitis

ObjectivesThis study aims to investigate whether CD14-159 C/T and TNFα -308 A/G single nucleotide polymorphisms are associated with peri-implantitis and to evaluate their effects on bone resorption by correlating with local levels of receptor activator nuclear factor kappa-B ligand (RANKL) and osteoprotegerin (OPG).Material and methodsStudy population included 369 Southeastern Europe Caucasians (180 with peri-implantitis and 189 with healthy peri-implant tissues). Genotyping was performed using polymerase chain reaction from the periphery blood samples, while RANKL and OPG were evaluated in peri-implant crevicular fluid specimens using enzyme-linked immunosorbent assay.ResultsAnalysis of CD14-159 C/T polymorphism showed that genotype of CC nucleic acid combination was associated with peri-implantitis demonstrating a fivefold increased risk in these carriers. Furthermore, for TNFα -308 A/G polymorphisms, it was evidenced that AG genotype was associated with peri-implantitis and a fivefold increased risk in these carriers. Peri-implantitis patients with CC genotype at CD14-159 exhibited significantly higher concentrations of RANKL and relative ratio RANKL/OPG when compared to patients with CT genotype, while concentration of biomarkers between different genotypes at TNFα -308 remained insignificant.ConclusionWithin the limitations of the study, we can conclude that CD14-159 C/T and TNFα -308 A/G polymorphisms are associated with peri-implantitis and may present biomarkers for peri-implantitis.Clinical relevanceInvestigated genetic markers might serve as precious parameters in clinical practice in course of treatment planning and prognosis, since preventive and treatment approach could be positively shifted and adjusted depending on present genotype.

[Local application of concentrated trombocytes and the level of osseointegration of dental titanium implants: a histomorphometrical analysis].

BACKGROUND/AIM In order to achieve better, and, thus an increased bone-implant interface, growth factors have been used over the past few years. All growth factors considered have fundamental role in the growth and development of cells and tissues. Concentrated trombocytes from platelet-rich plasma (CT-PRP) are fraction of the blood. Thrombocytes contain a number of growth factors namely PDGF, TGF-beta, IGF, VEGF and many others, which contribute to the achievement of the increased bone-implant interface, the increased stability of implants and the faster functional loading of implants. The aim of this study was to establish the effect of CT-PRP on bone-implant interface. METHODS This experimental study included six dogs in which 24 BCT implants were inserted (4 implants per dog). On the left side of the lower jaw 2 implants were placed with CT-PRP, while on the right side the implants were placed without CT-PRP. The animals were sacrificed after 42, 70, and 98 days. The specimens were examined histomorphometrically, and analyzed 42, 70 and 98 days after the implant insertion. The contacts bone to implant in 16 zones for each analyzed implant were measured according to the established protocol. RESULTS Results obtained with histomorphometrical analysis imply the increased bone-to-implant contact by use CT-PRP. The difference of the bone-to-implant contacts between these two groups of inserted implants has been particularly pronounced at six weeks after the implant insertion. CONCLUSION According to the obtained results in the measurement of the level of osseointegration of the inserted implants, it should be advisable to use the CT-PRP method because it provides the higher level of osseointegration.

Implant Insertion Methods and Periimplant Tissues – Experimental Study

The replacement of missing teeth with dental implants has become predictable treatment modality over the past several decades. The function of dental implants depends on the process of osseointegration, defined by Branemark (Branemark, 1985, as cited in Abrahamsson & Cardaropoli, 2006) as „direct structural and functional connection between living ordered bone and the surface of load carrying implant“. The process through which osseointegration is achieved depends on several factors, such as biocompatibility of the metal used as well as the design and surface characteristics of the implant, the condition of the implant socket, the surgical technique used and the loading conditions applied (Abrahamsson & Cardaropoli, 2006). Endosteal implants are available in various designs, forms and materials. The earliest implant designs were one-component devices, i.e. implant body and implant abutment were connected in a single unit. Those implants could only be inserted in one-stage surgical method and are collectively referred to as “one-stage” or non-submerged implant systems. When inserted, implants penetrate through the oral mucosa into the oral cavity thus risking the possible contamination and/or early loading that could result in implant failure. Within the past five decades numerous types of implant designs have evolved. Almost all of them have a common characteristic: they consist of two parts – the implant body and the implant abutment or transmucosal part. The first part (implant body) is placed into the bone socket and covered with mucoperiosteal flap. The second part (implant abutment) is connected to the implant after a period of healing in the secondary surgical procedure. These designs are recommended for so called “two-stage” or submerge surgical approach, and the components of the soft tissue cover, epithelial and subepithelial tissue, act as a barrier between the internal (bone tissue) and external (oral cavity) environment. The studies on both surgical methods have been well documented (Adell et al., 1990, as cited in Heydenrijk et al., 2002; Lindquist et al., 1996; Ericsson et al., 1996; Buser et al., 1996; Levy et al., 1996; Bragger et al., 1998; Abrahamsson et al., 1999; Hermann et al., 2001; Lindquist et al., Heydenrijk et al., 2002). On the basis of early research in dogs, Branemark and his coworkers introduced submerged implant placement believing it was one of the key prerequisites for osseointegration (Weber & Cochran, 1998). Namely, implants were placed under cover of the oral mucosa for a healing period of 3-6 months and after that period a second surgical procedure was

[Mobility of B.C.T. dental implants inserted by one- and two-phase surgical method--an experimental study].

BACKGROUND/AIM Achievement of the osseointegration of dental implants is of crucial importance for their long-term survival. One of the factors that influence the osseointegration is a surgical method of implantation. The outcome of osseointegration can be evaluated on the basis of implant mobility in bone. The aim of this study was to investigate and compare the mobility of B.C.T. dental titanium implants inserted to experimental animals using an one- and two-phase method. METHODS The investigation was performed using a split-mouth design on nine dogs, male german shephards, average age of 3.5 years and average weight of 32 kg. Extractions of the third and fourth lower premolars were performed under intravenous (i.v.) anaesthesia with 5% ketamine chloride. Eight weeks after the extractions, the implants, diameter of 4.5 mm each, with four threads 13.7 mm long, were inserted. Eighteen implants were inserted one side of the jaw using a one-phase method, and another 18 implants were inserted contralaterally using a two-phase method. Three months after the implantation, the implant mobility was evaluated. Three measurements were performed with a Periotest device, and average values were calculated. The implant mobility was classified according to the Periotest scale in four groups of Periotest values (PTV) and compared. A total of 36 implants were inserted in 9 experimental dogs. The PTV ranged from -7.666 to + 50. RESULTS According to the Periotest scale, 14 one-phase implants (78%) were classified into the 0 group of PTV, and 4 one-phase implants (22%) in the 3rd group. Thirteen two-phase implants (72%) were classified in the 0 group, and 5 implants in the 3rd group of Periotest scale. The difference in the average values of PTV between the two methods was 0.879 which was not statistically significant. CONCLUSION This study showed that the method of implant insertion had no influence on the implant mobility, i.e. satisfactory osseointegration could be achieved by both methods. Further clinical parameters, as well as pathohistological and histomorphometric ones, have to be evaluated in order to assess better outcome of a particular method.