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

OBJECTIVES: This 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 METHODS: Study 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. RESULTS: Analysis 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. CONCLUSION: Within 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 RELEVANCE: Investigated 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.

Impact of dental implant insertion method on the peri-implant bone tissue--an experimental study.

BACKGROUND/AIM: The function of dental implants depends on their stability in bone tissue over extended period of time, i.e. on osseointegration. The process through which osseointegration is achieved depends on several factors, surgical insertion method being one of them. The aim of this study was to histopathologically compare the impact of the surgical method of implant insertion on the peri-implant bone tissue. METHODS: The experiment was performed on 9 dogs. Eight weeks following the extraction of lower premolars implants were inserted using the one-stage method on the right mandibular side and two-stage method on the left side. Three months after implantation the animals were sacrificed. Three distinct regions of bone tissue were histopathologically analyzed, the results were scored and compared. RESULTS: In the specimens of one-stage implants increased amount of collagen fibers was found in 5 specimens where tissue necrosis was also observed. Only moderate osteoblastic activity was found in 3 sections. The analysis of bone-to-implant contact region revealed statistically significantly better results regarding the amount of collagen tissue fibers for the implants inserted in the two-stage method (Wa = 59 < 66.5, alpha = 0.05), but necrosis was found in all specimens, and no osteoblastic activity. Histopathological analysis of bone-implant interface of one-stage implants revealed increased amount of collagen fibers in all specimens, moderate osteoblastic activity and neovascularization in 2 specimens. No inflammation was observed. The analysis of two-stage implants revealed a marked increase of collagen fibers in 5 specimens, inflammation and bone necrosis were found in only one specimen. There were no statistically significant differences between the two methods regarding bone-implant interface region. Histopathological analysis of bone tissue adjacent to the one-stage implant revealed moderate increase of collagen tissue in only 1 specimen, moderate increase of osteoblasts and osteocytes in 3 specimens. No necrotic tissue was found. The analyzed specimens of bone adjacent to two-stage implants revealed a moderate increase in the number of osteocytes in 3 and a marked increase in 6 specimens respectively. This difference was statistically significant (Wb = 106.5 > 105, alpha = 0.05). No necrosis and osteoblastic activity were observed. CONCLUSION: Better results were achieved by the two-stage method in bone-to-implant contact region regarding the amount of collagen tissue, while the results were identical regarding the osteoblastic activity and bone tissue necrosis. There was no difference between the methods in the bone-implant interface region. In the bone tissue adjacent to the implant the results were identical regarding the amount of collagen tissue, osteoblastic reaction and bone tissue necrosis, while better results were achieved by the two-stage method regarding the number of osteocytes.

Receptor activator of nuclear factor kappa B (RANK) as a determinant of peri-implantitis.

BACKGROUND/AIM: Peri-implantitis presents inflammatory process that affects soft and hard supporting tissues of osseointegrated implant based on inflammatory osteoclastogenesis. The aim of this study was to investigate whether receptor activator of nuclear factor kappa B (RANK) concentrations in peri-implant crevicular fluid could be associated with clinical parameters that reflect inflammatory nature of peri-implantitis. METHODS: The study included 67 patients, 22 with diagnosed peri-implantitis, 22 persons with healthy peri-implant tissues and 23 patients with periodontitis. Clinical parameters from each patient were recorded and samples of peri-implant/gingival crevicular fluid were collected for the enzyme-linked immunosorbent assay (ELISA) analysis. RESULTS: RANK concentration was significantly increased in samples from the patients with peri-implantitis when compared to healthy implants (p < 0.0001), where the average levels were 9 times higher. At the same time RANK concentration was significantly higher in peri-implantitis than in periodontitis sites (p < 0.0001). In implant patients pocket depths and bleeding on probing values were positively associated with high RANK concentrations (p < 0.0001). CONCLUSION: These results revealed association of increased RANK concentration in samples of peri-implant/gingival crevicular fluid with peri-implant inflammation and suggests that RANK could be a pathologic determinant of peri-implantitis, thereby a potential parameter in assessment of peri-implant tissue inflammation and a potential target in designing treatment strategies.

[Histopathological evaluation of bone regeneration using human resorbable demineralized membrane].

BACKGROUND/AIM: Filling a bone defect with bone substitution materials is a therapy of choice, but the infiltration of connective tissue from the mucoperiostal flap may compromise a healing of bone substitutions with bony wall defects. Application of membrane as a barrier is indicated as a solution to this problem. The aim of this study was to show a pathohistological view of bone regeneration and the significance of human resorbable demineralized membrane (HRDM), 200 microns thick in bone regeneration regarding mandibular defects in an experiment on dogs. METHODS: The experiment was performed on six dogs. Bone defects were created in all six dogs on the right side of the mandible after the elevation of the mucoperiostal flap. One defect was filled with human deproteinised bone (HDB), and in between HDB and soft tissue RHDM of 200 microns thick was placed. In the second defect, used as a control one, only HDB without RHDM was placed. Two dogs were sacrificed two months after the surgery, another two dogs four months after the surgery and the last two dogs six months after the surgery. After that, samples of bone tissue were taken for histopathological analysis. RESULTS: In all the six dogs with defects treated with HDB and RHDM the level of bone regeneration was much higher in comparison with the control defects without RHDM. CONCLUSION: Membrane, as a cover of bony defect, is useful and benefits bone regeneration. Bony de fects covered with RHDM show better bony healing despite the fact that bone regeneration was not fully complete for as long as six months after the RHDM implantation.

[Impact of dental implant insertion method on the periimplant epithelial seal--experimental study on dogs].

BACKGROUND/AIM: There is a controversial opinion among implantologists on the method of dental implantation that provides more favourable response of soft and bone tissues. The aim of this study was to pathohistologicaly compare the influences of one- and two-phase implant surgical methods on the periimplant epithelial tissues. METHODS: The experiment was performed on 10 dogs. Eight weeks following tooth extractions implants were inserted using one phase method on the right side of the mandible, and two-phase method on the left one. Three months after implantation the animals were sacrificed. Contact regions of epithelial and subepithelial tissues and implants were pathohistologicaly examined, the elements of analysis were scored and compared. RESULTS: Epithelial tissue was not found in the two samples of one-phase implants, while in the remainder of samples the structure of basal membrane was preserved, massive inflammatory infiltrate was found in one, and partial necrosis was found in three samples. Epithelial tissue was not found in the three samples of two-phase implants, in three samples the structure of basal membrane was intact, while in three remained samples the membrane could not be detected; moderate inflammatory infiltrate was found in four samples and massive inflammatory infiltrate in both two remained samples; tissue necrosis, which was observed in the half of the samples, was complete. In subepithelial gingival tissues around one-phase implants the number of blood vessels was increased in three samples, accompanied by the thickening and dilatation of vascular walls, proliferation of blood elements, altered vascular walls and inflammatory cell infiltrate was found in four samples. CONCLUSION: On the base of the analized characteristics of epithelial and subepithelial tissues in contact with dental implants, one-phase method of implantation showed a more favorable tissue response.

[Association between clinical parameters and the presence of Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis in patients with progressive periodontal lesions].

BACKGROUND/AIM: Periodontitis is a chronic inflammatory disease of periodontal tissues with consequential is bone loss as a result of host immunological reactions caused by periopathogens. The aim of the study was to investigate if there is a correlation between clinical parameters and the presence of two most aggressive periopathogens (Aggregatibacter actinomycetemcomitans--Aa and Porphyromonas gingivalis--Pg) in patients with progressive periodontal lesions. METHODS: A total of 34 systemic healthy people, 23 to 70 years old, were included in the study. The patients were clinically and radiologically examined, and after that, the representative pocket with greatest pocket depth was chosen and the sample was collected from that place. The measured clinic parameters were: gingival index, index of gingival bleeding, pocket depth and plaque indices. The multiplex Polymerase Chain Reaction (PCR) method was used for detection of periopathogens. After obtaining results, appropriate statistical tests were used to correlate the clinical and microbiological results. RESULTS: Aa and Pg were detected in the same percentage of samples. Aa and Pg were detected in 35.29% samples alone, and in 29.41% both were detected. The values of measured clinical parameters did not show a statistical significance between the groups. In analysis of correlations among clinical parameters inside the groups, a statistical significance was found only between gingival and plaque index in the group with Aa. CONCLUSION: Clinical course of periodontitis in the developed stage does not differ in relation to the presence of different periopathogens as the major inductors of immunologically guided destructive processes.

Clinical parameters of the local anesthetic effects of bupivacaine applied with and without a vasoconstrictor in oral implantology.

BACKGROUND/AIM: Bupivacaine (Marcaine), homologue of mepivacaine, chemically related to lidocaine, is used as a local anesthetic for local infiltration, peripheral nerve block, retrobulbar block, symphathetic block, and caudal and epidural anesthesia. The aim of this investigation was to determine and to compare clinical parameters of the local anesthetic effects of bupivacaine applied with and without a vasoconstrictor. METHODS: This investigation included a total of 30 randomly selected patients, who ranged in age from 30-60 years, with partial or total anodontia in the molar region of the mandible. These patients with total or partial edentulous molar part of the mandible, scheduled for dental implantation placement, were asked to participate in the study. In the first phase of the investigation, the patients were subjected to local anesthesia with 3.5 cm3 of 0.5% bupivacaine with a vasoconstrictor (adrenalin, 1: 200,000) in the right side of the mandible. After administering local anesthesia, the placement of blade, cylindrical, transdental (B.C.T.) implants was performed. In the second stage of the investigation, in 7-10 days period after the first oral surgery, the patients were subjected to local anesthesia with 3.5 cm3 of 0.5% bupivacaine, but without a vasoconstrictor, in the left side of the mandible. After administering local anesthesia, the placement of B.C.T. implants was performed. During the performance of both oral surgery procedures, the following clinical parameters of the local anesthetic effects were monitored: latent period, duration and the potency of anesthesia, and the evaluation of the postoperative pain level. RESULTS: The latent period under local anesthesia with 3.5 cm3 of 0.5% bupivacaine and vasoconstrictor was statistically significantly shorter than without vasoconstrictor. The duration of local anesthesia was longer without vasoconstrictor. There was no difference in the potency of anesthesia with or without a vasoconstrictor, while the lowest level of postoperative pain was found after administering bupivacaine without a vasoconstrictor use. CONCLUSION: The results of this investigation show that bupivacaine without a vasoconstrictor is efficient when used for local anesthesia in placing dental implants since it provides better blood circulation required for good dental implant osseointegration.

[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.

[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.