Impact of dental implant insertion method on the peri-implant bone tissue: 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, α = 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, α = 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 periimplantitis 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 periimplantitis 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 periimplant/ 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

Uticaj resorptivne membrane humanog porekla na regeneraciju koštanog tkiva - patohistološka studija

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 μ 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 μ 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 defects 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.Uvod/Cilj. Popunjavanje koštanih defekata zamenicima kosti je terapija izbora, ali prorastanje vezivnog tkiva iz mukoperiostalnog režnja može kompromitovati sam proces zarastanja zamenika kosti sa zidovima koštanih defekata. U cilju rešavanja ovog problema indikovana je primena membrane kao barijere. Cilj ove studije bio je da se prikaže patohistološki izgled koštane regeneracije i značaj resorptivne demineralizovane membrane humanog porekla (RHDM), debljine 200 mikrona, u regeneraciji kosti kod mandibularnih defekata u eksperimentu rađenom na psima. Metode. Eksperiment je vršen na šest pasa kojima je sa desne strane donje vilice, po podizanju mukoperiostalnog režnja, pravljen koštani defekt. U jedan defekt stavljana je humana deproteinizovana kost (HDK), a između nje i mekotkivnog dela stavljana je RHDM debljine 200 mikrona. U drugi defekt, koji je služio kao kontrola, stavljena je samo HDK, bez RHDM. Dva psa žrtvovana su dva meseca nakon hirurške intervencije, dva posle četiri meseca, a preostala dva šest meseci nakon hirurške intervencije. Nakon žrtvovanja uzimani su isečci za patohistološku analizu. Rezultati. Kod svih šest pasa kod kojih je u koštani defekt ugrađena HDK i RHDM stepen koštane regeneracije bio je daleko veći u odnosu na kontrolne defekte bez RHDM. Zaključak. Membrana, kao pokrivač koštanog defekta, podesna je i poboljšava koštanu regeneraciju. Koštani defekti prekriveni RHDM pokazali su značajno bolje koštano zarastanje, mada koštana regeneracija nije bila potpuna ni šest meseci nakon njene ugradnje

Povezanost kliničkih parametara i prisustva Aggregatibacter actinomycetemcomitans i Porphyromonas gingivalis kod pacijenata sa progresivnim parodontalnim lezijama

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.Uvod/Cilj. Parodontopatija je hronično inflamatorno oboljenje parodontalnih tkiva koje za krajnji ishod ima gubitak potpornog koštanog tkiva zuba usled imunoloških reakcija izazvanih parodontopatogenim bakterijama. Cilj studije bio je korelisanje kliničkih parametara i prisustva dve najagresivnije parodontopatogene bakterije (Aggregatibacter actinomycetemcomitans - A.a. i Porphyromonas gingivalis - P.g.) kod bolesnika sa progresivnim parodontalnim lezijama. Metode. U studiju su bila uključena 34 sistemski zdrava ispitanika, starost 23-70 godina. Ispitanici su klinički i radiološki pregledani i uzorak je uziman iz reprezentativnog parodontalnog džepa sa najvećom dubinom sondiranja. Od kliničkih parametara mereni su gingivalni indeks, indeks krvarenja gingive, dubina parodontalnog džepa i indeks plaka. Prisustvo parodontopatogena dokazivano je multipleks metodom PCR (Polymerase Chain Reaction), a rezultati su korelisani sa kliničkim parametrima primenom odgovarajućih statističkih testova. Rezultati. Ista procentualna zastupljenost oba mikroorganizma dokazana je u uzorcima, naime i A.a. i P.g. bili su prisutni u po 35,39% uzoraka, a u 29,41% dokazana su oba mikroorganizma. Rezultati su korelisani po grupama formiranim u odnosu na prisustvo bakterija. Vrednosti merenih kliničkih parametara nisu se statistički značajno razlikovale u zavisnosti od prisustva parodontopatogena. Međusobne korelacije kliničkih parametara unutar grupe nisu pokazale statističku značajnost, osim korelacije gingivalnog i plak indeksa u grupi sa A.a. Zaključak. Klinički tok uznapredovale faze parodontopatije ne razlikuje se u odnosu na vrstu parodontalnih bakterija kao induktora imunološki posredovanih destruktivnih procesa

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-β, 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 CTPRP. 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

Cytokines in pathogenesis of peri-implantitis

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Salivary interleukin-8 levels in children suffering from Type 1 diabetes mellitus

Objective: The aim of this study was to investigate the differences between the salivary levels of IL-8 in patients with Type I diabetes mellitus (DM) with (DM+P) or without (DM-P) concomitant periodontitis and healthy subjects. The correlations between the levels of these cytokines and clinical periodontal parameters were also established Methods: Twenty children and adolescents with Type I DM (10 diagnosed with periodontitis, 10 presenting no signs of periodontitis) and a control group consisting of 20 healthy children and adolescents aged 7-18 years were recruited for this study. Results: The Salivary IL-8 level was statistically significantly (p lt 0.005) elevated in subjects with Type 1 DM (474.47 +/- 716.76) compared to non-diabetic control group (101.99 +/- 68.32). There was no difference (p>0.05) in the salivary IL-8 level when subjects with Type I DM with concomitant periodontitis were compared to diabetics without periodontitis. When the salivary IL-8 level in subjects with Type I DM was correlated with the clinical parameters, no statistical significance was found Conclusion: An elevated salivary IL-8 level in subjects with Type 1 DM without concomitant periodontitis plays a major role in the development of diabetic micro and macroangiopathy and pathogenesis of atherosclerosis. Consequently, this may offer a basis for the assessment of risk, prophylaxis and treatment of diabetic complications

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 mambrane 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