Aleksandra Petkovic-Curcin

Bone loss biomarkers associated with peri‐implantitis. A cross‐sectional study

AIM To investigate the levels of biomarkers associated with osteoclastogenesis in patients suffering peri-implantitis and to compare them with levels in healthy peri-implant sites and severe chronic periodontitis. MATERIAL AND METHODS Peri-implant/gingival crevicular fluid samples and clinical parameters including: bleeding on probing, modified Plaque Index (PlI), pocket depth and clinical attachment level were collected from 70 patients (23 with peri-implantitis, 25 with healthy peri-implant tissues and 22 with severe chronic periodontitis). The concentrations of sRANKL, RANK and OPG were evaluated using enzyme-linked immunosorbent assays; they were compared between the groups and correlated with the clinical findings. RESULTS sRANKL (P = 0.01), RANK (P = 0.01) and OPG (P = 0.03) concentrations were significantly higher in peri-implantitis sites when compared to those in healthy implant sites, although differences in the sRANKL/OPG ratio were not statistically significant. In these sites all three markers were significantly correlated with the clinical parameters, with exception of OPG/PI correlation that remained insignificant (P = 0.121). When comparing peri-implantitis and periodontitis findings, RANK was significantly higher in peri-implantitis sites whereas, sRANKL (P = 0.03) and sRANKL/OPG ratio (P = 0.004) were significantly higher in periodontitis sites. Among periodontitis and healthy implant sites the same differences have been observed for both sRANKL (P = 0.000) and sRANKL/OPG ratio (P = 0.000), furthermore RANK was higher in periodontitis sites as well (P = 0.010). CONCLUSION The findings of this preliminary study on a relatively small sample size suggest that the PICF levels of biomarkers sRANKL, RANK, and OPG are associated with peri-implant tissue destruction and the pattern of these biomarkers differed when compared to periodontitis.

Estimation of Bone Loss Biomarkers as a Diagnostic Tool for Peri-Implantitis

BACKGROUND The aims of this study are to estimate the profile of bone loss biomarkers in peri-implant tissues and to identify potential prognostic biomarkers of peri-implantitis. METHODS Peri-implant crevicular fluid samples collected from 164 participants (52 patients with peri-implantitis, 54 with mucositis, and 58 with healthy peri-implant tissues) were analyzed using enzyme-linked immunosorbent assays to evaluate concentrations of the receptor activator of nuclear factor-κB (RANK), soluble RANK ligand (sRANKL), osteoprotegerin (OPG), cathepsin-K, and sclerostin. RESULTS Concentrations of RANK, sRANKL, OPG, and sclerostin were significantly increased in patients with peri-implantitis compared with patients with healthy peri-implant tissues. Comparisons between peri-implantitis and mucositis demonstrated significantly higher values of sclerostin in peri-implantitis samples. Comparisons between mucositis and healthy peri-implant tissues showed significantly increased levels of RANK and cathepsin-K in mucositis. CONCLUSION These results are suggestive of a role of sRANKL, OPG, and sclerostin as prognostic biomarkers in peri-implantitis.

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.

Association of Cytokine Gene Polymorphism with Peri-implantitis Risk

PURPOSE To investigate whether polymorphisms of cluster of differentiation 14 (CD14), tumor necrosis factor alpha (TNFα), interleukin (IL)6, IL10, and IL1ra genes are associated with the risk of peri-implantitis susceptibility in patients with dental implants in the Serbian population. MATERIALS AND METHODS Isolated DNA from the blood was used for IL10-1082, TNFα-308, IL6-174, CD14-159, and interleukin 1 receptor antagonist (IL1ra) genotyping using polymerase chain reaction (PCR)-based methodology. Clinical parameters included: peri-implant pocket depth (PPD), Plaque Index (PI), Gingival Index (GI), bleeding on probing (BOP), and radiologic bone loss. RESULTS The study included 98 patients with dental implants in function for at least 1 year, divided into peri-implantitis (34) and healthy peri-implant tissue (64) groups. The percentage distribution of smokers was significantly different between patients who developed peri-implantitis and patients with healthy peri-implant tissue (71% vs 42%, respectively) and associated with increased peri-implantitis risk (OR: 3.289, 95% CI: 1.352 to 8.001; P = .007). A positive history of periodontitis was more frequent in the peri-implantitis group (62%) than in the healthy peri-implant tissue (20%) group and associated with increased peri-implantitis risk (OR: 6.337, 95% CI: 2.522 to 15.927; P = .0001). Frequencies of CD14-159, TNFα-308, IL10-1082, and IL6-174 genotypes were significantly different between patients with and without peri-implantitis. However, logistic regression revealed only TNFα-308 polymorphic GA/AA genotypes (OR: 8.890, 95% CI: 2.15 to 36.7; P = .003) and smoking (OR: 6.2, 95% CI: 1.44 to 26.7; P = .014) as independent factors associated with increased peri-implantitis risk, while CD14-159 polymorphic CT/TT genotypes were associated with decreased risk for peri-implantitis (OR: 0.059, 95% CI: 0.009 to 0.355; P = .002). CONCLUSION The findings suggest that smoking and the presence of TNFα-308 GA/AA genotypes may increase the risk for peri-implantitis, while CD14-159 polymorphic CT/TT genotypes decrease the risk. The results also indicate significant association of CD14-159, TNFα-308, and IL6-174 genotypes and clinical parameters in the Serbian population. However, future studies in larger patient groups are necessary to confirm these observations.

Influence of Dental Restorations on Oxidative Stress in Gingival Crevicular Fluid

Biocompatibility of dental materials (DM) can be evaluated by gingival crevicular fluid (GCF) oxidative stress (OS) status. The goal of the study was to ascertain influence of dental caries degree, teeth position, and type and amount of applied DM on GCF OS profile. For this purpose, we tested six DMs that were sealed in one session: amalgam (Amg), composites: Tetric EvoCeram and Beautifil (BF), phosphate cement—zinc phosphate and polycarboxylate cements—zinc polycarboxylate cements, and glass ionomer cement (GIC). The study included 88 dental outpatients. Follow-up was scheduled at 7th and 30th day. Oxidative stress parameters (malondialdehyde (MDA) and glutathione (GSH) levels and total superoxide dismutase (tSOD) activity) were measured before (0th day) and after the treatment (7th and 30th day) in GCF. Control teeth were mirror-positioned healthy teeth. The DM accomplished the following effects (listed in descending order): increase of GSH in GCF was realized by ZPoC > BF > GIC > Amg; tSOD activity increase by ZPoC > BF > Amg; and MDA decrease by ZPoC > ZPhC > Amg > TEC. Dental caries provokes insignificant rise of OS in GCF. ZPoC and ZPhC showed the highest antioxidant effect, contrary to GIC. Restorations with antioxidant properties may reduce gum diseases initiated by caries lesion, what is of great clinical relevance in dentistry.

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