Kenan Eratalay

The possible association among bone density values, resonance frequency measurements, tactile sense, and histomorphometric evaluations of dental implant osteotomy sites: a preliminary study.

Purpose:The aim of the clinical preliminary trial was to determine the possible relationship among radiologic bone density, primary implant stability, and tactile sense measurements, and to clarify their possible association with histological measurements at endosseous implant osteotomy sites. Materials:Eleven mandibular and 12 maxillary sites of 10 patients were included. Computerized tomography was used for preoperative evaluation of the jaw-bone for each dental implant site, and bone densities were recorded in Hounsfield units (HU). Implant stability quotients (ISQ) were determined with the Osstell Mentor device. Bone core biopsies were taken from the implant osteotomy sites, where the tactile sense of the practitioner while placing the implants was also recorded. Results:The average radiologic bone density, primary implant stability, and trabecular bone volume (TBV) values were 554.87 HU, 72 ISQ, and 41% for 23 dental implants, respectively. Maxillary sites presented a statistically significant decrease HU values compared with sites in the mandible. The mean TBV in mandibles presented a trend of increase compared to maxillary sites. A significant correlation was noted between ISQ values and tactile sense for male patients, where HU values demonstrated significant correlations among ISQ values, TBV measurements, and tactile sense evaluations in women. Conclusions:The results of this study demonstrated that computerized tomography measurements in terms of HU evaluations may be a helpful technique for predicting primary stability of the implant and bone quality. Further studies should be performed to understand the relationship between clinical assessments and histological evaluations in implant osteotomy sites in humans.

Effects of Platelet-Rich Plasma and Chitosan Combination on Bone Regeneration in Experimental Rabbit Cranial Defects

This study aimed to investigate and compare the effect of chitosan sponge and platelet-rich plasma (PRP) gel alone as well as their combination on bone regeneration in rabbit cranial defects. Four cranial defects with a 4.5-mm diameter were created in rabbit cranium and grafted with PRP, chitosan sponge alone, and chitosan sponge incorporated with PRP. The rabbits were killed by the fourth and eighth weeks, and the defects were analyzed histologically. Higher bone formation was observed in the PRP group when compared with the other groups at weeks 4 and 8. All parts of the defects were filled with thick trabecular new bone in the PRP group. The amount of new bone formation in the control groups was found to be less when compared with the PRP group and the least in the chitosan group. The defects that were filled with chitosan sponge showed a limited amount of new bone formation and an obvious fibrous demarcation line between chitosan particles and bone. Application of PRP showed a histological tendency toward increased bone formation. Other forms or derivatives of chitosan may have beneficial effects to achieve new bone regeneration.

Evaluation of periodontal pathogens in amniotic fluid and the role of periodontal disease in pre-term birth and low birth weight

Abstract Background. Pre-term birth and/or low birth weight (PTLBW) is a serious problem in developing countries. The absence of known risk factors in ∼ 50% of PTLBW cases has resulted in a continued search for other causes. The aim of this study was to examine the effect of periodontitis on pregnancy outcomes. Methods. Samples were taken from 50 pregnant women who underwent amniocentesis. Polymerase chain reaction was performed on amniotic fluid samples obtained during amniocentesis and on subgingival plaque samples to determine the presence of Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Treponema denticola, Tannerella forsythia, Fusobacterium nucleatum, Prevotella intermedia, Campylobacter rectus and Eikenella corrodens. Plaque index, gingival index, bleeding on probing, probing depth and clinical attachment level were evaluated. Medical records were obtained after birth. Results. Social and demographic variables were similar among the Gingivitis (G), Localized Periodontitis (LP) and Generalized Periodontitis (GP) groups. Four subjects gave birth to PTLBW neonates. Campylobacter rectus, T. forsythia, P. gingivalis and F. nucleatum were detected in the amniotic fluid and subgingival plaque samples of three patients who gave birth to PTLBW neonates. The amniotic fluid sample from the fourth patient was not positive for any of the tested pathogens. Conclusion. These findings suggest that the transmission of some periodontal pathogens from the oral cavity of the mother may cause adverse pregnancy outcomes. The results contribute to an understanding of the association between periodontal disease and PTLBW, but further studies are required to better clarify the possible relationship.

Analysis of Human Gingival Tissue and Gingival Crevicular Fluid β-Glucuronidase Activity in Specific Periodontal Diseases

BACKGROUND β-glucuronidase (βG) is one of the enzymes involved in the destruction of non-collagenous components of the extracellular matrix. It is also considered an indicator or predictor of periodontal disease activity. The present study was conducted to determine the presence and the levels of βG activity in gingival tissue and gingival crevicular fluid (GCF) in periodontal disease and health status. The validity of 2 expressions of data, total βG activity versus βG concentration, and the correlations between clinical periodontal status and βG profile was also evaluated. METHODS βG activities in gingival tissues and GCF samples from 57 individuals, divided into 3 equal groups of adult periodontitis (AP), early-onset periodontitis (EOP), and periodontally healthy subjects were spectrophotometrically examined. RESULTS Both patient groups had higher βG levels in both gingiva and GCF than controls. Significant differences were observed among all groups when total GCF βG activities were examined (P <0.05). However, the difference between AP and controls was not significant when concentration values were compared (P >0.05). The highest GCF βG activity, with both expressions, was detected in EOP group. No absolute correlations between clinical parameters and βG activity were observed, except for random correlations in the patient groups with mean total βG activities. Also GCF/gingiva βG levels and the 2 expressions did not show absolute correlations. CONCLUSIONS The findings of the present study confirm the relationship between βG activity and periodontal diseases. The differences in data concerning GCF total βG activity and βG concentration may suggest that they are not matching measures. Data presentation seems to be an important factor in GCF/enzyme profile studies. J Periodontol 2000;71:618-624.

Analysis of the possibility of the relationship between various implant‐related measures: an 18‐month follow‐up study

Better clarification of the long-term relationship among the various implant-related measures could improve the evaluation process for dental implants. Thus, the aim of the present study was to determine the potential correlations among the volumetric features and nitric oxide content of peri-implant sulcus fluid (PISF) and measures of implant stability, and the marginal bone loss. Completely edentulous patients (n=15) treated with dental implants and ball attachment mandibular over dentures were included. Resonance frequency analysis (RFA), marginal bone level measurements, PISF volume and spectrophotometrically determined nitrite levels were recorded for all dental implant sites. Measures for early (n=16) and delayed (n=14) loaded dental implants were comparatively analysed for a period of 18 months. Some random correlations between PISF volume and marginal bone level, PISF nitrite level and marginal bone level and PISF volume and PISF nitrite content, and RFA and PISF volume were observed. However, the only constant correlation was noticed between implant stability (RFA scores) and marginal bone level. This correlation was negative and significant for all dental implants and for delayed loaded implants (P<0.05). The pattern of loading seemed to affect the extent, but not the pattern of this relationship. While some of the implant-related measures may be strongly associated (e.g. dental implant stability and marginal bone level), not all measures from a single implant site are likely to be related. Such associations may be under the influence of a variety of factors including the loading protocol of dental implants.

Effect of Porous Titanium Granules on Bone Regeneration and Primary Stability in Maxillary Sinus: A Human Clinical, Histomorphometric, and Microcomputed Tomography Analyses.

AbstractThe aim of this randomized controlled study was to comparatively analyze the new bone (NB), residual bone, and graft-bone association in bone biopsies retrieved from augmented maxillary sinus sites by histomorphometry and microcomputed tomography (MicroCT) in a split-mouth model to test the efficacy of porous titanium granules (PTG) in maxillary sinus augmentation. Fifteen patients were included in the study and each patient was treated with bilateral sinus augmentation procedure using xenograft (equine origine, granule size 1000–2000 &mgr;m) and xenograft (1 g) + PTG (granule size 700–1000 &mgr;m, pore size >50 &mgr;m) (1 g), respectively. After a mean of 8.4 months, 30 bone biopsies were retrieved from the implant sites for three-dimensional MicroCT and two-dimensional histomorphometric analyses. Bone volume and vital NB percentages were calculated. Immediate after core biopsy, implants having standard dimensions were placed and implant stability quotient values were recorded at baseline and 3 months follow-up. There were no significant differences between groups according to residual bone height, residual bone width, implant dimensions, and implant stability quotient values (baseline and 3 months). According to MicroCT and two-dimensional histomorphometric analyses, the volume of newly formed bone was 57.05% and 52.67%, and 56.5% and 55.08% for xenograft + PTG and xenograft groups, respectively. No statistically significant differences found between groups according to NB percentages and higher Hounsfield unit values were found for xenograft + PTG group. The findings of the current study supports that PTG, which is a porous, permanent nonresorbable bone substitute, may have a beneficial osteoconductive effect on mechanical strength of NB in augmented maxillary sinus.

Analysis of TNF-α (-308) polymorphism and gingival crevicular fluid TNF-α levels in aggressive and chronic periodontitis: A preliminary report

OBJECTIVES The purpose of this study was to determine the differences in the distribution of TNF-α (-308) gene polymorphism among aggressive periodontitis, chronic periodontitis and periodontally healthy individuals and also to investigate whether this polymorphism is associated with gingival crevicular fluid TNF-α levels and periodontal disease severity. MATERIAL AND METHODS A total of 93 individuals were enrolled in the study including 38 aggressive periodontitis, 29 chronic periodontitis patients, and 26 healthy controls. Single nucleotide polymorphism at TNF-α (-308) is analyzed by PCR-RFLP method. Gingival crevicular fluid samples were analyzed for TNF-α, using ELISA. RESULTS The distribution of genotypes and allele frequencies for TNF-α (-308) were similar among the groups. After stratification of patients with respect to attachment level, aggressive periodontitis patients with clinical attachment level ⩾4mm was observed to have a higher frequency of TNF-α (-308) allele 2 compared to the chronic periodontitis patients with clinical attachment level ⩾4mm. No significant differences were found between the TNF-α levels of the different genotypes in spite of an insignificant increase in patient groups carrying TNF-α (-308) allele 2. CONCLUSION The results of this study revealed an association between TNF-α (-308) allele 2 frequency and aggressive periodontitis patients with clinical attachment level ⩾4mm in the population studied.

Do Porous Titanium Granule Grafts Affect Bone Microarchitecture at Augmented Maxillary Sinus Sites? A Pilot Split-Mouth Human Study.

Background:The aim of this randomized controlled clinical study was to analyze the bone microarchitecture at augmented maxillary sinus sites by using different materials in patients to compare the effect of porous titanium granules as a sinus augmentation material with bone microstructural features. Materials and Methods:Eight subjects with bilateral atrophic posterior maxilla of residual bone height <4 mm included in this study and each patient was treated with bilateral sinus augmentation procedure using xenograft with equine origin (Apatos, Osteobiol; Tecnoss Dental) and xenograft (1 g) + porous titanium (1 g) granules (Natix; Tigran Technologies AB). Sixteen human bone biopsy samples were taken from patients receiving two-stage sinus augmentation therapy during implant installation and analyzed using microcomputerized tomography. Three-dimensional bone structural parameters were analyzed in details: tissue volume, bone volume, percentage of bone volume, bone surface and bone surface density, bone specific surface, trabecular thickness trabecular separation, trabecular number, trabecular pattern factor, structural model index, fractal dimension, and bone mineral density. Results:No statistically significant differences were found between groups according to bone structural parameters. Conclusions:Porous titanium grafts may ensure a space for new bone formation in the granules, which may be a clinical advantage for long-term success.

Characterization of peripheral blood and salivary gland lymphocytes in Sjögren's syndrome

Primary Sjögrens syndrome (SS) is an autoimmune disease resulting from lymphocyte infiltration of lacrimal and salivary glands (SG). This study was designed to investigate the peripheral blood (PBL) and SG lymphocytes in 14 patients with primary SS and control subjects. With the use of monoclonal antibodies, cells were stained to identify T-cells and T-cell subsets (T-helper and T-suppressor) and cells positive for HLA-DR antigen, whereas B cells were determined by the Smlg (surface membrane immunoglobulin) method. Lymphocytes in SG biopsy specimens were characterized by means of monoclonal antibodies and the immunoperoxidase technique. In the peripheral blood lymphocytes, there was a significant reduction in T cells and suppressor T cells. T lymphocytes and mostly helper T cells were predominant around the ducts and within the lymphocytic infiltrates in the minor SG biopsy samples of patients with SS. Suppressor T cells and B cells were found in fewer numbers, HLA-DR(+) cell populations had increased, and IgG- and IgA-bearing plasma cells were also present within the infiltrates. These results may contribute to our understanding of the immunopathogenesis of primary SS.