Andreea Didilescu

Salivary biomarkers: Relationship between oxidative stress and alveolar bone loss in chronic periodontitis

Abstract Objectives. Oxidative stress is implicated in the pathogenesis of many systemic and oral diseases such as periodontal disease. The main aim of this study is to explore a possible association between salivary markers of OS and alveolar bone loss. Materials and methods. The study included 20 patients with chronic periodontitis and 20 controls. Salivary OS biomarkers 8-hidroxy-desoxguanosine (8-HOdG), malondialdehyde (MDA), uric acid, total antioxidant capacity (TAC) and glutathione peroxidase (GPx) were evaluated. Bone loss markers such as C-terminal telopeptide of type I collagen (CTX I), matrix metalloproteinases-8 (MMP-8), osteocalcin and 25-hydroxy vitamin D3 (25- OH D) were detected in this study. The methods included general biochemical tests and ELISA. Results. Salivary 8-OHdG, MDA levels were significantly higher in the chronic periodontitis group compared with controls (p < 0.05). Salivary activities for uric acid, TAC and GPx were significantly decreased in patients with chronic periodontitis vs controls (p < 0.05). Salivary levels for CTX I, MMP-8, 25-OH D and Osteocalcin were significantly higher in the chronic periodontitis group compared to the controls (p < 0.05). A significant positive correlation was observed between salivary levels of MDA and CTX I. Significant negative correlations between uric acid and CTX I and between MMP-8 and uric acid have been found. Significant positive correlations were observed between CTX I, MMP-8, 25-OH D, osteocalcin and clinical parameters of periodontal disease. Conclusions. Important oxidative stress associated with alveolar bone loss biomarkers can be detected in saliva of patients with periodontal disease.

Quantitative and qualitative bone analysis in the maxillary lateral region

PurposesThe present study was conducted to assess the amount of bone present between root apices and the maxillary sinus floor in the maxillary lateral region, to compare the evaluations on cone beam computed tomography (CBCT) and orthopantomography (OPG), and to evaluate the bone density of the same region using three-dimensional images on CBCT.MethodsFifty-one dental patients were recruited for the study. All subjects were partially edentulous. The distances from the maxillary premolars and molars apices to the maxillary sinus floor were assessed using CBCT and OPG. Color codes were assigned to the bone density of edentulous loci. Parametric and non-parametric tests were used for statistical analyses. A p value <0.05 was considered statistically significant.ResultsThe maxillary first and second molars recorded the shortest mean distances to the sinus floor, in contrast to the maxillary first premolar. The bone density of the maxillary lateral area increased from the maxillary first premolar to the second molar. No statistical significant differences were found between the evaluated sites.ConclusionsOur results provide estimates of the minimal and maximal distances between teeth and sinus, as well as the average bone density in the maxillary lateral region. It is important that evaluation of a specific patient be performed during the preoperative planning of implants.

Suburothelial Interstitial Cells

The suburothelium has received renewed interest because of its role in sensing bladder fullness. Various studies evaluated suburothelial myofibroblasts (MFs), interstitial cells (ICs), interstitial Cajal cells (ICCs) or telocytes (TCs), which resulted in inconsistencies in terminology and difficulties in understanding the suburothelial structure. In order to elucidate these issues, the use of electron microscopy seems to be an ideal choice. It was hypothesized that the cell population of the suburothelial band is heterogeneous in an attempt to clarify the above-mentioned inconsistencies. The suburothelial ICs of the bladder were evaluated by immunohistochemistry (IHC) and transmission electron microscopy (TEM). Bladder samples from 6 Wistar rats were used for IHC and TEM studies and human bladder autopsy samples were used for IHC. Desmin labeled only the detrusor muscle, while all the myoid structures of the bladder wall were positive for α-smooth muscle actin (SMA). A distinctive α-SMA-positive suburothelial layer was identified. A layered structure of the immediate suburothelial band was detected using TEM: (1) the inner suburothelial layer consisted of fibroblasts equipped for matrix synthesis; (2) the middle suburothelial layer consisted of smooth muscle cells (SMCs) and myoid ICCs, and (3) the outer suburothelial layer consisted of ICs with TC morphology, building a distinctive network. In conclusion, the suburothelial layer consists of distinctive types of ICs but not MFs. The myoid layer, with SMCs and ICCs, which could be considered identical to the α-SMA-positive cells in the suburothelial band, seems the best-equipped layer for pacemaking and signaling. Noteworthy, the network of ICs also seems suitable for stromal signaling.

The mandibular ridge oral mucosa model of stromal influences on the endothelial tip cells: an immunohistochemical and TEM study.

This study aimed to evaluate by immunohistochemistry and transmission electron microscopy (TEM) the morphological features of the oral mucosa endothelial tip cells (ETCs) and to determine the immune and ultrastructural patterns of the stromal nonimmune cells which could influence healing processes. Immune labeling was performed on bioptic samples obtained from six edentulous patients undergoing surgery for dental implants placement; three normal samples were collected from patients prior to the extraction of the third mandibular molar. The antibodies were tested for CD34, CD117(c‐kit), platelet derived growth factor receptor‐alpha (PDGFR‐α), Mast Cell Tryptase, CD44, vimentin, CD45, CD105, alpha‐smooth muscle actin, FGF2, Ki67. In light microscopy, while stromal cells (StrCs) of the reparatory and normal oral mucosa, with a fibroblastic appearance, were found positive for a CD34/CD44/CD45/CD105/PDGFR‐α/vimentin immune phenotype, the CD117/c‐kit labeling led to a positive stromal reaction only in the reparatory mucosa. In TEM, non‐immune StrCs presenting particular ultrastructural features were identified as circulating fibrocytes (CFCs). Within the lamina propria CFCs were in close contact with ETCs. Long processes of the ETCs were moniliform, and hook‐like collaterals were arising from the dilated segments, suggestive for a different stage migration. Maintenance and healing of oral mucosa are so supported by extensive processes of angiogenesis, guided by ETCs that, in turn, are influenced by the CFCs that populate the stromal compartment both in normal and reparatory states. Therefore, CFCs could be targeted by specific therapies, with pro‐ or anti‐angiogenic purposes. Anat Rec, 2013.

A 3D cone beam computed tomography study of the styloid process of the temporal bone

BACKGROUND To investigate the length and three-dimensional orientation and to detail the morphological variations of the styloid process. MATERIALS AND METHODS Forty-four patients undergoing temporal bone evaluation for different reasons were randomly selected and included in the present study. The length, angulation in the coronal and sagittal planes, as well as morphological variations of the styloid processes were assessed using conebeam computer tomography. Pearsons correlation coefficient was used to test possible associations between the length of styloid process and angulations, as well as between angulations. Students t-test was used to compare the differences between the sample mean length and angulations in normal and elongated styloid process groups. RESULTS The sagittal angle showed weak positive correlations with the styloid process length and the transverse angle (r = 0.24, p = 0.02, n = 88). A medium positive correlation was found between the sagittal and transverse angulations in the elongated styloid process group (r = 0.49, p = 0.0015, n = 38). There was a statistical significant difference between the mean sagittal angulation in elongated styloid and normal styloid process groups (p = 0.015). The styloid process morphology also varied in terms of shape, number, and degree of ossification. CONCLUSIONS The morphometric and morphologic variations of the styloid process may be important factors to be taken into account not only from the viewpoint of styloid syndromes, but also in preoperatory planning and during surgery.

Prospective clinical study evaluating the long-time adjunctive use of chlorhexidine after one-stage full-mouth SRP.

OBJECTIVES Scaling and root planing are the causal procedure in the treatment of periodontitis. Many attempts have been made to improve the outcome. The aim of this study was to verify the influence of the extended use of chlorhexidine after one-stage full-mouth (FM) SRP in patients with chronic periodontitis on the clinical outcome after 3 months. METHODS Eighty-one patients with pockets > or =5 mm were treated by FM. All patients rinsed additionally with 0.2% chlorhexidine (CHX) twice daily over 3 months. Plaque index, bleeding on probing, probing depth (PD) and clinical attachment level (CAL) were recorded at baseline and after 1 and 3 months. RESULTS In the test group, all variables were significantly improved after 1 and 3 months. Mean reduction of PD and CAL gain was 2.25 +/- 1.08 and 1.67 +/- 1.08 after 1 and 2.99 +/- 1.11 and 2.33 +/- 1.31 after 3 months respectively. CONCLUSIONS Over 3 months of extended use of CHX mouth rinse after SRP showed slightly but statistically significant better results.

Evaluation of a hydrophobic gel adhering to the gingiva in comparison with a standard water‐soluble 1% chlorhexidine gel after scaling and root planing in patients with moderate chronic periodontitis. A randomized clinical trial

Objectives: To evaluate the clinical, microbiological and enzymatic activity of a hydrophobic chlorhexidine‐based gingiva‐adhering gel containing herbal ingredients, compared with a commercially available 1% chlorhexidine water‐soluble gel, during non‐surgical therapy of moderate chronic periodontitis. Methods: A total of 34 subjects participated in this 6‐month blinded randomized parallel controlled trial (ISRCTN35210084). After scaling and root planing (SRP), test group received the gel, by rubbing on the gingiva, once every second day, for 14 days. The control group received the control gel twice daily. Clinical parameters considered were the approximal plaque index, simplified oral hygiene index, modified gingival index, bleeding on probing, probing depth and clinical attachment level (primary outcome), assessed at baseline, 3 and 6 months, together with the frequency of detection of Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis (P.g.), Prevotella intermedia, Treponema denticola (T.d.), Tannerella forsythia (T.f.), and activity of neutrophil elastase and myeloperoxidase (secondary outcomes). Results: At 3 and 6 months, all clinical parameters improved significantly, without significant intergroup differences, except OHI‐S, which improved at 3 months (P < 0.05). Microbiological data resulted in no significant intergroup differences at baseline and 6 months. At 3 months, significant differences for P.g., T.f. and T.d. were noted. A significant reduction of neutrophil elastase after 3 and 6 months was observed (P < 0.005), without significant intergroup differences. For myeloperoxidase, significant reductions were noted in both groups (P < 0.005 and P < 0.05), but no significant intergroup differences. The tested product seemed to have an increased efficacy, due to longer persistence on the gingiva, with reduced application frequency. Conclusions: Both products had a relatively similar influence on the clinical, microbiological and enzymatic outcomes at 3 and 6 months after SRP.

Anoctamin 1 Positive Esophageal Interstitial Cajal Cells in Late Stage Human Embryos

Interstitial cells of Cajal (ICCs) are located in various smooth muscle organs and act as pacemaker cells, or ensure neuromodulation or mechanosensory roles. The study aims to investigate functional states of human ICCs in morphogenesis, focusing on the anoctamin 1 phenotype. The investigation was performed in five late stage human embryos with lengths varying between 23 and 29 mm. Immunohistochemistry on paraffin embedded specimens was performed for a series of antibodies: α‐smooth muscle actin (α‐SMA), desmin, CD31, CD34, CD117/c‐kit, DOG1, and nestin. Longitudinal and circular muscle layers were α‐SMA+/desmin+/nestin+. An immature microvascular layer located in the inner submucosa was CD34+/CD31+/α‐SMA+/nestin+; endothelial tip cells were supporting active processes of sprouting angiogenesis. A CD34+/CD31‐ mesenchymal network was found in the circular muscle layer. CD117/c‐kit+ multipolar ICCs with dichotomizing processes were found mostly in the myenteric plexus layer; processes were configuring a network within the circular muscle layer where intramuscular ICCs were scarcely found. A strong DOG1+ reaction was found for the ICCs of the myenteric plexus layer apposed on the outer surface of the circular muscle layer, and for the intramuscular ICCs. The evidence of a sublayer of DOG1+ myenteric ICCs is suggestive for a subpopulation of ICCs being qualified for pacemaking at this early developmental stage. Anat Rec, 297:301–307, 2014.

c-kit positive cells and networks in tooth germs of human midterm fetuses

Numerous studies have attempted to characterize the dental pulp stem cells. However, studies performed on prenatal human tissues have not been performed to evaluate the in situ characterization and topography of progenitor cells. We aimed to perform such a study using of antibodies for CD117/c-kit and multiplex antibody for Ki67+ caspase 3. Antibodies were applied on samples dissected from five human midterm fetuses. Positive CD117/c-kit labeling was found in mesenchymal derived tissues, such as the dental follicle and the dental papilla. The epithelial tissues, that is, dental lamina, enamel organ and oral epithelia, also displayed isolated progenitor cells which were CD117/c-kit positive. Interestingly, CD117/c-kit positive cells of mesenchymal derived tissues extended multiple prolongations building networks; the most consistent of such networks were those of the dental follicle and the perivascular networks of the dental papilla. However, the mantle of the dental papilla was also positive for CD117/c-kit positive stromal networks. The CD117/c-kit cell populations building networks appeared mostly with a Ki67 negative phenotype. The results suggest that CD117/c-kit progenitor cells of the prenatal tooth germ tissues might be involved in intercellular signaling.

Periodontal materials and cell biology for guided tissue and bone regeneration

The present review is intended to find links between periodontal materials of the dentomaxillary apparatus and cell biology at the beginning of a century fraught with various forms of periodontal diseases and needing new treatment strategies. The manuscript has two different parts. The first describes the anatomy of tooth supporting structures, as well as related pathologies. The second part is related to cell and molecular biology in the context of periodontal regeneration.