Matteo Piemontese

Involvement of vascular endothelial growth factor, CD44 and CD133 in periodontal disease and diabetes: an immunohistochemical study.

AIM The aim of this study was to investigate the relationship between expression of angiogenic and regeneration markers and periodontal disease in subjects with/without diabetes mellitus. MATERIAL AND METHODS Immunohistochemical detection of vascular endothelial growth factor (VEGF), CD44 and CD133 was performed in 16 samples each of (1) healthy gingiva from non-diabetic subjects (controls), (2) gingiva from non-diabetic subjects with periodontitis, (3) gingiva from subjects with type 1 diabetes and periodontitis, (4) gingiva from subjects with type 2 diabetes and periodontitis. RESULTS Diseased gingivae from patients with diabetes and periodontitis had greater clinical measures of periodontal disease than those with periodontitis only. VEGF expression was significantly enhanced in epithelial and endothelial cells from patients with periodontitis compared with controls (p<0.05). Epithelial CD44 expression was strong in all groups, while CD44 was significantly enhanced (p<0.05) in connective tissue cells from both diabetic groups. Epithelial and endothelial CD133 expression was comparable in all patients except those with type 2 diabetes and periodontitis, where it was not detected. Stromal CD133 expression was significantly lower in patients with type 2 diabetes and periodontitis and was increased in periodontitis patients (p<0.05). CONCLUSIONS The involvement and high expression of VEGF, CD44 and CD133 in periodontal disease may predict a greater regeneration capacity of gingival tissue.

Technical and biological complications related to crown to implant ratio: a systematic review.

Aim:To review the occurrence of prosthetic failure and biological complications with respect to the crown to implant (C/I) ratio. Methods:Accurate search was made on the subject C/I ratio with the following criteria: (1) studies on humans with data on prosthetic failure and/or biological complications related to C/I ratio; (2) partial edentulous patients; (3) randomized clinical trials, prospective, longitudinal, retrospective, and multicenter studies with a minimum of 48 months mean follow-up; (4) language: English; (5) radiographic measurements by peri-apical x-ray; (6) implant material: titanium; and (7) no implant type selection was applied. Results:Six articles were considered eligible for full-text analysis. Unfavorable C/I ratio can be considered a potential risk factor for single crown and abutment loosening (C/I ratio ≥1.46) and abutment fractures in posterior areas (C/I ratio ≥2.01). Conclusions:Despite the limited data, high C/I ratio may be related to some prosthetic failures. Unfavorable C/I ratio does not affect biological complications and implant failure.

Vascular Endothelial Growth Factor and Microvessel Density in Periodontitis Patients With and Without Diabetes

BACKGROUND Periodontal disease is one of the major problems encountered in patients with diabetes mellitus (DM), and vascular changes may contribute to periodontitis. Our aim was to investigate vascular endothelial growth factor (VEGF) expression and microvessel density (MVD) in patients with periodontitis with and without DM. METHODS Immunohistochemical detection of VEGF and MVD analysis, evaluated by CD34+ endothelial cell counts, were performed in 66 gingival samples from patients with generalized, severe, chronic periodontitis who were divided into three groups: 22 participants without systemic diseases (controls), 22 participants with type 1 DM (T1DM), and 22 participants with type 2 DM (T2DM). RESULTS In patients with T1DM or T2DM, positive VEGF cells were found to be significantly increased in the epithelium compared to controls. In patients with T1DM, endothelial VEGF expression and MVD were significantly greater than in patients with T2DM and controls. CONCLUSIONS In patients with diabetes, VEGF overexpression plays a primary role in promoting the extravasation of inflammatory cells, suggesting a useful antiangiogenic strategy for periodontitis treatment. The decreased endothelial VEGF expression and MVD found in patients with T2DM may be caused by insulin resistance and endothelial dysfunction, which are often present in patients with T2DM.

Effects of enamel matrix derivative on vascular endothelial growth factor expression and microvessel density in gingival tissues of periodontal pocket: a comparative study.

BACKGROUND Vascular endothelial growth factor (VEGF) stimulates proliferation and migration of endothelial cells, and correlates with inflammatory resolution and periodontal tissue healing. Enamel matrix derivative (EMD) seems to stimulate soft tissue healing. Our aim was to assess if topical EMD application in an instrumented periodontal pocket could affect angiogenesis at the gingival level. METHODS A total of 56 periodontal sites in 28 patients were treated with a single session of comprehensive scaling and root planing under local anesthesia after recording the clinical attachment level (CAL). EMD gel in the test site or only the vehicle propylene glycol alginate in aqueous solution in the control site of the same mouth was applied onto the root surfaces and into the pocket and left in place for 3 minutes. After 48 hours, gingival biopsies were collected for histologic and immunohistochemical analysis for VEGF and CD34 (for microvessel density [MVD] count) antibodies. Statistical comparisons were performed by analysis of variance test. RESULTS Endothelial VEGF expression and MVD were statistically different in the test site compared to the control site. VEGF expression and MVD of the control site were not correlated with CAL, whereas the test site showed high correlations among CAL and endothelial VEGF or MVD. CONCLUSIONS EMD induces proliferation and viability and angiogenesis of human microvascular cells. Recent clinical and histologic studies found EMD to be useful as an adjunct to scaling and root planing in single-rooted teeth. Our findings may help to understand the mechanisms involved in soft tissue healing, through the ability of EMD to increase angiogenesis at periodontal pockets.

Immediate versus early non-occlusal loading of dental implants placed flapless in partially edentulous patients: A 3-year randomized clinical trial

AIM To compare immediate versus early non-occlusal loading of dental implants placed flapless in a 3-year, parallel group, randomized clinical trial. MATERIALS AND METHODS The study was conducted in a private dental clinic between July 2005 and July 2010. Patients 18 years or older were randomized to receive implants for fixed partial dentures in cases of partial edentulism. The test group was represented by immediate non-occlusal implant loading, whereas the control group was represented by early non-occlusal implant loading. The outcome variables were implant failure, complications and radiographic bone level at implant sites 3 years after loading, measured from the implant-abutment junction to the most coronal point of bone-to-implant contact. Randomization was computer-generated with allocation concealment by opaque sequentially numbered sealed envelopes, and the measurer was blinded to group assignment. RESULTS Sixty patients were randomized: 30 to the immediately loaded group and 30 to the early loaded group. Four patients dropped out; however, the data of all patients were included in the analysis. No implant failure occurred. Two complications occurred in the control group and one in the test group. The mean bone level at 3 years was 1.91 mm for test group and 1.59 mm for control group. The adjusted difference in bone level was 0.26 mm (CI 95% -0.08 to 0.59, p = 0.1232). CONCLUSION The null hypothesis of no difference in failure rates, complications and bone level between implants that were loaded immediately or early at 3 years cannot be rejected in this randomized clinical trial.

Ultramorphology of the root surface subsequent to hand-ultrasonic simultaneous instrumentation during non-surgical periodontal treatments. An in vitro study

Objective The purpose of this study was to investigate the ultramorphology of the root surfaces induced by mechanical instrumentation performed using conventional curettes or piezoelectric scalers when used single-handedly or with a combined technique. Material and Methods Thirty single-rooted teeth were selected and divided into 3 groups: Group A, instrumentation with curettes; Group B instrumentation with titanium nitride coated periodontal tip mounted in a piezoelectric handpiece; Group C, combined technique with curette/ultrasonic piezoelectric instrumentation. The specimens were processed and analyzed using confocal and scanning electron microscopy. Differences between the different groups of instrumentation were determined using Pearson’s χ 2 with significance predetermined at α=0.001. Results Periodontal scaling and root planing performed with curettes, ultrasonic or combined instrumentation induced several morphological changes on the root surface. The curettes produced a compact and thick multilayered smear layer, while the morphology of the root surfaces after ultrasonic scaler treatment appeared irregular with few grooves and a thin smear layer. The combination of curette/ultrasonic instrumentation showed exposed root dentin tubules with a surface morphology characterized by the presence of very few grooves and slender remnants of smear layer which only partially covered the root dentin. In some cases, it was also possible to observe areas with exposed collagen fibrils. Conclusion The curette-ultrasonic simultaneous instrumentation may combine the beneficial effects of each instrument in a single technique creating a root surface relatively free from the physical barrier of smear layer and dentin tubules orifices partial occlusion.

Implants placed in sites of previously failed implants: a systematic review.

Purpose:The aim of this study was to systematically review the literature on implant placement in sites of previously failed implants and to assess survival and success rates of the replacement implants to investigate the effectiveness of the procedure. Materials and Methods:MEDLINE and Cochrane Oral Health Group databases were used to identify articles published between 1985 and 2011. Six articles were selected for a total of 334 patients (338 implants). Results:The survival rate ranged from 71% to 100%. The survival rate for implants placed for the second time (third attempt) in the sites of previously failed implants was 83.75%. No studies included in this review reported the cumulative success rate except for the prospective one, which reported a 93.7% success rate. The main limitations of the present systematic review have been the scarce number of patients and implants in the analyzed studies and the lack of large well-designed case-control long-term trials. Conclusions:Survival rates of implants placed in the areas of previously failed implants are low, although they should not discourage clinicians from a second or even a third attempt.

Immunohistochemical correlation between microvessel density and lymphoid infiltrate in radicular cysts.

OBJECTIVE Radicular cysts occur as a result of the immunological response to continuous antigenic stimulation from root canals. We correlated the immunophenotypical composition of the lymphoid infiltrate to the microvessel density expressed by the count of CD34 reactive endothelial cells in radicular cysts. SUBJECTS AND METHODS Thirty-four cases of radicular cysts were evaluated by immunohistochemistry, using antibodies against B- and T-cell antigens (CD20, CD3, CD4, CD8) and against the endothelial cell marker CD34. Statistical analysis was performed. RESULTS In the epithelium, we observed a low amount of lymphoid infiltrate in all 34 radicular cysts, and a strong significant negative correlation between T and B lymphocytes and between T-helper and T-cytotoxic/suppressor lymphocytes. In the cyst capsule, we observed a significant positive correlation between B and T lymphocytes, B and T-cytotoxic/suppressor lymphocytes, T and T-helper lymphocytes and between the number of CD34+ blood vessels and T and T-helper lymphocytes, respectively. We observed a statistically significant correlation between percentage of CD34+ vessels and inflammatory infiltrate grade. CONCLUSIONS Both humoral and cellular immune reactions and neovascularization are likely to occur in the complex events of tissue destruction. The inflammatory infiltrate has an important role in neoangiogenesis and consequently in radicular cysts development and growth.

An in vitro evaluation of heat production during osteotomy preparation for dental implants with compressive osteotomes.

Background:To assess heat production using osteotomes under conditions simulating implant placement in D3, D4 bone. Material and Methods:Implant osteotomes were tested (Winsix, Biosafin, Italy). Site preparations were performed on porcine ribs through a compressive fashion. The ribs were partially immersed in a custom-made water bath/water pump system that maintained the baseline temperature at 36°C. Temperatures generated at different depths (2, 5, and 9 mm) during a series of 25 osteotomies were measured using 3 thermocouples connected to a digital thermometer. Results:The mean temperatures never exceeded 37°C and were all significantly lower than those reported during preparation with standard implant drills. Statistical evaluation of the temperature during implant site preparation showed slight significant variations between the baseline values and those of the different depth preparations. Conclusions:Within the limits of this study, the production of heat during implant preparation using osteotomes shows significant variations at different depths. However, these variations are not clinically relevant because they never increased over the values that negatively affect bone that may jeopardize osseointegration.

A double-blind randomized trial comparing implants with laser-microtextured and machined collar surfaces: Microbiologic and clinical results

PURPOSE The purpose of this study was to compare the clinical outcome of and determine the differences in periodonto-pathogenic microbiota around two types of implant collar surfaces: laser-microtextured (test) vs machined (control). MATERIALS AND METHODS Seventeen patients (11 periodontally healthy, and 6 periodontally compromised) were selected to receive the two different implants, placed randomly, in two edentulous sites. Six months following the surgical placement of the dental implants, subgingival plaque samples were collected using paper points from the peri-implant sulcus and from the sulcus of an adjacent tooth. The presence of five putative periodontal pathogens, namely, Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Treponema denticola, and Tannerella forsythensis, was assessed using real-time polymerized chain reaction (RT-PCR). Peri-implant parameters and intraoral radiographs were recorded up to 1 year after abutment connection. RESULTS In the main population, and in the periodontally compromised subgroup, the total number of periodontal pathogens around test implant sites was lower than control implant sites and adjacent tooth sites, with a statistically significant difference (P < .05). In periodontally healthy patients, the mean probing pocket depth for the test implant was 1.31 ± 0.51 mm, compared with 2.66 ± 0.83 mm for the control implant, while in periodontally compromised patients, it was 1.61 ± 0.58 mm for the test implant, compared with a mean value of 2.84 ± 1.0 mm for the control implant. CONCLUSION Implants with a laser-microtextured collar surface are not more vulnerable to pathogenic microflora colonization than implants with a machined collar surface. In both of the subgroups of patients (periodontally healthy and periodontally compromised), implants with a laser-microtextured collar surface have a better clinical outcome at 1 year of loading, compared with implants with a machined collar surface.