Occurrence of Porphyromonas gingivalis, Bacteroides forsythus, and Treponema denticola in Periodontally Healthy and Diseased Subjects as Determined by an ELISA Technique

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/142036/1/jper0018.pd

Biological considerations on the use of zirconia for dental devices.

Zirconium oxide, known as zirconia, is a ceramic material with optimal esthetical and mechanical properties. Zirconia stabilized with yttrium oxide has the best properties for medical uses. A stress on ZrO2 surface creates a crystalline modification that opposes to propagation of cracks. Zirconia core for fixed partial dentures (FPD) on anterior and posterior teeth and on implants are now available. Clinical evaluations after 3 years report good percentage of success for zirconia fixed partial denture. Zirconia biocompatibility was studied in vivo and in vitro by orthopedic research; no adverse responses were reported on insertion of ZrO2 samples in bone or muscle. In vitro experimentation showed absence of mutation and a good viability of cells cultured on this material

Microbiological and biochemical effectiveness of an antiseptic gel on the bacterial contamination of the inner space of dental implants: a 3-month human longitudinal study.

Microbial penetration inside the implant's internal cavity produces a bacterial reservoir that is associated with an area of inflamed connective tissue facing the fixture-abutment junction. The aim of this clinical trial is to evaluate the effectiveness of a 1% chlorhexidine gel on the internal bacterial contamination of implants with screw-retained abutments and on the level of AST secreted in peri-implant crevicular fluid. Twenty-five patients (aged 29 to 58 years) each received one implant. Three months after the end of the restorative treatment, and immediately after a clinical and radiographic examination and the abutment removal, microbiological samples were obtained from the internal part of each fixture and biochemical samples were collected by peri-implant sulci. The patients were then divided into two groups: the control (CG; n=10) and test (TG; n=15) groups. The CG had the abutment screwed into place and the crown cemented without any further intervention. In contrast, before the abutment placement and screw tightening, the TG had the internal part of the fixture filled with a 1% chlorhexidine gel. Three months later, the same clinical, microbiological and biochemical procedures were repeated in both groups. Total bacterial count, specific pathogens and AST activity were detected. The clinical parameters remained stable throughout the study. From baseline to the 3-month examination, the total bacterial counts underwent a significant reduction only in the TG. In contrast, the AST activity showed a significant increase in the CG. The administration of a 1% chlorhexidine gel appears to be an effective method for the reduction of bacterial colonization of the implant cavity and for safeguarding the health status of peri-implant tissue over a 3-month administration period

Root coverage with a coronally positioned flap used in combination with enamel matrix derivative: 18-month clinical evaluation

Background: Ginigival recession can be successfully treated with coronally positioned flaps. Twelve-month data failed to demonstrate that topical application of enamel matrix derivative (EMD) used in combination with the coronally positioned flap enhances clinical outcomes of the surgical technique used alone. This study was designed to examine the effects of EMD combined with the coronally positioned flap over an 18-month postoperative period. Methods: Thirty patients presenting with Miller Class I or 11 gingival recessions on single-rooted teeth participated in this parallel-design clinical study. Six weeks after phase I therapy, recession areas were surgically treated with a coronally positioned flap for root coverage. Teeth in the experimental group received EMD treatment of the exposed root, whereas control teeth did not. Clinical parameters evaluated at baseline and 18 months postoperatively included gingival recession, clinical attachment level, probing depth, and the apico-coronal dimension of the keratinized tissue. Results: Compared to baseline, 18-month measurements showed a significant reduction in probing depth, gain in attachment level, and decrease in gingival recession for control and experimental groups. When the results of the two treatment groups were compared, the experimental group presented with significantly greater root coverage than the control group (2.66 +/- 0.61 mm versus 1.73 +/- 0.70 mm, respectively), more gain in clinical attachment than the control group (2.80 +/- 0.76 mm versus 2.06 +/- 0.70 mm, respectively), and a greater gain in the apico-coronal dimension of the keratinized tissue than the control group (0.13 +/- 0.06 mm versus -0.06 +/- 0.01 mm, respectively). Conclusion: The results of this study indicate that topical application of EMD is beneficial in augmenting the effects of the coronally positioned flap in terms of amount of root coverage, gain in clinical attachment, and in increasing the apicocoronal dimension of the keratinized tissue

Treatment of Supra-Alveolar-Type Defects by a Simplified Papilla Preservation Technique for Access Flap Surgery With or Without Enamel Matrix Proteins

Background: In this study, we compare the effectiveness of enamel matrix derivative (EMD) associated with a simplified papilla preservation flap (SPPF) technique to SPPF alone when surgically treating supra-alveolar-type defects. Methods: Fifty patients, from 54 initially selected, presenting horizontal bone loss around 4 adjacent teeth, were treated by an SPPF technique; 25 participants also received EMD (test group) and 25 patients underwent flap surgery alone (control group). A complete clinical and radiographic examination was performed at baseline and 12 months after treatment. Pre- and post-therapy probing depth (PD), clinical attachment level (CAL), gingival recession (GR), and radiographic bone level (BL) were compared between treatments. Results: After 12 months, PD, CAL, and GR in both groups showed significant differences from baseline (P <0.001). No differences in BL scores were observed within the groups at the 12-month examination. After 1 year, the test group showed significantly (P <0.001) greater PD reduction (3.4 +/- 0.7 mm) and CAL gain (2.8 +/- 0.8 mm) and a smaller GR increase (0.6 +/- 0.4 mm) compared to the control group (PD, 2.2 +/- 0.8 mm; CAL, 1.0 +/- 0.6 mm; GR, 1.2 +/- 0.7 mm.) BL changes did not significantly differ between the experimental groups. Conclusion: The results of this study suggest that combining EMD and SPPF in the treatment of suprabony defects may lead to a greater clinical improvement compared to SPPF alone

Primary stability, insertion torque, and bone density of conical implants with internal hexagon: Is there a relationship?

Between implants and peri-implant bone, there should be a minimum gap, without micromotions over a threshold, which could cause resorption and fibrosis. The higher the implant insertion torque, the higher will be the initial stability. The aim was to evaluate in vitro the correlation between micromotions and insertion torque of implants in bone of different densities. The test was performed on bovine bone of hard, medium, and soft density: 150 implants were used, 10 for each torque (20, 35, 45, 70, and 100 N/cm). Samples were fixed on a loading device. On each sample, we applied a 25-N horizontal force. Insertion torque and micromotions are statistically correlated. In soft bone with an insertion force of 20 and 35 N/cm, the micromotion resulted significantly over the risk threshold, which was not found with an insertion force of 45 and 70 N/cm and in hard and medium bones with any insertion torque. The increase in insertion torque reduces the amount of micromotions between implant and bone. Therefore, the immediate loading may be considered a valid therapeutic choice, even in low-density bone, as long as at least 45 N/cm of insertion torque is reached. Copyright \ua9 2013 by Mutaz B. Habal, MD

Could early rheumatoid arthritis resolve after periodontitis treatment only?

Rheumatoid arthritis (RA) is an immune-mediated polyarthritis; currently no pathogenic agent has been identified as a disease trigger. A patient with RA, presumably caused by periodontal infection, whose remission has been observed after periodontitis treatment in absence of specific RA therapy, is reported here for the first time, to our knowledge. A 61-year-old male patient presented migrant arthritis associated with antibodies against citrullinated protein antigens positivity. The clinical features allowed to make RA diagnosis according to the 2010 European League against Rheumatism/American College of Rheumatology RA classification criteria. X-ray of the second upper molar showed chronic apical periodontitis. After its treatment, arthritis remission has been observed in the absence of specific RA therapy. It has been suggested that periodontitis may have a trigger role in RA pathogenesis. This could be explained by the enzymatic action of Porphyromonas gingivalis, probably leading to break tolerance to collagen. The identification and subsequent treatment of periodontitis should therefore be considered pivotal in RA prophylaxis and management

Clinical and microbiologic effects of subgingival controlled-release delivery of chlorhexidine chip in the treatment of periodontitis: a multicenter study.

Background: The main therapeutic approach for periodontal diseases is mechanical treatment of root surfaces via scaling and root planing (SRP). Multicenter clinical trials have demonstrated that the adjunctive use of a chlorhexidine (CHX) chip is effective in improving clinical results compared to SRP alone. However, some recent studies failed to confirm these clinical results, and conflicting results were reported regarding the effects of the CHX chip on subgingival microflora. The aim of this study was to provide further data on the clinical and microbiologic effects of CHX chips when used as an adjunct to SRP. Methods: A total of 116 systemically healthy individuals with moderate to advanced periodontitis, aged 33 to 65 years, were recruited from the Departments of Periodontology of four Italian universities. For each subject, two experimental sites were chosen that had probing depths (PD) ≥5 mm and bleeding on probing (BOP) and were located in two symmetric quadrants. These two sites were randomized at the split-mouth level, with one receiving SRP treatment alone and the other receiving treatment with SRP plus one CHX chip (SRP + CHX). PD, relative attachment level (RAL), and BOP were evaluated at baseline, prior to any treatment, and after 3 and 6 months. Supragingival plaque and the modified gingival index were evaluated at baseline and after 15 days and 1, 3, and 6 months. Subgingival microbiologic samples were harvested at baseline and after 15 days and 1, 3, and 6 months, cultured for total bacterial counts (TBCs), and investigated by polymerase chain reaction analysis for the identification of eight putative periodontopathogens. Results: When all of the pockets were considered, the PD and RAL were significantly less at 3 and 6 months compared to the baseline scores (P<0.01) for both treatments. Moreover, the PD was reduced in the SRP + CHX treatment group compared to the SRP treatment group at 3 and 6 months, whereas the RAL was similar for both treatments at 3 months and was reduced in the SRP + CHX treatment group at 6 months. The differences in PD reductions between the treatments were 0.30 and 0.55 mm at 3 and 6 months, respectively (P<0.01); for the RAL gain, the differences were 0.28 and 0.64 mm, respectively (P<0.001). The TBCs decreased significantly with both treatments. A similar, although less evident, pattern was noted when only the pockets with an initial PD ≥7 mm were considered. The percentage of sites positive for BOP was similar between the treatments at each time point. At 15 days and 1 month, the TBC for the SRP + CHX treatment group was significantly lower than for the SRP treatment group (P<0.01 and P<0.05, respectively). Over time, both treatments generally reduced the percentages of sites positive for the eight putative periodontopathic bacteria, although greater reductions were seen often for the SRP + CHX treatment group. Conclusions: The adjunctive use of the CHX chip resulted in a significant PD reduction and a clinical attachment gain compared to SRP alone. These results were concomitant with a significant benefit of SRP + CHX treatment on the subgingival microbiota

Microarray expression profiling of human dental pulp from single subject

Introduction: Microarray is a recently developed simultaneous analysis of expression patterns of thousand of genes. The aim of this research was to evaluate the expression profile of human healthy dental pulp in order to find the presence of genes activated and encoding for proteins involved in the physiological process of human dental pulp. We report data obtained by analyzing expression profiles of human tooth pulp from single subjects, using an approach based on the amplification of the total RNA. Methods: Experiments were performed on a high-density array able to analyse about 21,000 oligonucleotide sequences of about 70 bases in duplicate, using an approach based on the amplification of the total RNA from the pulp of a single tooth. Obtained data were analyzed using the S.A.M. system (Significance Analysis of Microarray) and genes were merged according to their molecular functions and biological process by the Onto-Express software. Results: The microarray analysis revealed 362 genes with specific pulp expression. Genes showing significant high expression were classified in genes involved in tooth development, protoncogenes, genes of collagen, DNAse, Metallopeptidases and Growth factors. Conclusion: We report a microarray analysis, carried out by extraction of total RNA from specimens of healthy human dental pulp tissue. This approach represents a powerful tool in the study of human normal and pathological pulp, allowing minimization of the genetic variability due to the pooling of samples from different individuals. © 2008 CIM