A correlation study of inflammatory cell mobilization in response to subgingival microbial colonization

Atomic force microscopy and scanning electron microscopy evaluation of efficacy of scaling and root planing using magnification: A randomized controlled clinical study

Aim:

A randomized controlled clinical study was undertaken to evaluate the effectiveness of scaling and root planing (SRP) by using Magnifying Loupes (ML) and dental operating microscope (DOM).

Materials and Methods:

A total of 90 human teeth scheduled for extraction from 18 patients aged between 25 and 65 years suffering from generalized chronic severe periodontitis were randomly assigned to three treatment groups. Group 1 consisted SRP performed without using magnification (unaided), Group 2-SRP with ML and Group 3-SRP with DOM. Following extractions, samples were prepared for (i) evaluation of surface topography by atomic force microscopy, (ii) presence of smear layer, debris by scanning electron microscopy (iii) elemental analysis by energy dispersive X-ray analysis. Data was subjected to statistical analysis using analysis of variance, post-hoc (Tukey-HSD) and Chi-square test.

Results:

Statistically significant (P < 0.001) difference was found among the different treatment groups. Group 3 was the best while Group 1 was the least effective technique for SRP. Order of efficacy in terms of the surface was found to be - Palatal < Lingual < Distal ≃ Mesial < Buccal. Efficiency in mandibular to maxillary teeth was found to be significant (P < 0.05), also anterior to posterior teeth (P < 0.05).

Conclusion:

Magnification tools significantly enhance the efficacy of supragingival and subgingival SRP.

Comparative in vitro study of root roughness after instrumentation with ultrasonic and diamond tip sonic scaler

Objective:

The purpose of this study was to evaluate the root surface roughness after instrumentation with hand curette and diamond-coated sonic and universal ultrasonic tips.

Materials and Methods:

Forty root surfaces of human teeth were randomly assigned to four treatment groups: control group (without instrumentation), curette instrumentation, ultrasonic instrumentation with universal tip and sonic instrumentation with diamond-coated tip. Each sample was instrumented with fifteen strokes. Before and after instrumentation, surface roughness was measured. In addition, the root surface topography was examined after treatment under the scanning electron microscope.

Results:

Significant statistical differences (p<0.05) were observed when comparing the control group (0.48±0.07mm) to the treated groups (hand - 1.246±0.279mm, ultrasonic - 1.468±0.177mm and sonic instrumentation - 1.576±0.20mm). The highest roughness was produced by diamond-coated sonic tip and by ultrasonic universal tip (p>0.05).

Conclusion:

The diamond-coated tip with sonic scaler instrumentation and ultrasonic instrumentation produce similar root surface roughness, higher than curette instrumentation.

Subgingival polishing with a teflon-coated sonic scaler insert in comparison to conventional instruments as assessed on extracted teeth (II). Subgingival roughness

AIM

To assess the root surface roughness and topography on extracted teeth using different instruments.

MATERIAL AND METHODS

In the present study, laser profilometry was used to examine the 3-D roughness values Ra and Rz and topography of root surfaces of periodontally-involved teeth instrumented in vivo with curette, conventional ultrasonic device, conventional or teflon-coated sonic scaler insert, or the Periotor instrument (12 teeth per instrument type), and compare these with uninstrumented cementum surfaces.

RESULTS

The roughness values Ra and Rz of the roots treated with the different instruments showed a similar pattern: curettes and the Periotor instrument produced the smoothest surfaces (Ra about 1.5 microm, Rz 30 microm); the 4 other instruments created similar Ra values of approximately 2-3 microm and Rz roughness of about 50-70 microm, which equals the untreated root surface. For Ra, the difference between the curette or the Periotor instrument and the teflon-coated sonic insert or ultrasonic insert was significant, and for Rz, a significant difference was found between the curette or the Periotor instrument and ultrasonic insert. As opposed to surfaces debrided with the Periotor and teflon-coated sonic scaler, it appears that hand instruments markedly reconfigure surfaces.

CONCLUSION

The lowest root-surface roughness values were obtained with hand instruments. The teflon tubing on the sonic scaler insert effected no change of topography or roughness as compared to uninstrumented, control surfaces. However, it must be pointed out that hard-tissue removal was not investigated.

A potential role of an intracellular signaling defect in neutrophil functional abnormalities and promotion of tissue damage in patients with localized juvenile periodontitis

Localized juvenile periodontitis is a destructive form of periodontal inflammatory disease which has its onset at puberty. The etiopathology of the disease is still unclear but neutrophils have been suggested to play a major role both in the production and development of the disorder. About 70% of the patients with localized juvenile periodontitis exhibit neutrophil functional abnormalities, such as decreased chemotaxis and phagocytosis. Interestingly, it has been frequently reported that the same hypoactive cells show an enhanced respiratory burst response and increased adhesion. Several possible mechanisms explaining neutrophil anomalies in localized juvenile periodontitis have been proposed. These include the presence of soluble serum factors capable of modulating neutrophil function, altered cell-surface receptor expression and/or function, and a change in the post-receptor signaling events. Recently, a growing evidence has accumulated showing that the diacylglycerol metabolism could be altered in neutrophils from patients with localized juvenile periodontitis. This change, which may be due to a defect in a major diacylglycerol metabolizing enzyme, diacylglycerol kinase, results in enhanced accumulation of diacylglycerol in activated cells. Because diacylglycerol is an endogenous activator of protein kinase C, the increased and prolonged generation of diacylglycerol could lead to abnormal pattern of protein kinase C-regulated neutrophil functions, explaining the parallel hypo- and hyperactivities.

Inflammatory cell population and bacterial contamination of membranes used for guided tissue regenerative procedures

The purpose of this study was to determine the types of inflammatory cells and bacterial contamination on expanded polytetrafluoroethylene (ePTFE) membranes which might affect new tissue formed by guided tissue regeneration (GTR). Forty periodontal bony defects were treated by the flap procedure, which included the use of an ePTFE membrane. Twelve months after the second surgery, the defect sites were re-evaluated for changes in probing depth and clinical attachment level. The ePTFE membranes were retrieved after 4 to 6 weeks of healing and sectioned serially at 3 microm in a coronal-apical plane. The ePTFE membrane was divided into 3 portions: cervical, middle, and apical, each of which was subdivided into outer, central, and inner segments, providing a total of 9 fields. Cells and bacteria were analyzed by light microscopy for their types: mononuclear cell, erythrocyte, fibroblast, neutrophil, plasma cell, T lymphocyte, B lymphocyte, macrophage, and oral bacteria. Both cells and bacteria decreased in number towards the apical portion and were present even in the central part. Most cells were mononuclear cells. Erythrocytes, fibroblasts, neutrophils, and plasma cells were rarely encountered. Bacteria, most of which were Gram-positive, were observed in almost the same number in the outer and inner parts. The results indicate that numerous inflammatory cells adhered to and invaded the ePTFE membranes accompanied by bacterial contamination and that there was a tendency for a negative correlation between the increment number of bacteria and the gain of clinical attachment level.

The influence of anatomic and iatrogenic root surface characteristics on bacterial colonization and periodontal destruction: a review

PERIODONTITIS IS A MULTIFACTORIAL infectious disease affecting primarily a subset of subjects and a subset of sites. Recent microbiological data have acknowledged that before disease progression can occur, a susceptible host and site are required, in addition to the presence of pathogenic bacteria. This review discusses factors affecting periodontal disease progression and focuses in particular on the influence of anatomic and iatrogenic root surface characteristics. Retrospective studies clearly suggest a strong association between anatomic aberrations and periodontal attachment loss. Cemental tear seems to have the potential to initiate an aseptic, rapid, site-specific periodontal breakdown in a non-infected environment, illustrating the complexity of the attachment loss process. Recent experimental findings, furthermore, demonstrate a significant influence of root surface instrumentation roughness upon subgingival plaque formation and gingival tissue reactions, as well as a significant and positive relationship between subgingival plaque accumulation and inflammatory cell mobilization. These results indicate that subgingivally located irregularities may form stagnant sites or ecological niches which favor both retention and growth of organisms. Such events in addition to the progressive inflammatory changes may critically influence the subgingival environment by turning a stable site into an unstable or active periodontitis site. Thus, local anatomic and iatrogenic root surface characteristics may have a more profound effect on gingival health than previously assumed, particularly on a site level.