Bleeding Index and Monocyte Chemoattractant Protein 1 as Gingival Inflammation Parameters after Chemical-Mechanical Retraction Procedure

Determination of Gingival Index and Salivary Proinflammatory Cytokines (Interleukin 6 and Tumour Necrosis Factor α) After Chemical-Mechanical Retraction Procedure

Background and Objectives: The aim of this study was to test the impact of the gingival chemical-mechanical retraction procedure on the value of the gingival index (GI) and salivary concentrations of interleukin 6 (IL-6) and tumour necrosis factor α (TNF-α). The importance of this clinical study is that it provides an exact conclusion regarding the behaviour of the gingival tissue after the application of an impregnated retraction cord in the gingival sulcus of the subjects. Materials and Methods: The research was conducted as a prospective clinical study. The study included 60 subjects divided into two experimental groups, i.e., with and without tooth preparation. Each group was divided into two subgroups according to the retraction agent used. The parameters were measured before, one day after, and three days after the retraction procedure. Results: One day after the application of both gingival retraction agents in both study groups, there was a statistically significant increase in the value of the GI and the salivary concentrations of IL-6 and TNF-α (p < 0.001) compared to the values at the beginning of the study. After 72 h, the values decreased in comparison to those from the second observation period, but they remained statistically significantly higher than the initial values of the study (p < 0.001). Conclusions: The study showed moderate inflammation of the gingival tissue one day after the retraction procedure, which decreased over time. Higher values of the studied parameters were observed with the application of the ferric sulphate-based retraction agent.

Cytomorphometric and Clinical Changes in Gingival Tissue after Subgingival Tooth Preparation-A Pilot Study

Tooth preparation for a metal-ceramic crown with a subgingival finish line can lead to inflammatory changes in the gingival tissue, often accompanied by cell damage. This study aimed to evaluate the clinical signs of inflammation and the cytomorphological status of the gingival tissue before and after tooth preparation. The research included a homogeneous group of 19 patients with an indication for upper canine preparation. Before and after treatment, the gingival and the gingival bleeding indexes were determined, gingival swabs were taken, and direct smears prepared on slides for cytomorphometric analysis. The values of the measured gingival indexes were statistically significantly higher (p < 0.001) after tooth preparation. They decreased over time, which indicated the reversibility of the resulting changes. Cytological examination showed no statistically significant difference between the values of nuclear area, perimeter, Feret diameter, Feret angle, integrated optical density, MinFeret, and roundness, before and after the treatment. Significantly higher values of circularity, integrated optical density, MinFeret (p < 0.05), as well as roundness (p < 0.001) were found after 72 h, compared to those taken 15 min after tooth crown preparation. This study is a pioneering attempt to show gingival changes during fixed prosthodontic treatment and may shed new light on pathogenetic events in prosthodontic patients.

Effects of oral administration of Bifidobacterium animalis subsp. lactis HN019 on the treatment of plaque-induced generalized gingivitis

OBJECTIVES

This double-blind, randomized, placebo-controlled clinical trial evaluated the adjuvant effects of Bifidobacterium lactis HN019 on the treatment of plaque-induced generalized gingivitis.

MATERIALS AND METHODS

Sixty patients were submitted to professional supragingival scaling and prophylaxis. They were randomly assigned to test (probiotic lozenges containing B. lactis HN019, n = 30) or control (placebo lozenges, n = 30) groups. Lozenges were consumed twice a day for 8 weeks. Bleeding on probing (BoP), Gingival Index (GI), Plaque Index (PI), probing depth (PD), and clinical attachment level (CAL) were evaluated at baseline and after 2 and 8 weeks. Gingival crevicular fluid (GCF) was collected at baseline and at 8 weeks for analysis of the inflammatory mediators IL-1β, IL-1α, IL-8, MCP-1, and MIP-1β. Data were statistically analyzed (p < 0.05).

RESULTS

After 8 weeks, both groups showed reduction in the percentage of PI, with no significant difference between groups (p = 0.7423). The test group presented a lower percentage of BoP and a higher percentage of sites with GI ≤ 1 when compared with the control group at the end of the study (p < 0.0001). At 8 weeks, the test group had a greater number of patients without generalized gingivitis than the control group (20 and 11 patients, respectively; p < 0.05). The test group presented significantly lower levels of IL-1α, IL-1β, and MCP-1 in GCF than the control group at the end of the study (p < 0.05).

CONCLUSION

The adjunct use of B. lactis HN019 promotes additional clinical and immunological benefits in the treatment of generalized gingivitis.

CLINICAL RELEVANCE

B. lactis HN019 can be an efficient and side-effect-free adjunct strategy in the treatment of generalized gingivitis.

Local delivery of a CXCR3 antagonist decreases the progression of bone resorption induced by LPS injection in a murine model

OBJECTIVES

This experimental study was carried out to investigate the effects of locally delivered nanoparticles (AMG-487 NP) containing a CXCR3 antagonist in inhibiting the progression of LPS-induced inflammation, osteoclastic activity, and bone resorption on a murine model.

MATERIALS AND METHODS

Thirty, 7-week-old C57BL/6 J male mice were used. Inflammatory bone loss was induced by Porphyromonas gingivalis-lipopolysaccharide (P.g.-LPS) injections between the first and second maxillary molars, bilaterally, twice a week for 6 weeks (n = 20). AMG-487 NP were incorporated into a liposome carrier and locally delivered on sites where P.g.-LPS was injected. Control mice (n = 10) were injected with vehicle only. Experimental groups included (1) control, (2) LPS, and (3) LPS + NP. At the end of 1 and 6 weeks, mice were euthanized, maxillae harvested, fixed, and stored for further analysis.

RESULTS

Volumetric bone loss analysis revealed, at 1 week, an increase in bone loss in the LPS group (47.9%) compared to control (27.4%) and LPS + NP (27.8%) groups. H&E staining demonstrated reduced inflammatory infiltrate in the LPS + NP group compared to LPS group. At 6 weeks, volumetric bone loss increased in all groups; however, treatment with the CXCR3 antagonist (LPS + NP) significantly reduced bone loss compared to the LPS group. CXCR3 antagonist treatment significantly reduced osteoclast numbers when compared to LPS group at 1 and 6 weeks.

CONCLUSIONS

This study showed that local delivery of a CXCR antagonist, via nanoparticles, in a bone resorption model, induced by LPS injection, was effective in reducing inflammation, osteoclast numbers, and bone loss.

CLINICAL RELEVANCE

CXCR3 blockade can be regarded as a novel target for therapeutic intervention of bone loss. It can be a safe and convenient method for periodontitis treatment or prevention applicable in clinical practice.

Biological Response Induced in Primary Human Gingival Fibroblasts upon Exposure to Various Types of Injectable Astringent Retraction Agents

Traditional chemo-mechanical retraction/displacement materials can impact the gingival margin tissues. This study was undertaken to analyze biological responses induced in human gingival fibroblasts (HGFs) upon application of injectable astringent-based agents used in the cordless retraction technique. HGFs were exposed to hemostatic agents (five gels, three pastes, and one foam) based on aluminium chloride, aluminium sulphate and ferric sulphate. Changes in cell viability and proliferation were evaluated using an MTT assay and a BrdU assay. The cytoskeleton structure organization (zyxin and F-actin) was visualized by confocal laser scanning microscopy. Oxidative stress was determined using the Griess Reagent System. The RNA expression levels of antioxidant enzymes were quantified by real-time RT-PCR. The statistical significance was evaluated using Student’s t-test and one-way ANOVA with post-hoc Tukey HSD test. The evaluated agents did not downregulate fibroblast viability or proliferation. No significant cytoskeleton reorganization was observed. Only one agent (Expasyl) induced oxidative stress, demonstrated by the increased level of nitrites. Incubation with the studied agents significantly increased the RNA expression of some antioxidant enzymes (SOD1, SOD3, GPX1). However, no significant influence on the expression of SOD2 and HMOX1 was detected. The injectable forms of chemical retraction agents revealed biocompatibility with HGFs, suggesting their potential clinical usefulness in gingival margin retraction.