Histology and lysosomal cytochemistry of the postsurgically inflamed dental pulp after topical application of steroids. I. Histological study

Betamethasone suppresses the inflammatory response in LPS-stimulated dental pulp cells through inhibition of NF-κB

OBJECTIVE

This study aimed to investigate the anti-inflammatory effect of betamethasone on LPS-stimulated human dental pulp stem cells (DPSCs) and its associated mechanism. The osteo-/odontogenic differentiation and osteoclast effect of betamethasone on DPSCs and stem cells from human exfoliated deciduous teeth (SHED) were evaluated.

DESIGN

The proliferative effect of betamethasone on DPSCs was analyzed using a cholecystokinin octapeptide assay. The anti-inflammatory effect of betamethasone was investigated using quantitative polymerase chain reaction (qPCR) and ELISA. The anti-inflammatory mechanism was explored using qPCR, Western blot, and immunofluorescence staining. The osteo-/odontogenic differentiation and osteoclast effect of betamethasone on DPSCs and SHED were detected by qPCR.

RESULTS

1 μg L^-1 betamethasone was found to have the strongest effect on DPSCs proliferation. The expression of pro-inflammatory cytokines and mediators, as well as prostaglandin E₂ (PGE₂) were significantly decreased following treatment with betamethasone in LPS- stimulated DPSCs. They were also decreased in response to an NF-κB inhibitor, Bay 11-7082. Betamethasone and Bay 11-7082 significantly inhibited the expression of p-p65 and promoted the nuclear exclusion of p65. Gene expression associated with osteo-/odontogenic differentiation was significantly up-regulated in betamethasone and osteogenic media (OM) treated groups. The ratio of the receptor activator of nuclear factor kappa B ligand (RANKL) and osteoprotegerin (OPG) at the mRNA level was suppressed in DPSCs and elevated in SHED.

CONCLUSIONS

Betamethasone has an anti-inflammatory effect on LPS- stimulated DPSCs through a blockade of NF-κB activation and exhibits an osteo-/odonto-inductive effect on DPSCs and SHED. Although betamethasone displays an osteoclast effect on SHED.

Human Pulp Response to Direct Pulp Capping and Miniature Pulpotomy with MTA after Application of Topical Dexamethasone: A Randomized Clinical Trial

Introduction:

The aim of this randomized clinical trial was to compare the histologic pulp tissue response to one-step direct pulp capping (DPC) and miniature pulpotomy (MP) with mineral trioxide aggregate (MTA) after application of dexamethasone in healthy human premolars.

Methods and Materials:

Forty intact premolars from 10 orthodontic patients, were randomly chosen for DPC (n=20) or MP (n=20). In 10 teeth from each group, after exposure of the buccal pulp horn, topical dexamethasone was applied over the pulp. In all teeth the exposed/miniaturely resected pulp tissue was covered with MTA and cavities were restored with glass ionomer. Teeth vitality was evaluated during the next 7, 21, 42, and 60 days. Signs and/or symptoms of irreversible pulpitis or pulp necrosis were considered as failure. According to the orthodontic schedule, after 60 days the teeth were extracted and submitted for histological examination. The Kruskal-Wallis and Fisher’s exact tests were used for statistical analysis of the data (P=0.05).

Results:

Although dexamethasone specimens showed less inflammation, calcified bridge, pulpal blood vasculature, collagen fibers and granulation tissue formation were not significantly different between the groups (P>0.05).

Conclusion:

Topical dexamethasone did not hindered pulp healing but reduced the amount of underlying pulpal tissue inflammation after DPC and MP in healthy human premolars.

Development and validation of RP HPLC method for determination of betamethasone dipropionate in gingival crevicular fluid

Abstract A simple RP HPLC method for quantification of betamethasone dipropionate (BDP) in gingival crevicular fluid (GCF) has been developed and validated. GCF represents a valuable matrix for therapeutic monitoring of drugs used in the treatment of periodontal disease. The proposed method involves single step extraction for sample preparation. The calibration curve for BDP was linear over the concentration range of 0.10-2.00 μg mL⁻¹ (R² = 0.9971). RSD values of intra- and inter-day precision ranged 2.2-4.5 and 1.6-5.7 %, while accuracy values were higher than 96.6 and 97.0 %, respectively. The described method can be successfully applied for determination of betamethasone concentrations in GCF obtained from patients with chronic periodontitis after local treatment with BDP cream 0.5 mg g⁻¹.

Effect of betamethasone on the pulp after topical application to the dentin of rat teeth: vascular aspects of the inflammation

Objective:

This study investigated the pulpal effect of topically applied betamethasone to the dentin of rat molars in the vascular phase of inflammation.

Material and Methods:

Deep cavities were prepared on the occlusal face of the maxillary right and left 1st molars with non-refrigerated inverted-cone steel burs at low speed. Three groups were formed: Group I was composed of right 1st molars; Group II was composed of left 1st molars that received the application of a drop of betamethasone on dentin surface for 5 min; and Group III (control) was composed of right 2nd molars that received no cavity preparation or betamethasone application. Changes in the vascular characteristics of the pulp tissue were checked by calculating the pulp vascular area in relation to its total area and the number of blood vessels per unit area. Data were subjected to ANOVA and Tukey's test (α=0.05).

Results:

Group I presented a significantly larger number of vessels (p<0.05) than Group II. Regarding the vascular/total area ratio (%), Group I presented statistically significantly higher values (p=0.01) than Groups II and III.

Conclusion:

Betamethasone applied on the dentin of rat teeth proved to reduce the vascular phase of pulp inflammation regarding vessel diameter and number of blood vessels.