Immunohistochemical expression of non-collagenous extracellular matrix molecules involved in tertiary dentinogenesis following direct pulp capping: a systematic review

BACKGROUND

Extracellular matrix molecules (ECMM) expression during tertiary dentinogenesis provides useful information for regenerative applications and efficacy of pulp capping materials.

AIM

To identify and review the expression and roles of non-collagenous ECMM after successful direct pulp capping (DPC), following mechanical pulp exposures, via immunohistochemistry (IHC). The study addressed the question of where will successful DPC impact the IHC expression of these molecules.

DATA SOURCES

In vivo animal and human original clinical studies reporting on ECMM in relation to different follow-up periods were screened and evaluated via descriptive analysis. The electronic literature search was carried out in three databases (MEDLINE/PubMed, Web of Science, Scopus), followed by manual screening of relevant journals and cross-referencing, up to December 2018.

STUDY ELIGIBILITY CRITERIA, PARTICIPANTS, AND INTERVENTIONS

Randomized and non-randomized controlled trials, conducted in humans and animals, were selected. Histological evidence for tertiary dentine formation was a prerequisite for IHC evaluation.

STUDY APPRAISAL AND SYNTHESIS METHODS

The methodological quality of the included articles was independently assessed using the Systematic Review Centre for Laboratory animal Experimentation (SYRCLE) and the Cochrane risk of bias tool (RoB 1), respectively.

RESULTS

From a total of 1534 identified studies, 18 were included. Thirteen papers evaluated animal subjects and five studies were carried out on humans. In animals and humans, fibronectin and tenascin expressions were detected in pulp and odontoblast-like cells (OLC); dentine sialoprotein was expressed in both soft and newly-formed mineralized tissue. In animals, bone sialoprotein was early expressed, in association with OLC and predentin; the immunoreactivity for dentine sialophosphoprotein and dentine matrix protein-1 was associated with the OLC and dentine bridge; osteopontin was expressed in OLC, predentine and reparative dentine. A considerable heterogeneity was found in the methodologies of the included studies, as well as interspecies variability of results in terms of time.

CONCLUSIONS AND IMPLICATIONS OF KEY FINDINGS

Within the limited scientific evidence, all non-collagenous ECMM expressions during tertiary dentinogenesis are active and related to soft and hard tissues. There is a shortage of human studies, and future research directions should focus more on them. PROSPERO Protocol: CRD42019121304.

Interleukin-1α and -1β assessment in the gingival crevicular fluid of periodontal patients with chronic hepatitis C

The study assessed whether the increased production of interleukin-1α (IL-1α) and interleukin-1β (IL-1β), as a result of chronic hepatic inflammation, could be the expression of the negative impact on periodontal disease. The study included chronic periodontitis patients who were systemically healthy, chronic periodontitis patients suffering from chronic hepatitis C, as well as control patients, being systemically and periodontally healthy. After periodontal examination and the assessment of certain periodontal parameters, gingival crevicular fluid was collected from all participating patients. By using the enzyme-linked immunosorbent assay method, a quantitative assessment of IL-1α and IL-1β levels was possible. The immunologic results were correlated to the clinical periodontal data. The gingival fluid levels of cytokines were higher for periodontitis patients with chronic hepatitis C than for the systemically healthy periodontitis patients (1.8-fold higher for IL-1α and 2.1-fold higher for IL-1β). In addition, the gingival fluid cytokine levels were significantly higher for the periodontal patients (with/without chronic hepatitis C) than for the control group. Positive correlations were found between gingival fluid IL-1α and IL-1β levels and certain clinical periodontal parameters or the age of the viral hepatitis C diagnosis, in periodontitis patients with chronic hepatitis C. The chronic hepatic inflammation may have an important additional negative impact on the periodontal status, as both inflammatory reactions seem to be promoted by common pro-inflammatory cytokines.

Investigations on the adhesion of new composites for restoring cervical lesions using energy dispersive X-ray analysis and scanning electron microscopy

Restoration of noncarious cervical lesions with resin composites is one of the treatment options, but the retention of the restorations located at the crown-root junction is still a cause of clinical concern. The aim of this study was to evaluate the adhesive properties of three experimental resin composites and two commercial materials used to restore cavities prepared on extracted teeth as well as to determine the relative elemental composition of these materials. We tested the null hypothesis, which considered that the adhesive behaviours of different resin composites did not differ. The microleakage test using tracers showed that all tested materials exhibited some degree of dentinal microleakage, although they all had good dentinal adhesion. The results failed to reject the null hypothesis. The scanning electron microscopy revealed completely adapted adhesive interfaces underneath the restorations along with well-developed hybrid layers depending on the adhesive system. Energy dispersive X-ray analysis analyses showed that the restorative materials have similar chemical compositions, with some differences between the samples from the same material. The results support the implementation of experimental resins in clinical settings.

Optical coherence tomography assessment of gingival epithelium inflammatory status in periodontal - Systemic affected patients

INTRODUCTION

Optical coherence tomography (OCT) is an imaging tool used in various medical fields (ophthalmology, dermatology), which allows the observation of morphological particularities on the surface of tissues or internal constructive details of about 2-3mms in depth. In periodontology, it has been used as an experimental tool for periodontal pocket analysis (depth, calculus deposits) but not for the assessment of periodontal inflammation in the gingival tissues, which has been the subject of our in-vitro study.

MATERIAL AND METHOD

Gingival samples were collected from three types of patients: patients with periodontal disease; patients with periodontal disease and a systemic comorbidity; periodontal and systemic healthy patients. The samples were scanned with an OCT light beam, resulting two-dimensional images of the gingival tissue (full thickness epithelium and partial connective tissue). The images were assessed using dedicated software, which allowed the quantification of pixels on a given segment in the epithelium. The average pixel densities were then calculated for each patient group and statistically analyzed.

RESULTS

The resulted pixel densities were highest for the control group samples, while the lowest pixel densities were found in samples originating from periodontal patients with diabetes mellitus. For the other possible periodontal comorbidity, chronic hepatitis C, image assessment also exhibited lower pixel densities than those of the periodontal group, suggesting that this condition could also have an added effect on the tissular changes induced by periodontal disease.

CONCLUSION

OCT has proven that in an in-vitro environment it can be a useful tool for the assessment of periodontal inflammation in gingival samples of periodontal patients. In terms of inflammatory tissular changes observed by OCT analysis, chronic hepatitis C could be regarded as possible periodontal disease's comorbidity.

How accurate replicates the Thermafil System the morphology of the apical endodontic space? An ex vivo study

AIM

To evaluate the morphology of the root canal in its apical third and the capacity of the Thermafil System to reproduce the entire morphology of the cleaned and shaped root canal.

MATERIALS AND METHODS

Thirty-two roots of periodontally compromised teeth were prepared using the ProTaper System to an apical size 30 and filled with the Thermafil obturation technique and sealer. The roots were surgically amputated and prepared for metallographic evaluation by incremental reductions of 0.5 mm each, starting with the apical foramen. Photomicrographs of each section were taken at a magnification of 500x and 100x. The images were analyzed and processed. The position of the apical foramen with respect to the anatomical apex was identified and marked. Additional morphological details as lateral canals and recesses were also recorded. The cross-sectioned area of the canal and gutta-percha, the total perimeter, the shaped perimeter and the filled perimeter were recorded for each sample and the results were expressed as percentages. Multiple images of successive sections were used to create a 3D reconstruction of the apical anatomy of the tooth. The ANOVA test was performed to assess mean differences between evaluations of perimeters/areas at different levels.

RESULTS

The anatomical apical foramen was found at the tip of the root in 50% of the evaluated samples. In the remaining samples, the foramen was located between 0.5 and 2.5 mm from the centre of the apex. Lateral canals, which opened in accessory foramens, were recorded in 25% of the evaluated samples. Statistical significant differences (p<0.05) were found between different levels of preparation and obturation.

CONCLUSIONS

The complex morphology of the apical third of the root canal is satisfactory microstructurally replicated by the Thermafil System. Moreover, polarized light microscopy and the 3D reconstruction offered a discriminative vision of morphological details as lateral canals, recesses, the gutta-percha and debris.

Computer-assisted photomicrographic evaluation of root canal morphology after removal of the filling material during retreatment

AIM

The purpose of this study was to evaluate the morphology of the apical third of the root canal and the effectiveness of rotary instrumentation for the removal of lateral condensed gutta-percha during endodontic retreatment.

MATERIALS AND METHODS

Thirty roots with canals with regular morphology were prepared to apical size #30 and were filled with gutta-percha/AHPlus using lateral condensation. Digital radiographs of teeth were captured. After two weeks, canals were retreated to size 40 using ProTaper rotary instruments, without solvent. Roots were embedded in resin blocks and reduced incrementally at four different apical levels (at 0.5, 1.0, 1.5 and 2.0 mm from the apical foramen). The sectioned surfaces were observed under a metallographic optical microscope and digital micrographic images were captured and processed. Perimeter covered with root-filling residue was expressed as percentage of total canal perimeter for all specimens.

RESULTS

Residue percentage was greater at 2.00 mm from apical level than at other levels. Most residue of filling material in all specimens was observed at 0.5 and at 2.0 mm from apex. The use of ProTaper instruments allowed the removal of gutta-percha and AHPlus sealer in the apical 2 mm in average 50% of the cases.

CONCLUSIONS

The resulting morphology of the prepared canals allowed root fillings performed with gutta-percha and AHPlus sealer that were efficiently removed by using rotary instruments. More material residue was found adhering to the canal walls in the apical segments of canals. The removal of this residue was enhanced by apical enlargement beyond the diameter of the canal before retreatment.

[The role of smoking in changing essential parameters in body homeostasis]

Smoking, one of the avoidable causes of mortality, is considered a major risk factor for cardiovascular diseases, chronic obstructive pulmonary diseases, and bronchopulmonary cancer. Many studies suggest that nicotine induces vasoconstriction, not only in coronary arteries but also in peripheral vessels, hypertension, pro-atherogenic effects, due to increase of platelet activation and fatty acids concentration, alterations of endothelial-cell shapes, as well as endothelial-cell proliferation. The main affected vascular biochemical parameters are: endothelin-1, cholesterol, triglycerides, lipoproteins, C-reactive protein, nitric oxide, fibrinogen, and uric acid. Cigarette smoke induces inflammation in respiratory epithelium, through local irritation due to release of oxidants, aldehydes, acids, ammonium; impaired ciliar function, and retention of mucus and toxins, followed by infection; carcinogenesis due to oncogene-expression induced by oxidants, aromatic hydrocarbons, and nitrosamines. These effects are induced by alterations of endothelin-1, nitric oxide, IL1, IL6, TNF, and the CYP Enzyme System. Saliva is the first biological fluid encountered by the cigarette smoke. In vitro and in vivo salivary exposure to cigarette smoke has been shown to determine changes of concentrations of lactate dehydrogenase, amylase, and uric acid, in saliva--important factors of the antioxidant salivary system. Such changes may promote occurrence of upper digestive cancers.