Regeneration potential of pulp-dentin complex: Systematic review

Quantitative assessment of transforming growth factor-β1 release from dentin matrix upon conditioning with ethylene diamine tetra-acetate, doxycycline hydrochloride, and propolis: An in vitro study

Background

Transforming growth factor-beta 1 (TGF-β1) is a key morphogen in regenerative endodontics that plays a central role in regulating cellular functions. Various chelating agents have been shown to release this growth factor upon conditioning. The objective of the study was to evaluate TGF-β1 release from the dentin matrix upon conditioning with ethylene diamine tetra-acetate (EDTA), doxycycline hydrochloride, and propolis.

Materials and Methods

Forty-two human 3rd molar teeth were collected and coronal portion of the teeth was sectioned to obtain dentin blocks with dimensions 2 mm × 2 mm × 2 mm. The blocks were then randomly divided into three groups depending on the conditioning agent used; Group 1: 17% EDTA, Group 2: doxycycline hydrochloride (100 mg/mL), and Group 3: propolis (250 μg/mL). Conditioned blocks were placed in 0.5 mL of phosphate buffered saline and incubated for 1 week for quantification.

Results

Highest TGF-β1 release was noted for propolis (0.21 ng/mL), followed by doxycycline hydrochloride (0.18 ng/mL) and 17% EDTA (0.14 ng/mL).

Conclusion

Doxycycline hydrochloride and propolis significantly enhanced the release of TGF-β1 from the dentin matrix compared to EDTA (P < 0.05). No significant difference was observed between doxycycline hydrochloride and propolis (P > 0.05). Doxycycline and propolis can be used as effective alternatives to EDTA during regenerative endodontic procedures.

Regenerative Endodontics Success Factors and their Overall Effectiveness: An Umbrella Review

Introduction

Regenerative endodontics is a developing field of dentistry and aims to recover the physiological and anatomical functions of the tooth for cases of severe dental caries, pulpal pathologies and dental trauma.

Materials and Methods

This umbrella review seeks to discover the scientific evidence on the effectiveness and the factors result in successful regenerative endodontic therapies in teeth with necrotic pulps and with incomplete root development. The study was conducted following the PRISMA Guidelines. There were no restrictions regarding search period. A comprehensive literature search was carried out in EMBASE, LILACS, PubMed, Cochrane, Scopus, and Google Scholar. A quality evaluation was conducted by using AMSTAR-2. A descriptive analysis of the included systematic reviews and meta-analysis were conducted.

Results

Thirteen descriptive systematic reviews and 7 meta-analyses were included. Three articles evidenced low methodological quality according to AMSTAR-2 tool. Overall success rates for the endodontic regeneration procedures ranged from 50% to 98% and the survival rates were between 94% and 100%. Pulp regeneration had a high success rate, evidenced by factors such as the resolution of symptoms, healing, increased root length, dentin thickening and recovery of sensitivity. Follow-up varied from 1 to 48 months for the original studies included in the systematic reviews and meta-analyses.

Conclusions

Endodontic practice offers the clinician a good treatment option in case of necrotic pulp with immature roots such as the endodontic regeneration, that is supported by high and moderate quality scientific literature.

Antimicrobial efficacy of triple antibiotic-loaded chitosan nanoparticles activated with photochemical disinfection: A microbiological and confocal microscopic analysis

Introduction

This in-vitro study comprises Antimicrobial and Confocal Microscopic analysis of the efficacy of Triple Antibiotic and Toluidine Blue (TBO) loaded chitosan nanoparticles (chnp) activated with photodynamic therapy (PDT) against Enterococcus faecalis (Ef).

Methodology

105 single-rooted extracted teeth were decoronated, cleaned and shaped, and incubated with Ef. The roots were randomly divided into three groups: Group I-Control, Group II-Triple Antibiotic Paste (TAP), Group III: Triple antibiotic-loaded chitosan nanoparticles (tachnp), and Group IV: Tachnp and TBO loaded chnp activated with PDT. Ten specimens from all the groups were subjected to antimicrobial analysis and five specimens were observed under the confocal microscope after 24 h and 7 days. Group IV was additionally analyzed after 24 h and 7 days of laser activation.

Results

Group IV C showed the least colony-forming units followed by Group IVB, Group IIIB, Group IVA, and Group IIIA. Group II showed more colony-forming units. On intergroup comparison of mean colony count in control and experimental groups at 24 h and 7 days using one-way ANOVA F test was highly significant P < 0.001. The confocal microscopic images of IV C showed the increased intensity of fluorescent red indicating dead bacteria.

Conclusion

Within the limitations of this study, TAP loaded chitosan nanoparticles activated with PDT showed a significant reduction in colony count.

Mechanisms Involved in Apice Closure of Pulpless Teeth – Literature Review

Background:

Unfinished root formation has always offered challenges in endodontics due to technical difficulties and weakened teeth resistance during the lifetime of an individual. Pulp revascularization therapy appeared as a solution for apical closure and root maturation. The existence of oral stem cells involved in the process associated with traditional resident cells requires adequate blood supply given by induced controlled injury deliberately accomplished into the periapical zone.

Objective:

The aim of this work was to research, through literature review, the main mechanisms involved in the process of apical closure through the technique of pulp revascularization.

Conclusion:

Apice closure in pulpless teeth seems to happen as a result of professional intervention and biological activity. The success rate depends on the role of traditional local immune cells and stem cells associated with adequate blood supply to finish root formation.

Pulp Revascularization: A Literature Review

Reestablishing blood flow and allowing the continuation of root development are some of the objectives of pulp revascularization. This procedure is currently indicated for teeth with incomplete root formation as an alternative to the traditional treatment of apecification, which consists of inserting calcium hydroxide paste into the root canal for a determined time period in order to induce the formation of a calcified barrier. Although it is considered as the most classically employed therapy, the permanence of the paste for long time periods may lead to the weakening of the root due to hygroscopic properties, as well as proteolytic activities of calcium hydroxide. Therefore, there has been a permanent search for alternatives which allow the full development of immature teeth. Revascularization has emerged as such an alternative, and a range of treatment protocols can be found in the scientific literature. The aim of this paper is to accomplish a literature review concerning this issue.

Comparative evaluation of antimicrobial efficacy of triple antibiotic paste and calcium hydroxide using chitosan as carrier against Candida albicans and Enterococcus faecalis: An in vitro study

Aim:

To analyze the sustained release of intracanal medicaments with or without a carrier and testing their antimicrobial efficacy in root canal against Candida albicans and Enterococcus faecalis.

Materials and Methods:

A total of 80 single-rooted anterior teeth were selected, root canal preparation was done, and teeth were divided into two halves and contaminated with C. albicans and E. faecalis, which were further divided into four test groups each according to intracanal medicaments used. Chitosan was used as vehicle for triple antibiotic paste (TAP) and calcium hydroxide and antimicrobial assessment was performed on second and seventh day. Dentine samples were collected after each

Results:

All four medicaments used in this study showed antifungal and antibacterial activity. Group II (TAP + chitosan) and Group III (Ca(OH)₂ + chitosan) had the higher antifungal and antibacterial activity compared with two other groups.

Conclusion:

Combination of TAP + chitosan and Ca(OH)₂ + chitosan produced better results compared with the combination of medicaments with saline.

Proteomics of Human Teeth and Saliva

Teeth have been a focus of interest for many centuries – due to medical problems with them. They are the hardest part of the human body and are composed of three mineralized parts – enamel, dentin and cementum, together with the soft pulp. However, saliva also has a significant impact on tooth quality. Proteomic research of human teeth is now accelerating, and it includes all parts of the tooth. Some methodological problems still need to be overcome in this research field – mainly connected with calcified tissues. This review will provide an overview of the current state of research with focus on the individual parts of the tooth and pellicle layer as well as saliva. These proteomic results can help not only stomatology in terms of early diagnosis, identifying risk factors, and systematic control.

Differentiation of BMMSCs into odontoblast-like cells induced by natural dentine matrix

OBJECTIVE

To assess the odontogenic potential of bone marrow mesenchymal stem cells (BMMSCs) to differentiate into odontoblast-like cells under the morphogenetic influence of dentine matrix as a possible basis for new stem cell-mediated therapeutic approaches to pulp diseases.

DESIGN

BMMSCs were harvested from the whole bone marrow and cells at passages 3-5 were used for subsequent experiments. For in vitro studies, 1×10(4) cells were seeded on the surface of dentine slabs and co-cultured for 2 weeks in 24-well plates, then fixed, decalcified, embedded in paraffin and serial sections were processed for analyses. Haematoxylin-eosin (HE) staining was used for the morphological analysis of BMMSCs on the dentine slabs. The protein expression of dentine sialoprotein (DSP) in co-cultured BMMSCs was detected by immunohistochemical (IHC) staining. For in vivo studies, 5×10(6) cells were collected as cell pellets, seeded onto dentine slices and transplanted into renal capsules for 6 weeks. Histological analyses of harvested tissues were performed as described for the in vitro studies. Total RNA and protein were extracted from harvested tissues and Dspp/DSP expression was investigated by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot, respectively.

RESULTS

After 2 weeks of co-culture with dentine slabs, BMMSCs demonstrated good viability in terms of morphological appearance and some showed polarization and extension of their cytoplasmic processes into dentine tubules with DSP expression. In vivo study demonstrated similar morphological changes and DSP expression in cells adjacent to dentine. RT-PCR and Western blot also demonstrated that the expression of Dspp/DSP in the co-cultured BMMSCs groups was higher than in the control groups.

CONCLUSION

Dentine matrix can signal morphogenic induction of differentiation of BMMSCs into odontoblast-like cells in vivo and in vitro.