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International Endodontic Journal Dec 2022Pulp-dentine complex regeneration via tissue engineering is a developing treatment modality that aims to replace necrotic pulps with newly formed healthy tissue inside... (Review)
Review
BACKGROUND
Pulp-dentine complex regeneration via tissue engineering is a developing treatment modality that aims to replace necrotic pulps with newly formed healthy tissue inside the root canal. Designing and fabricating an appropriate scaffold is a crucial step in such a treatment.
OBJECTIVES
The present study aimed to review recent advances in the design and fabrication of scaffolds for de novo regeneration of pulp-dentine complexes via tissue engineering approaches.
METHODS
A literature search was conducted using PubMed, Europe PMC, Scopus and Google Scholar databases. To highlight bioengineering techniques for de novo regeneration of pulp-dentine complexes, both in vitro and in vivo studies were included, and clinical studies were excluded.
RESULTS
In the present review, four main classes of scaffolds used to engineer pulp-dentine complexes, including bioceramic-based scaffolds, synthetic polymer-based scaffolds, natural polymer-based scaffolds and composite scaffolds, are covered. Additionally, recent advances in the design, fabrication and application of such scaffolds are analysed along with their advantages and limitations. Finally, the importance of vascular network establishment in the success of pulp-dentine complex regeneration and strategies used to create scaffolds to address this challenge are discussed.
DISCUSSION
In the tissue engineering platform, scaffolds provide structural support for cells to adhere and proliferate and also regulate cell differentiation and metabolism. Up to now, considerable progress has been achieved in the field of pulp-dentine complex tissue engineering, and a spectrum of scaffolds ranging from bioceramic-based to naturally derived scaffolds has been fabricated. However, in designing a suitable scaffold for engineering pulp-dentine complexes, a variety of characteristic parameters related to biological, structural, physical and chemical features should be considered.
CONCLUSION
The variety of biomaterials and fabrication techniques provides a great opportunity to address some of the requirements for scaffolds in regenerative endodontics. However, more studies are required to develop an ideal scaffold for use in a clinical setting.
Topics: Tissue Engineering; Tissue Scaffolds; Regeneration; Dental Pulp; Dentin; Polymers
PubMed: 36039729
DOI: 10.1111/iej.13826 -
Scientific Reports Nov 2023The present study aimed to investigate the possible use of a non-instrumentation technique including blue light irradiation for root canal cleaning. Extracted human...
The present study aimed to investigate the possible use of a non-instrumentation technique including blue light irradiation for root canal cleaning. Extracted human single rooted teeth were selected. Nine different groups included distilled water, NaOCl, intra-canal heated NaOCl, and NaOCl + EDTA irrigation after either instrumentation or non-instrumentation, and a laser application group following non-instrumentation technique. The chemical assessment of the root canal dentine was evaluated using energy dispersive spectroscopy (EDS) and Fourier transform infrared (FT-IR) spectroscopy. Surface microstructural analyses were performed by using scanning electron microscopy (SEM). The antimicrobial efficacy of different preparation techniques was evaluated using microbial tests. Light application didn't change the calcium/phosphorus, carbonate/phosphate and amide I/phosphate ratios of the root canal dentin. The root canal dentin preserved its original chemistry and microstructure after light application. The instrumentation decreased the carbonate/phosphate and amide I/phosphate ratios of the root canal dentin regardless of the irrigation solution or technique (p < 0.05). The application of light could not provide antibacterial efficacy to match the NaOCl irrigation. The NaOCl irrigation both in the non-instrumentation and instrumentation groups significantly reduced the number of bacteria (p < 0.05). The use of minimally invasive root canal preparation techniques where the root canal is not instrumented and is disinfected by light followed by obturation with a hydraulic cement sealer reduced the microbial load and preserved the dentin thus may be an attractive treatment option for management of vital teeth needing root canal therapy.
Topics: Humans; Spectroscopy, Fourier Transform Infrared; Dentin; Root Canal Therapy; Phosphates; Carbonates; Amides; Root Canal Irrigants; Edetic Acid; Sodium Hypochlorite; Microscopy, Electron, Scanning
PubMed: 37990070
DOI: 10.1038/s41598-023-47682-9 -
International Journal of Nanomedicine 2021Dentin hypersensitivity (DH) is a common dental clinical condition presented with a short and sharp pain in response to physical and chemical stimuli. Currently no...
BACKGROUND
Dentin hypersensitivity (DH) is a common dental clinical condition presented with a short and sharp pain in response to physical and chemical stimuli. Currently no treatment regimen demonstrates long-lasting efficacy in treating DH, and unesthetic yellow tooth color is a concern to many patients with DH.
AIM
To develop a bi-functional material which can occlude dentinal tubules in-depth and remineralize dentin for long-lasting protection of the dentin-pulp complex from stimuli and bleach the tooth at the same time.
METHODS
A mixture containing CaO, HPO, polyethylene glycol and HO at a specific ratio was mechanically ground using a planetary ball. The mineralizing complex paste was characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Dentin was exposed to the synthesized paste for 8 h and 24 h . The mineralizing property was evaluated using SEM and microhardness tests. Red tea-stained tooth slices were exposed to the synthesized paste for 8 h and 24 h . The bleaching effect was characterized by a spectrophotometer.
RESULTS
The complex paste had very a fine texture, was injectable, and had a gel-like property with 2.6 (mass/volume) % HO concentration. The X-ray diffraction pattern showed that the inorganic phase was mainly monetite (CaHPO). The mineralizing complex paste induced the growth of inorganic crystals on the dentin surface and in-depth occlusion of dentin tubules by up to 80 μm. The regenerated crystals were integrated into the dentin tissue on the dentin surface and the wall of dentinal tubules with a microhardness of up to 126 MPa (versus 137 Mpa for dentin). The paste also bleached the stained dental slices.
CONCLUSION
The mineralizing complex paste is a promising innovative material for efficient DH management by remineralizing dentin and in-depth occlusion of dentin tubules, as well as tooth bleaching.
Topics: Calcium Phosphates; Dentin; Hardness; Humans; Hydrogen Peroxide; Phosphoric Acids; Tooth Bleaching; Tooth Remineralization; X-Ray Diffraction
PubMed: 33442248
DOI: 10.2147/IJN.S287393 -
Clinical Oral Investigations May 2024To assess the growth of a multispecies biofilm on root canal dentin under different radiotherapy regimens.
OBJECTIVES
To assess the growth of a multispecies biofilm on root canal dentin under different radiotherapy regimens.
MATERIALS AND METHODS
Sixty-three human root dentin cylinders were distributed into six groups. In three groups, no biofilm was formed (n = 3): NoRT) non-irradiated dentin; RT55) 55 Gy; and RT70) 70 Gy. In the other three groups (n = 18), a 21-day multispecies biofilm (Enterococcus faecalis, Streptococcus mutans, and Candida albicans) was formed in the canal: NoRT + Bio) non-irradiated + biofilm; RT55 + Bio) 55 Gy + biofilm; and RT70 + Bio) 70 Gy + biofilm. The biofilm was quantified (CFUs/mL). Biofilm microstructure was assessed under SEM. Microbial penetration into dentinal tubules was assessed under CLSM. For the biofilm biomass and dentin microhardness pre- and after biofilm growth assessments, 45 bovine dentin specimens were distributed into three groups (n = 15): NoRT) non-irradiated + biofilm; RT55 + Bio) 55 Gy + biofilm; and RT70 + Bio) 70 Gy + biofilm.
RESULTS
Irradiated specimens (70 Gy) had higher quantity of microorganisms than non-irradiated (p = .010). There was gradual increase in biofilm biomass from non-irradiated to 55 Gy and 70 Gy (p < .001). Irradiated specimens had greater reduction in microhardness after biofilm growth. Irradiated dentin led to the growth of a more complex and irregular biofilm. There was microbial penetration into the dentinal tubules, regardless of the radiation regimen.
CONCLUSION
Radiotherapy increased the number of microorganisms and biofilm biomass and reduced dentin microhardness. Microbial penetration into dentinal tubules was noticeable.
CLINICAL RELEVANCE
Cumulative and potentially irreversible side effects of radiotherapy affect biofilm growth on root dentin. These changes could compromise the success of endodontic treatment in oncological patients undergoing head and neck radiotherapy.
Topics: Biofilms; Dentin; Humans; Dental Pulp Cavity; Candida albicans; Animals; Enterococcus faecalis; Streptococcus mutans; Cattle; Microscopy, Electron, Scanning; Hardness; Microscopy, Confocal; Radiotherapy Dosage
PubMed: 38761225
DOI: 10.1007/s00784-024-05719-x -
Clinical Oral Investigations Jun 2022This study aimed at evaluating the microtensile bond strength (μTBS) and the resin-dentine ultramorphology (24 h and 10 months ageing) of contemporary universal... (Randomized Controlled Trial)
Randomized Controlled Trial
OBJECTIVES
This study aimed at evaluating the microtensile bond strength (μTBS) and the resin-dentine ultramorphology (24 h and 10 months ageing) of contemporary universal adhesives applied in self-etch (SE) or etch-and-rinse (ER) mode.
MATERIALS AND METHODS
Sixty-four sound human molars were collected and randomly allocated in 4 main experimental groups (n = 16) according to the adhesive system employed and subsequently divided into two subgroups depending on their application mode SE or ER (n = 8): ZipBond X (ZBX-SE; ZBX-ER), Prime and Bond Active (PBA-SE; PBA-ER), Clearfil Universal Bond Quick (CBQ-SE; CBQ-ER) or Scotchbond Universal (SCH-SE; SCH-ER). The specimens were cut into sticks with a cross-sectional area of approximately 0.9 mm and subjected to μTBS testing at 24 h or after 10 months of ageing in artificial saliva (AS). Five representative fractured specimens from each group were analysed using field-emission scanning electron microscopy (FE-SEM). Resin-dentine slabs (Ø 0.9mm) from each experimental group were immersed in Rhodamine B and subsequently analysed using confocal microscopy analysis (CLSM). The μTBS results were analysed using a two-way ANOVA and Newman-Keuls multiple-comparison test (α = 0.05).
RESULTS
ZBX, PBA and SCH exhibited greater μTBS values than CQB at 24 h in both SE and ER modes (p < 0.05). CQB showed a significant decrease in μTBS values after ageing both when used in SE and ER mode (p < 0.05). ZBX-ER exhibited no significant differences in the μTBS test after ageing (p > 0.05), while a significant drop in μTBS was seen in SCH-ER and APB-ER after 10-month ageing (p < 0.05). Clear signs of degradation were evident in the resin-dentine interface created with CQB regardless of the application mode or the ageing time. In APB-ER and SCH-ER groups, such signs of degradation were evident after ageing in AS. ZBX showed slight dye infiltration both when used in ER and SE mode.
CONCLUSIONS
The long-term bonding performance of modern universal adhesives is usually influenced by the adhesive strategy employed; self-etching application should be prioritised during dentine bonding. Moreover, the use of shortened bonding protocols may compromise the quality of the resin-dentine interface and the bonding performance of most modern universal adhesives.
CLINICAL RELEVANCE
The use of etch-and-rinse bonding procedures, as well as "shortened" application protocols should be eluded when using modern universal adhesives in dentine. However, new generation universal adhesives based on innovative chemical formulations may probably allow clinicians to achieve long-term bonding performance with such simplified system also when employed in ER mode.
Topics: Acid Etching, Dental; Adhesives; Composite Resins; Dental Bonding; Dental Cements; Dentin; Dentin-Bonding Agents; Humans; Materials Testing; Methacrylates; Resin Cements; Surface Properties; Tensile Strength
PubMed: 35149904
DOI: 10.1007/s00784-022-04402-3 -
The Journal of Adhesive Dentistry Apr 2022To morphologically evaluate the interface between a conventional glass-ionomer cement (GIC) and dentin one day after placement, as well as the changes at the interface...
PURPOSE
To morphologically evaluate the interface between a conventional glass-ionomer cement (GIC) and dentin one day after placement, as well as the changes at the interface after one year of aging/functioning in monkey teeth.
MATERIALS AND METHODS
On the buccal surfaces of seven intact teeth in each of two monkeys, shallow class V cavities were prepared, which were then filled with Fuji IX GP (GC) to provide 1-year in vivo data. A year later, two more teeth in each monkey were similarly prepared and restored for the 1-day in vivo group. The following day, the restored teeth were extracted and the restoration interfaces observed using transmission electron microscopy (TEM). In addition, restorations were similarly placed in two extracted human teeth (control, 1-day in vitro group) and observed a day after placement using TEM.
RESULTS
The 1-day in vivo and in vitro results showed that the GIC appeared to bond to dentin through a demineralized zone similar to the hybrid layer produced by resinous adhesives. However, the interface between GIC and dentin after 1 year in vivo appeared to change over time: many needle-like crystals were detected within the remineralized layer and along the collagen fibrils. Slow diffusion of ions resulted in pores, which filled with mineral crystals and made the pores smaller.
CONCLUSION
The interface between GIC and dentin morphologically changes over time, and recrystallization or remineralization at the interface may occur (1 year in vivo).
Topics: Dental Cements; Dentin; Glass Ionomer Cements; Materials Testing; Microscopy, Electron, Scanning
PubMed: 35416448
DOI: 10.3290/j.jad.b2916453 -
Lasers in Medical Science Oct 2023The aim of this study is to assess the influence of various Er:YAG laser energies on dentin surface micromorphology and dentine-resin shear bond strength (SBS). Eighty...
The aim of this study is to assess the influence of various Er:YAG laser energies on dentin surface micromorphology and dentine-resin shear bond strength (SBS). Eighty dentin specimens were prepared and divided randomly into ten groups: control group (CG), phosphoric acid-etched group (AG), four laser-conditioned groups treated with various pulse energies of 40, 60, 80, and 100 mJ (L40, L60, L80, L100), and four laser-conditioned acid-etched groups (LA40, LA60, LA80, LA100). Two specimens from each group underwent scanning electron microscopy examination, while the remaining six were subjected to the dentin-resin SBS test. Statistical analyses included Welch's analysis of variance (ANOVA), followed by post hoc Tamhane's T2 multiple comparisons test, Pearson's correlation, and Fisher's exact test. Pulse energies of 60, 80, and 100 mJ fully exposed the dentin tubule orifices, although 100 mJ lead to microcracks. Laser-conditioned surfaces exhibited smaller tubule diameters compared to acid-etched surfaces, and tubule diameters positively correlated with dentin-resin SBS. Laser-conditioned groups showed lower SBS values, while laser-conditioned acid-etched groups demonstrated higher SBS values. No significant relationship was observed between dentin surface roughness and SBS. The range of laser energies used for dentin conditioning had limited effects on SBS or failure modes. Laser conditioning with energies ranging from 40 to 100 mJ effectively removes the smear layer from the dentin surface. However, to enhance dentin-resin bond strength, further acid etching of the laser-conditioned surface is necessary.
Topics: Analysis of Variance; Dentin; Lasers, Solid-State; Microscopy, Electron, Scanning; Shear Strength
PubMed: 37878132
DOI: 10.1007/s10103-023-03915-x -
Clinical Oral Investigations Apr 2022The aim of this study was to evaluate the effectiveness of different fiber post removal techniques and to correlate dentinal loss with microcrack formation.
OBJECTIVES
The aim of this study was to evaluate the effectiveness of different fiber post removal techniques and to correlate dentinal loss with microcrack formation.
MATERIALS AND METHODS
Forty-five extracted single-rooted teeth were root canal treated and fiber posts were adhesively luted. Specimens were divided into three groups (n = 15) according to the removal technique: long-shaft round bur (EndoTracer #08, Komet, Lemgo, Germany), SonicFlex Endo (KaVo, Biberach, Germany), DT Post Removal Kit (VDW, Munich, Germany). Roots were scanned before post cementation and after post removal using micro-computed tomography. Dentin loss, residual luting material, working time, and the induction of microcracks were assessed. Statistical analysis was performed by using multiple contrast tests (max-t tests, α = 0.05). Correlations between parameters dentin loss/new microcracks and dentin loss/residual material were calculated using Kendall's tau.
RESULTS
Post removal with SonicFlex Endo resulted in the highest amount of removed dentin with significant differences to the round bur and the DT Post Removal Kit. No technique was found to completely remove the post and luting material. All techniques induced microcracks with the DT Post Removal Kit presenting the highest number of new defects. No correlation between dentin loss and new microcracks was observed. Deviations from the original root canal occurred in all groups, but no perforation was observed.
CONCLUSIONS
All techniques resulted in dentin loss, residual luting material, and the formation of microcracks. However, no correlation between dentin loss and the induction of microcracks was observed.
CLINICAL RELEVANCE
As all techniques resulted in microcrack formation and dentin loss, this study emphasizes the risk of iatrogenic damage due to post removal procedures.
Topics: Dental Pulp Cavity; Dentin; Post and Core Technique; Root Canal Preparation; Tooth Root; X-Ray Microtomography
PubMed: 34893941
DOI: 10.1007/s00784-021-04338-0 -
Stem Cell Reviews and Reports Jun 2021Experimental procedures have been used to monitor cellular responses at the dentin/pulp interface. Aiming to divert from in vivo studies and oversimplified... (Review)
Review
OBJECTIVE
Experimental procedures have been used to monitor cellular responses at the dentin/pulp interface. Aiming to divert from in vivo studies and oversimplified two-dimensional assays, three-dimensional (3D) models have been developed. This review provides an overview of existing literature, regarding 3D in vitro dentin/pulp reconstruction.
MATERIAL & METHODS
PubMed, Scopus, Cochrane Library and Web of Science- were systematically searched for attributes between 1998 and 2020. The search focused on articles on the development of three-dimensional tools for the reconstruction of a dentin/pulp complex under in vitro conditions, which were then screened and qualitatively assessed. Article grouping according to mode of implementation, resulted in five categories: the customised cell perfusion chamber (CPC) (n = 8), the tooth bud model (TBM) (n = 3), the 3D dentin/pulp complex manufactured by tissue engineering (DPC) (n = 6), the entire tooth culture (ETC) (n = 4) and the tooth slice culture model (TSC) (n = 5).
RESULTS
A total of 26 publications, applying nine and eight substances for pulp and dentin representation respectively, were included. Natural materials and dentin components were the most widely utilized. The most diverse category was the DPC, while the CPC group was the test with the highest longevity. The most consistent categories were the ETC and TSC models, while the TBM presented as the most complete de novo approach.
CONCLUSIONS
All studies presented with experimental protocols with potential upgrades. Solving the limitations of each category will provide a complete in vitro testing and monitoring tool of dental responses to exogenous inputs.
CLINICAL RELEVANCE
The 3D dentin/pulp complexes are valid supplementary tools for in vivo studies and clinical testing. Graphical Abstract.
Topics: Dentin; Models, Theoretical; Tissue Engineering; Tooth
PubMed: 33145672
DOI: 10.1007/s12015-020-10069-8 -
Journal of Dental Research Aug 2020Autophagy is an intracellular self-degradation process that is essential for tissue development, cell differentiation, and survival. Nevertheless, the role of autophagy...
Autophagy is an intracellular self-degradation process that is essential for tissue development, cell differentiation, and survival. Nevertheless, the role of autophagy in tooth development has not been definitively identified. The goal of this study was to investigate how autophagy is involved in midkine (MK)-mediated odontoblast-like differentiation, mineralization, and tertiary dentin formation in a mouse tooth pulp exposure model. In vitro studies show that MK and LC3 have similar expression patterns during odontoblast-like cell differentiation. Odontoblast-like cell differentiation is promoted through MK-mediated autophagy, which leads to increased mineralized nodule formation. Subcutaneous transplantation of hydroxyapatite/tricalcium phosphate with rMK-treated human dental pulp cells led to dentin pulp-like tissue formation through MK-mediated autophagy. Furthermore, MK-mediated autophagy induces differentiation of dental pulp cells into odontoblast-like cells that form DSP-positive tertiary dentin in vivo. Our findings may provide 1) novel insight into the role of MK in regulating odontoblast-like differentiation and dentin formation in particular via autophagy and 2) potential application of MK in vital pulp therapy.
Topics: Cell Differentiation; Dental Pulp; Dentin; Dentin, Secondary; Humans; Midkine; Odontoblasts
PubMed: 32442055
DOI: 10.1177/0022034520925427