METHODS: This study involved life-long residents aged 12 years-old in fluoridated and non-fluoridated areas in Malaysia (n=595). The survey was carried out in 16 public schools by a calibrated examiner, using ICDAS-II criteria. A questionnaire on socio-demographic and oral hygiene practices was self-administered by parents/guardians. Data were analysed using Mann-Whitney U tests and logistic regression.
RESULTS: The overall response rate was 74.4%. Caries prevalence at the dentine level or at the dentine and enamel level was significantly (p⟨0.001) higher among children in the non-fluoridated area (D₁₋₆MFT⟩0 = 82.4%, D₄₋₆MFT⟩0 = 53.5%) than in the fluoridated area (D₁₋₆MFT⟩0 = 68.7%, D₄₋₆MFT⟩0 = 25.5%). Considering only the decayed component of the index, no significant differences were observed between the two areas when the detection threshold was set at enamel caries (D₁₋₃) (p=0.506). However, when the detection criteria were elevated to the level of caries into dentine (D₄₋₆) there were clear differences between the fluoridated and non-fluoridated areas (p=0.006). Exposure to fluoridated water proved a significant predictor for lower caries prevalence in the statistical model. Children whose father and mother had a low monthly income had a significantly higher dentine caries prevalence.
CONCLUSION: Results confirmed existing evidence of the benefit of water fluoridation in caries prevention. Detection criteria set at caries into dentine shows clear differences between fluoridated and non-fluoridated areas. Exposure to fluoridated water and socio-economic status were associated with caries prevalence.
MATERIALS AND METHODS: An estimated 120 human root dentin disks were prepared, sterilized, and inoculated with E. faecalis strain (ATCC 29212) to develop a 3-weeks-old biofilm. The dentin discs were exposed to group I-control group: 5.25% sodium hypochlorite (NaOCl) (n = 20); group II-1% ALX + 5.25% NaOCl (n = 40); group III-1% alexidine (ALX) (n = 40) (Sigma-Aldrich, Mumbai, India); group IV-negative control: saline (n = 20). After exposure, the dentin disks were stained with the fluorescent live/dead dye and evaluated with a confocal scanning electron microscope to calculate the proportion of dead cells. Statistical analysis was done using the Kruskal-Wallis and Mann-Whitney U test (p < 0.05).
RESULTS: The maximum proportion of dead cells were seen in the groups treated with the combination of 1% ALX + 5.25% NaOCl (94.89%) and in the control group 5.25% NaOCl (93.14%). The proportion of dead cells presented in the 1% ALX group (51.79%) and negative control group saline (15.10%) were comparatively less.
CONCLUSION: The antibacterial efficiency of a combination of 1% ALX and 5.25% NaOCl was more effective when compared with 1% ALX alone.
CLINICAL SIGNIFICANCE: Alexidine at 1% could be used as an alternative endodontic irrigant to chlorhexidine, as alexidine does not form any toxic precipitates with sodium hypochlorite. The disinfection regimen comprising a combination of 1% ALX and 5.25% NaOCl is effective in eliminating E. faecalis biofilms.
METHODS: Root canal was prepared using stainless steel K-files™ and ProTaper™ and subjected to manual and ultrasonic irrigation using 6% NaOCl+2% CHX, 6% NaOCl+2% QAS and saline as control. For confocal-microscopy, Raman spectroscopy and SEM analysis before and after treatment, Enterococcus faecalis cultured for 7 days. Raman spectroscopy analysis was done across cut section of gutta percha/sealer-dentine to detect resin infiltration. Indentation of mechanical properties was evaluated using a Berkovich indenter. The contact angle of irrigants and surface free energy were evaluated. Mineralization nodules were detected through Alazarin red after 14 days.
RESULTS: Control biofilms showed dense green colonies. Majority of E. faecalis bacteria were present in biofilm fluoresced red in NaOCl+2% QAS group. There was reduction of 484cm-1 Raman band and its intensity reached lowest with NaOCl+2% QAS. There was an increase in 1350-1420cm-1 intensity in the NaOCl+2% CHX groups. Gradual decrease in 1639cm-1 and 1609cm-1 Raman signal ratios were seen in the resin-depth region of 17μm>, 14.1μm> and 13.2μm for NaOCl+2% QAS, NaOCl+2% CHX and control groups respectively. All obturated groups showed an intact sealer/dentine interface with a few notable differences. 0.771 and 83.5% creep indentation distance for NaOCl+2% QAS ultrasonic groups were observed. Highest proportion of polar component was significantly found in the NaOCl+2% QAS groups which was significantly higher as compared to other groups. Mineralized nodules were increased in NaOCl+2% QAS.
SIGNIFICANCE: Favorable antimicrobial and endodontic profile of the NaOCl+2% QAS solution might suggest clinical use for it for more predictable reduction of intracanal bacteria.
MATERIALS AND METHODS: An experimental adhesive system based on bis-GMA, HEMA and hydrophobic monomer was doped with RF0.125 (RF - Riboflavin) or RF/VE-TPGS (0.25/0.50) and submitted to μTBS evaluation. Resin dentine slabs were prepared and examined using SEM and TEM. Adhesion force was analysed on ends of AFM cantilevers deflection. Quenched peptide assays were performed using fluorescence scanner and wavelengths set to 320nm and 405nm. Cytotoxicity was assessed using human peripheral blood mononuclear cell line. Molecular docking studies were carried out using Schrödinger small-molecule drug discovery suite 2018-2. Data from viable cell results was analyzed using one-way ANOVA. Bond strength values were analysed by two-way ANOVA. Nonparametric results were analyzed using a Kruskal-Wallis test at a 0.05 significance level.
RESULTS: RF/VE-TPGS0.25 groups showed highest bond strength results after 24-h storage in artificial saliva (p<0.05). RF/VE-TPGS0.50 groups showed increased bond strength after 12-months of ageing. RF/VE-TPGS modified adhesives showed appreciable presence of a hybrid layer. Packing fraction indicated solid angle profiles describing well sized density and topology relations for the RF/VE-TPGS adhesives, in particular with the RF/VE-TPGS0.50 specimens. Qualitative analysis of the phenotype of macrophages was prominently CD163+ in the RF/VE-TPGS0.50. Both the compounds showed favourable negative binding energies as expressed in terms of 'XP GScore'.
CONCLUSION: New formulations based on the incorporation of RF/VE-TPGS in universal adhesives may be of significant potential in facilitating penetration, distribution and uptake of riboflavin within the dentine surface.
METHODS: HA having nanorods structure were synthetized using ultrasonication with precipitation method. HA nanorods were characterized by TEM for average-size/shape. Following phosphoric acid demineralization, dentine specimens were treated with HA-nanorods with/without subsequent HIFU exposure for 5 s, 10 s and 20 s then stored in artificial saliva for 1-month. Dentine specimens were characterized using different SEM and Raman spectroscopic techniques. In addition, the biochemical stability and HA-nanorods were examined using ATR-FTIR to observe attachment of nanoparticles. Also, surface nanoindentation properties were evaluated using AFM in tapping-mode.
RESULTS: HA-nanorods displayed well-defined, homogenous plate-like nanostructure. TEM revealed intact collagen-fibrils network structure with high density due to obliteration of interfibrillar spaces with clear evidence of remineralization in combined HA/HIFU treatment. With HA-nanorods treatment collagen-network structure was visible, consisting of fibrils interlaced into a compact pattern with evidence of minerals deposition. AFM investigation revealed clear mineral formation with the increase of HIFU exposure time. Bands associated with inorganic phase dominate well in HIFU exposed specimens with PO stretching within dentine mineral identified at 960 cm-1. Characteristic dentine structure for control and HIFU 20 s specimens is reflected as oscillatory mean Amide-I intensity with measurement giving a precise sinusoidal response of polarization angle β within dentinal tissue. Nanoindentation testing showed a gradual significant increase in elastic-modulus with the increase in HIFU exposure time after 1-month storage. FTIR spectrum of the HIFU exposed dentine displayed bands at 1650 cm-1, 1580 cm-1 and 1510 cm-1 that can be attributed to Amide-I, II and III.
SIGNIFICANCE: The synergetic effect of HIFU exposure on remineralization potential of demineralized dentine-matrix following nano-hydroxyapatite treatment was revealed. This synergetic effect is dependent on HIFU exposure time.
METHODS: Experimental adhesives modified with different fractions of dioctadecyldimethyl ammonium bromide quaternary ammonium and riboflavin (QARF) were formulated. Dentine specimens were bonded to resincomposites with control or the experimental adhesives to be evaluated for bond strength, interfacial morphology, micro-Raman analysis, nano-CT and nano-leakage expression. In addition, the antibacterial and biocompatibilities of the experimental adhesives were investigated. The endogenous proteases activities and their molecular binding-sites were studied.
RESULTS: Modifying the experimental adhesives with QARF did not adversely affect micro-tensile bond strength or the degree of conversion along with the demonstration of anti-proteases and antibacterial abilities with acceptable biocompatibilities. In general, all experimental adhesives demonstrated favourable bond strength with increased and improved values in 1% QARF adhesive at 24 h (39.2 ± 3.0 MPa) and following thermocycling (34.8 ± 4.3 MPa).
SIGNIFICANCE: It is possible to conclude that the use of QARF with defined concentration can maintain bond strength values when an appropriate protocol is used and have contributed in ensuring a significant decrease in microbial growth of biofilms. Incorporation of 1% QARF in the experimental adhesive lead to simultaneous antimicrobial and anti-proteolytic effects with low cytotoxic effects, acceptable bond strength and interfacial morphology.
MATERIALS AND METHODS: Thirty single-rooted mandibular premolars were standardized and prepared using ProTaper rotary files. The specimens were divided into a control group and two experimental groups receiving Diapex and Odontopaste medicament, either filled with iRoot SP or OrthoMTA, for 1 week. Each root was sectioned transversally, and the push-out bond strength and failure modes were evaluated. The data were analyzed using Kruskal Wallis and Mann-Whitney U post hoc test.
RESULTS: There was no significant difference between the bond strength of iRoot SP and OrthoMTA without medicaments and with the prior placement of Diapex (p value > 0.05). However, iRoot SP showed significantly higher bond strength with the prior placement of Odontopaste (p value < 0.05). Also, there was no association between bond strength of OrthoMTA with or without intracanal medicament (p value > 0.05) and between failure mode and root filling materials (p value > 0.05). The prominent failure mode for all groups was cohesive.
CONCLUSION: Prior application of Diapex has no effect on the bond strength of iRoot SP and OrthoMTA. However, Odontopaste improved the bond strength of iRoot SP.
CLINICAL SIGNIFICANCE: Dislodgment resistance of root canal filling from root dentin could be an indicator of the durability and prognosis of endodontic treated teeth.
METHODS: 240 extracted human teeth were sectioned to obtain 6 mm of the middle third of the root. The root canal was enlarged to an internal diameter of 0.9 mm. The specimens were inoculated with E. faecalis for 21 days. Following this, specimens were randomly divided into eight groups (n = 30) according to the intracanal medicament placed: group I: saline, group II: chitosan, group III: propolis100 µg/ml (P100), group IV: propolis 250 µg/ml (P250), group V: chitosan-propolis nanoparticle 100 µg/ml (CPN100), group VI: chitosan-propolis nanoparticle 250 µg/ml (CPN250), group VII: calcium hydroxide(CH) and group VIII: 2% chlorhexidine (CHX) gel. Dentine shavings were collected at 200 and 400 μm depths, and total numbers of CFUs were determined at the end of day one, three and seven. The non-parametric Kruskal Wallis and Mann-Whitney tests were used to compare the differences in reduction of CFUs between all groups and probability values of p dentin treated with CPN250 had less coverage with E. faecalis bacteria similarly, CLSM images also showed higher percentage of dead E. faecalis bacteria with CPN250 than to CPN100.
CONCLUSION: CPN250 was the most effective in reducing E. faecalis colonies on day one, three at both depths and at day seven CPN250 was equally effective as CPN100 and 2% CHX.
METHODS: Root canal preparation was performed using stainless steel K-files™ and F4 size protaper with irrigation protocols of 6% NaOCl + 2% CHX; 3.5% QIS; 2% QIS and sterile saline. Biofilms were prepared using E. faecalis adjusted and allowed to grow for 3 days, treated with irrigants, and allowed to grow for 7 days. AFM was performed and surface free energy calculated. MC3T3 cells were infected with endo irrigant treated E. faecalis biofilms. Raman spectroscopy of biofilms were performed after bacterial re-growth on root dentine and exposed to different irrigation protocols and collagen fibers analysed collagen fibers using TEM. Antimicrobial potency against E. faecalis biofilms and cytoxicity against 3T3 NIH cells were also. Resin penetration and MitoTracker green were also evaluated for sealer penetration and mitochondrial viability. Data were analysed using One-way ANOVA, principal component analysis and post-hoc Fisher's least-significant difference.
RESULTS: Elastic moduli were maintained amongst control (5.5 ± 0.9) and 3.5% QIS (4.4 ± 1.1) specimens with surface free energy higher in QIS specimens. MC3T3 cells showed reduced viability in 6%NaOCl+2%CHX specimens compared to QIS specimens. DNA/purine were expressed in increased intensities in control and 6% NaOCl + 2% CHX specimens with bands around 480-490 cm-1 reduced in QIS specimens. 3.5% QIS specimens showed intact collagen fibrillar network and predominantly dead bacterial cells in confocal microscopy. 3.5% QIS irrigant formed a thin crust-type surface layer with cytoplasmic extensions of 3T3NIH spread over root dentine. Experiments confirmed MitoTracker accumulation in 3.5% treated cells.
SIGNIFICANCE: Novel QIS root canal irrigant achieved optimum antimicrobial protection inside the root canals facilitating a toxic effect against the Enterococcus faecalis biofilm. Root dentine substrates exhibited optimum mechanical properties and there was viability of fibroblastic mitochondria.
METHODS: Dentin slabs were treated with 0.1% riboflavin-5-phosphate modified (powder added slowly while shaking and then sonicated to enhance the dispersion process) Universal Adhesive Scotch Bond and Zipbond™ along with control (non-modified) and experimental adhesives, photoactivated with blue light for 20s. Hydroxyproline (HYP) release was assessed after 1-week storage. Elastic-modulus testing was evaluated using universal testing machine at 24 h. Resin-dentin interfacial morphology was assessed with scanning electron-microscope, after 6-month storage. 0.1% rhodamine dye was added into each adhesive and analyzed using CLSM. Detection of free amino groups was carried out using ninhydrin and considered directly proportional to optical absorbance. Collagen molecular confirmation was determined using spectropolarimeter to evaluate and assess CD spectra. For molecular docking studies with riboflavin (PDB ID file), the binding pocket was selected with larger SiteScore and DScore using Schrodinger PB software. After curing, Raman shifts in Amide regions were obtained at 8 μm levels. Data were analyzed using Two-way analysis of variance (ANOVA, p ≤ 0.05) and Tukey-Kramer multiple comparison post hoc tests.
RESULTS: At baseline, bond strength reduced significantly (p ≤ 0.05) in control specimens. However, at 6 months' storage, UVA Zipbond™ had significantly higher μTBS. Resin was able to diffuse through the porous demineralized dentin creating adequate hybrid layers in both 0.1%RF modified adhesives in CLSM images. In riboflavin groups, hybrid layer and resin tags were more pronounced. The circular dichroism spectrum showed negative peaks for riboflavin adhesive specimens. Best fitted poses adopted by riboflavin compound are docked with MMP-2 and -9 proteases. Amide bands and CH2 peaks followed the trend of being lowest for control UA Scotch bond adhesive specimens and increasing in Amides, proline, and CH2 intensities in 0.1%RF modified adhesive specimens. All 0.1%RF application groups showed statistically significant (p Dentin Eappr of riboflavin application was significantly (p dentin as well as the long-term resin-dentin interfacial integrity and bond strength of universal adhesive to dentin.
Settings and Design: Endodontic treatment aims at disinfection and then obturation of root canal system in to prevent re-infection. Root canal irrigants play a pivotal role in the disinfection process. One of the important properties of an irrigant is the removal of complete smear layer and debris. Smear layer has the potential to protect bacteria within the dentinal tubules; therefore removal may be prudent. Smear layer removal increases the bond strength of resin sealers which results in better apical seal.
Materials and Methods: Forty extracted single-rooted, primary teeth were allocated randomly into four groups of ten each: Group 1 - NaOCl, Group 2 - Nutmeg, Group 3 - Myrobolan, and Group 4 - Tulsi. Samples were stored in sterile saline (0.9% NaCl) and then decoronated at the level of the cementoenamel junction. Working length was determined followed by appropriate irrigation. The roots were split into two halves with a chisel and were stored in 2.5% glutaraldehyde solution for 24 h. After fixation, the samples were dehydrated in ethanol series (70, 90, and 95 and twice at 100%). Each specimen was mounted on Al stub and sputter coated with a 20 nm layer of gold. Samples were then examined using a SEM quantum 60 at magnification of ×2000.
Results: Tulsi demonstrated the most statistically significant results followed by myrobolan and nutmeg extract. All herbal extracts were found to be significantly effective than 2.5% NaOCl.
Conclusion: Tulsi, nutmeg and myrobolan can be effectively used as an irrigant in primary teeth.
METHODOLOGY: Dentin blocks were sterilized and E. faecalis and C. albicans microbial colonies were counted for colony-forming-units against 2%k21, 2%CHX and Ca(OH)2 medicaments. Biofilm colonies after 7 days on dentin were analysed using confocal laser scanning microscopy with live/dead bacterial viability staining. TEM was done to study dentin collagen matrix. Dentin discs from 3rd day and 7th day well plate was used for Raman spectra and observed under fluorescent-microscope. Docking studies were carried out on MMP-2 S1 binding-domain with k21.
RESULTS: There was reduction of E. faecalis/C. albicans when k21, chlorhexidine and calcium hydroxide were used with highest percentage in 2%k21 treated specimens. 2%k21 showed dense and regular collagen network with intact cross-banding and decreased Raman intensity for 2%k21 on 3rd day. NaOCl + k21 showed least adherence, whereas saline groups showed highest adherence of E. faecalis and C. albicans to root-canal dentin. Alizarin red staining of hDPSCs revealed calcium deposition in all groups with significant difference seen amongst 2%k21 groups. MMP-2 ligand binding was seen accurately indicating possible target sites for k21 intervention.
CONCLUSION: 2%k21 can be considered as alternative intracanal medicament.