Obliteration Of Dentinal Tubules Research Articles

The Synergism of Silver and Fluoride: A New Arsenal in Caries Management

AbstractTopical anticaries agents are non‐invasive methods to control and prevent dental caries. SDF is a fluoride‐based agent added to the arsenal of caries prevention tools. It has got a lot of attention since its introduction in the 1970s because of its ability to prevent and arrest caries, as well as its excellent antibacterial and anti‐plaque action. SDF reduces acid production by microorganisms, decreases the Streptococcus mutans count, biofilm formation, increases enamel resistance, and promotes dentinal tubule obliteration when applied to the dental surface. SDF also assists in the remineralization of dentin. A biannual application of 38% SDF has been effective at preventing dentin demineralization. This “silver bullet” can be seen as an alternative for caries prevention in special health care needs children which is minimally invasive and safe. Along with the advantages, there are some disadvantages, and work has been carried out to explore the use of silver nanoparticles (SNP) as anticaries agents to shield the teeth from aesthetic damage caused by Silver diamine fluoride. SNPs are identified to have the potential to prevent and inhibit dental caries while not discoloring demineralized dental enamel. SNPs have a greater surface area for interaction with microorganisms than other particles, making them more effective antimicrobial agents. Fluoride combined with SNP solution has a synergistic effect that promotes enamel remineralization while also acting as a bactericidal agent against cariogenic microorganisms. This review aims to bring out the various advantages and disadvantages related to the use of SDF and SNPs to aid in future research.

Effect of Casearia sylvestrison the obliteration of dentinal tubules and the control of dental sensitivity

The present study evaluated the efficacy of the mineralizing action of Casearia sylvestris ethanolic extract on bovine dentin blocks in its pure form and in dental paste, through scanning electron microscopy. The dentin blocks were immersed in artificial saliva and incubated at 37°C for 7 days. Subsequently, six groups were treated with different test substances and analysed qualitatively and quantitatively at 30 and 60 days. The tests used were Kruskal-Wallis and Dunn's. Shapiro-Wilk and ANOVA. The qualitative analysis at 30 days showed a difference between the groups treated with ethanolic extract and toothpaste. Quantitatively, at 30 days, treatment with ethanolic extract of Casearia showed a greater number of open dentinal tubules. At 60 days, the difference persisted only for the blocks treated with toothpaste. The results obtained indicated that there is a positive relationship between the use of Casearia sylvestris and obliteration of dentinal tubules.

Impact of radiotherapy on the morphological and compositional structure of intra-radicular dentin

Considering the side effects in the oral cavity and dental structures of radiotherapy (RDT) for head and neck cancer, this study aimed to evaluate the effects of RDT on the root dentin concerning the obliteration of dentinal tubules, the inorganic composition of intra-radicular dentin, and the integrity of collagen fibers. Thirty human canines were selected from a biobank and randomly divided into two groups (n=15). The samples were sectioned buccolingually, and a hemisection was used for structural analysis by scanning electron microscopy (SEM) and energy-dispersive X-ray spectrometer (EDS). Low-vacuum SEM images were obtained at 2000-x magnification to observe the obliteration of the dentinal tubules. Moreover, compositional evaluation was performed using EDS. After RDT, the SEM and EDS analyses were repeated using the same methodology. RDT was applied fractionally at 2 Gy per day, 5 days per week, for 7 weeks, resulting in a total dose of 70 Gy. The collagen integrity of the irradiated and non-irradiated samples was analyzed using Masson's trichrome and picrosirius red staining polarization microscopy. Samples subjected to RDT exhibited dentinal tubule obliteration (p < 0.001); low integrity of type I and III collagen fibers (p < 0.05); compositional reduction of calcium (p = 0.012), phosphorus (p = 0.001), and magnesium (p < 0.001); an increased Ca/P ratio (p < 0.001). RDT affects the structure of dentinal tubules, the inorganic composition of intra-radicular dentin, and the collagen fiber integrity in the root dentin, which may interfere with the effectiveness and durability of dental procedures.

Comparative Evaluation of the Effectiveness of Three Commercially Available Desensitizing Mouthwash on Dentinal Tubule Occlusion: An In Vitro Scanning Electron Microscopic Study.

To compare and evaluate the effectiveness of three commercially available desensitizing mouthwashes on dentinal tubule occlusion in vitro using a scanning electron microscope (SEM). Twenty-seven premolar maxillary teeth were collected and cleaned to remove debris and tissue using an ultrasonic scaler. Enamel was removed with the help of a high-speed plain cut tungsten carbide fissure bur under continuous water spray. Dentinal discs measuring 5 mm × 5 mm × 3 mm were prepared from the coronal region of the extracted teeth using a double-sided carborundum disc and straight micromotor handpiece. Using carborundum paper, the discs were polished and washed with distilled water. The discs were etched using 37% phosphoric acid to remove any smear layer that was caused by the grinding process and to simulate dentinal hypersensitivity by opening the dentinal tubules. The specimens were again washed and stored in distilled water until use. Samples were then randomly allocated into Group A: calcium sodium phosphosilicate mouthwash, Group B: potassium nitrate mouthwash, and Group C: dipotassium oxalate monohydrate mouthwash. The specimens were immersed in a test tube filled with the respective mouthwash and vigorously shaken for 60 s for simulating the natural mouth rinsing action. This procedure was repeated for 7 days, twice daily. To compare and assess the proportion of dentinal tubule occlusion, all the samples were processed and examined under an SEM. The efficacy of the mouthwash on the obliteration of dentinal tubules was compared using the Kruskal-Walis analysis of variance test followed by the post hoc Mann-Whitney U test for pairwise comparison. Group A showed completely occluded tubules in 5 (55.6) and mostly occluded tubules in 4 (44.4). Group B showed mostly occluded in 4 samples (44.4) and partially occluded in 5 samples (55.6) and Group C showed completely occluded tubules in 3 samples (33.3) and mostly occluded tubules in 6 samples (66.7). A P value of 0.05 or less is regarded as statistically significant. *P ≤ 0.05 is statistically significant. Between Group A and Group B as well as between Group B and Group C, there was a statistically significant difference. However, a statistically significant difference between Group A and Group C does not exist. The calcium sodium phosphosilicate group was shown to have the most occlusion of the dentinal tubule, followed by dipotassium oxalate monohydrate and potassium nitrate group.

Experimental pastes containing niobophosphate and 45S5 bioactive glasses for treatment of dentin hypersensitivity: dentin permeability and tubule obliteration.

This study tested the ability of bioactive pastes containing niobophosphate and 45S5 glasses to reduce dentin permeability and to obliterate dentinal tubules, as a mean of reducing human dentin hypersensitivity. Experimental pastes with concentrations of 10, 20, and 30 wt% of two bioactive glasses (45S5 or niobophosphate [NbG]) were formulated. A paste without bioactive glass (placebo) and a commercial paste (Nano P, FGM) were used as controls. Forty dentin disc specimens were obtained from caries-free extracted third human molars and divided in 8 groups (n = 5). Percentage of permeability (%Lp) was assessed in a dental permeability machine considering hydraulic conductance, immediately after pastes application and at day 7, day 14, and day 21. The precipitates formed on the surface of the dentin discs (and dentinal tubules) were analyzed by SEM/EDS and micro-Raman spectra. Data of dentin permeability (%) 2-way repeated-measures (ANOVA) and Holm-Sidak post-tests (α = 0.05). Dentinal tubule obliteration was visually (and elemental) evaluated and descriptively reported. The experimental bioactive glass pastes containing NbG and 45S5, regardless of the concentration, reduced dentin permeability in comparison with pastes without bioactive glasses (P < 0.05). The formulated placebo and commercial paste did not reduce permeability over time (P < 0.05). SEM/EDS and micro-Raman analyses showed that both type of bioactive pastes (NbG or 45S5-based) presented mineral precipitates obliterating the dentinal tubules at day 21. NbG seems to offer a better initial effect than 45S5, while at 21 days there is no difference between both glasses. Experimental bioactive pastes containing NbG and 45S5 (at concentrations of 10%, 20%, or 30%) have potential to reduce dentin permeability (over time) in comparison with pastes without bioactive glasses; and this occurs on behalf of obliteration of dentinal tubules by microparticle and precipitate formation. Bioactive pastes containing NbG and 45S5 may benefit patients presenting dentin hypersensitivity, because these pastes can start acting fast after application and maintain their action up to 21 days.

Effect of Diode Laser versus a Combination of Sodium Trimetaphosphate with Polyacrylic Acid on Obliteration of Dentinal Tubules: An In Vitro Study

BACKGROUND: Irradiation with diode laser and biomimetic remineralization are important methods in the treatment of hypersensitivity and dentin remineralization. AIM: The aim of the study was evaluation of the effect of diode laser versus the effect of sodium trimetaphosphate (STMP) with polyacrylic acid (PAA) on obliteration of dentinal tubules (DT). MATERIALS AND METHODS: Sixty dentin discs with a thickness of 2 mm were prepared and conditioned with EDTA for 15 s. Then, all dentin discs were divided into three main groups (20 discs each) according to the treatment method; control, diode laser treated, and STMP with PAA group (biomimetic group). Each group was subdivided into four subgroups (five discs each) according to the storage time; 2 h (To), 1 month (T1), 2 months (T2), and 3 months (T3), respectively. All samples were prepared to be analyzed after each time interval using environmental scanning electron microscope (ESEM). Comparison of differences of DT obliteration percentage made on each group before and after the treatment were performed using computer-assisted digital image analysis. RESULTS: Control group showed the least DT obliteration percentage, the samples of laser group recorded statistically significant increase in DT obliteration percentage at To in comparison to the biomimetic group. Meanwhile, at T1, there was no statistically significant difference between both laser and biomimetic groups. However, statistically significant decrease was recorded in laser group at T2 and T3, respectively. CONCLUSION: Irradiation with diode laser and biomimetic remineralization using PAA with STMP are a promising methods to obliterate opened DT effectively.

Obliteration of Dentinal Tubules by Desensitizing Agents Based on Silver Fluoride/Potassium Iodide or Pre-Reacted Glass Particles: An in Vitro Study

Obliteration of Dentinal Tubules by Desensitizing Agents Based on Silver Fluoride/Potassium Iodide or Pre-Reacted Glass Particles: An in Vitro Study

Effects of Remineralizing Agents Based on Calcium Phosphate, Sodium Phosphate, or Sodium Fluoride on Eroded Cervical Dentin.

To evaluate the effect of remineralizing agents on collagen matrix pattern, precipitate formation, and dentinal tubule obliteration in eroded cervical dentin. One hundred bovine cervical dentin specimens were previously eroded (0.6% hydrochloric acid, pH 2.3, 5 minutes) and then randomized into five groups (n=20): G1, control (without treatment); G2, Desensibilize Nano P (FGM); G3, MI Paste Plus (Recaldent); G4, Regenerate (NR-5); and G5, Desensibilize KF 2% (FGM). These treatments were applied in four sessions with 7-day intervals. During this period, the samples were subjected to an erosive challenge with orange juice (pH 3.8, 5 minutes). The specimens were analyzed by polarized light microscopy with picrosirius red staining, scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX). The G3 showed a higher concentration of type I collagen than G2 and G5 (p<0.05). The G3 showed greater formation of surface precipitates than that of G1 and G5 (p<0.05). In addition, G4 and G5 showed a greater number of open dentinal tubules than that of G3 (p<0.05). Calcium phosphate-based remineralizing agents have shown to be a promising alternative treatment for preventing deleterious effects on the eroded dentin collagen matrix. In addition, they promoted precipitate formation and dentinal tubule obliteration on the eroded dentin.

Novel Management of Hypersensitive Dentin Using Propolis-based Herbal Desensitizing Agents: An In Vitro Scanning Electron Microscopic Study

The objective of this in vitro study was to assess the efficacy of novel propolis-based varnish against the two conventional varnishes on quantitative and qualitative assessments of occlusion of dentin tubules and resistance to erosive and abrasive wears employing scanning electron microscope (SEM). Thirty human premolars free from caries extracted due to orthodontic reasons were included in the study. Experimental group was done based on treatment received and divided into three groups. Group A: ClinProXT Varnish (n = 10), Group B: MI Varnish (n = 10), and Group C: Propolis Varnish (n = 10) were applied. Teeth were cleaned and decoronation of crown was done with dentin disks. Dentin specimens of dimension 4 × 4 × 2 mm were prepared and subjected to finishing and polishing. The sample specimens were submersed in EDTA solution for a period of five minutes to open up the dentinal tubules. This was followed by treatment with varnishes and subjection to acidic-abrasive challenge. The specimens were analyzed with an image analyzer connected to SEM for the verification of the number of opened dentin tubules. The parameter assessed in SEM includes size, topography and surface characteristics of dentinal tubule were assessed. The obliteration potential of dentinal tubules was assessed with SEM images. Additionally, the dentin surface loss and resistance to acidic and abrasive wear were also evaluated with SEM. Data were analyzed with two-way analysis of variance (ANOVA) with post hoc Tukey's test. MI Varnish caused higher obliteration of dentin tubules followed by ClinproXT Varnish. Propolis Varnish showed the least obliteration of dentinal tubules among tested experimental groups. After acidic-abrasive challenge, Propolis Varnish was found to be more efficient with less material loss among the experimental groups tested. There was an insignificant difference among the MI Varnish and ClinProXT Varnish groups. Simulation of hypersensitive lesions mimicking the clinical scenario was a challenging task in this in vitro study. All varnishes tested in the study had good efficacy in the management of dentin hypersensitivity (DH). Propolis-based varnish had good resistance to material loss after subjection to acidic-abrasive challenge among the tested materials. The casein phosphopeptide (CPP)-amorphous calcium phosphate (ACP)-based MI Varnish had good efficacy to obliterate the dentinal tubules among the tested materials. It was prudent to select the varnishes with good long-term efficacy to survive in the clinical scenario which still remains a challenging task for the clinicians. The stability of the varnish plays a vital role in maintenance of its long-term efficacy. The chemical nature along with the ability of the material to interact with the substrate plays a major role in management of DH.

Consequences of chemical residue formation during potentiation of final irrigation

Seeking to increase the efficiency of endodontic irrigation, the association of different solutions as final irrigant has been investigated, such as sodium hypochlorite with chlorhexidine. The literature shows that the combination of these substances leads to the formation of a brownish precipitate, but does not reveal measurements of the intensity of this precipitate and its consequences. Aim: The present study aimed to evaluate the change in dentin color and the obliteration of the dentinal tubules after the association of sodium hypochlorite (NaOCl) with chlorhexidine (CHX) in the final irrigation. Methods: Fifty sterile human lower premolars were prepared with a ProDesign R 35.05 files and divided into 6 groups. Four different NaOCl concentrations (0.5%; 1%, 2.5% and 5.25%) associated with 2% CHX were tested, in addition to 2 control groups, using only 2.5% NaOCl and 2% CHX, respectively. After the final irrigation protocol, the dentin color change was evaluated by spectrophotometry immediately and after 24 hours, and the dentinal tubule obliteration was assessed by scanning electron microscopy. Results: It was possible to verify that regardless the NaOCl concentration used when associated with CHX, a chemical residue was formed, with consequent dentin pigmentation and tubular obstruction. There was a trend towards increased dentin pigmentation and tubular obstruction due to the deposition of the chemical residue formed by this association. Conclusion: It can be concluded that all concentrations of NaOCl associated with CHX caused color changes and tubular obstruction, being proportional to the concentration of NaOCl used.

Hydraulic conductance of dentin after treatment with fluoride toothpaste containing sodium trimetaphosphate microparticles or nanoparticles.

To evaluate the hydraulic conductance of dentin after treatment with fluoride toothpastes containing sodium trimetaphosphate microparticles (TMPmicro) or nanoparticles (TMPnano). The dentinal tubules of bovine dentin blocks (4 × 4 × 1 mm) were unobstructed for determination of the maximum hydraulic conductance of the dentin. The dentin blocks were randomized into four groups (n = 15/group) of toothpastes (placebo, 1100 ppm F, and 1100 with 3% TMPmicro or 3% TMPnano) which were applied for 7 days (2×/day) using a brushing machine. The dentin surface (5/group) was analyzed by scanning electron microscopy. The hydraulic conductance post-treatment was measured in the other ten blocks. Thereafter, the same blocks were immersed in citric acid (pH 3.2) for 1 min, and the conductance was determined again. The data were submitted to 2-way ANOVA repeated measures, followed by the Student-Newman-Keuls test (p < 0.05). The percentage conductance reduction post-treatment for the groups were placebo = 1100 ppm F < 1100 TMPnano < 1100 TMPmicro (p < 0.001). After acid attack, the percentage reduction was placebo < 1100 ppm F < 1100 TMPnano < 1100 TMPmicro (p < 0.001). The toothpastes containing TMP showed the highest obliteration of dentinal tubules. The addition of TMPmicro to fluoride toothpaste produced a greater reduction in hydraulic conductance when compared with 1100 ppm F toothpaste. The increased capacity of toothpastes containing TMP to reduce hydraulic conductance indicates their potential to reduce symptoms of dentinal hypersensitivity.

Effect of Dentin Conditioning and Erosive Coca Cola Challenge on the Micro-shear Bond Strength and SEM Evaluation of Resin-Modified Glass-Ionomer Cement- in vitro study

Objective: This study was designed to evaluate the role of an erosive beverage, Coca cola, on the microshear bond strength of a nano-fill resin modified glass-ionomer cement to dentin, after different conditioning protocols, no conditioning, GC conditioner and KN primer. Materials and Methods: The occlusal enamel of forty two third molar teeth was removed, exposing the coronal dentin. Thirty prepared teeth were randomly divided into three main groups (n=10). Group 1, flat dentin surface was left unconditioned (control). Group 2, GC cavity conditioner was applied. Group 3, Ketac Nano Primer was applied. Three pieces were cut from a polyethylene micro-bore tygon tube, for each specimen. KN resin modified glass ionomer cement was applied. Each group was further distributed into two subgroups (n=5). Subgroup i, teeth were immersed in artificial saliva (control). Subgroup ii, teeth were subjected to Coca Cola pH cycles. Each specimen was stressed in shear using a load cell of 5 KN at a crosshead speed of 0.5 mm/min. The remaining 12 teeth were divided according to the previously mentioned grouping system, and observed using SEM. Results: The data collected for µSBS were subjected to two-way ANOVA test, followed by Tukey’s post hoc test. Considering the dentin conditioning factor, with storage in artificial saliva; the control group revealed the least µSBS values, followed by the group conditioned with KNP and GC conditioning, respectively. Control group posses a significant decrease in the µSBS compared to either GC or KNP groups. With Coke pH cycling; the control group revealed the least µSBS values, followed by KNP and GC conditioning, respectively. All the tested groups are significantly different from each other Considering the erosive pH cycling factor, all the teeth revealed significant decrease in the µSBS values, when exposed to erosive Coke pH cycling. Most failure modes are adhesive, followed by mixed failures. The SEM examination showed a filler‑free zone in the conditioned groups, with the greatest thickness with KNP. Cylindrical shaped resin tags, were observed when dentin is conditioned with KNP, whereas budding configuration is formed with GC conditioner. Smear layer has been completely removed with GC conditioner. Dentin conditioning with KNP revealed partial removal of smear layer with partial obliteration of dentinal tubules, while smear layer remains unaffected in case of control group. In groups stored in AS, there is intimate adaptation between the RMGIC and dentin, whereas the groups subjected to Coke erosive cycles showed variable degrees of separation at the RMGIC/dentin interface. Conclusions: Dentin conditioning before RMGIC application is an essential step to improve bonding ability to dentin. Since Coca cola beverage revealed a deteriorating effect on bonding of RMGICs, evaluation of different acidic foodstuffs, acidic drinks and mouthwashes on the bonding efficiency of different types of glass-ionomer cements is required.

Effect of photo-polymerized versus chemical cured glass ionomer based desensitizing agents on patency of dentinal tubules

Background: The diagnosis of dentin hypersensitivity is done by exclusion. Yet no universally accepted gold-standard treatment, which reliably relieves the pain of dental hypersensitivity in the long term and satisfy both the dentist and the patient, was found. Objective: to compare the effect of photo polymerized versus chemical cured glass ionomer based desensitizing agents in respect to: a) Their ability to occlude the dentinal tubules. b)Their depth of penetration inside the dentinal tubules. Materials and Methods: A total of 20 permenant molars were selected, promximal enamel was removed, EDTA gel (17%) was applied for three min. The prepared fourty surfaces were divided into two groups. Half of both surfaces received different desensitizing agent while the other half was left untreated as a control. Each group was divided into four subgroups, the first subgroup faced abrasion challenge, the second faced thermocycling, third faced both abrasion and thermocycling and the last was left as a control group. An ESEM at 2000 magnification was used to observe the patent dentinal tubules, and a digital Analysis program was used to evaluate the patency. Results: showed that the percent of obliteration of dentinal tubules when the samples faced abrasion only was higher in CGI than RMGI, same result when the samples face termocycling only it was still higher in CGI than RMGI. Whereas there was no statistical significance when the samples received both abrasion and thermocycling. Conclusion: 1- The abrasion resistance and the ability of CGI to withstand thermocycling makes it better in occluding dentinal tubules rather than RMGI. 2- Although the resinous component of RMGI allows better penetration inside the tubules, yet the lower abrasion resistance and poor resistance to thermocycling made the material inferior in maintaining an efficient dentinal tubules seal.

Evaluation of dentin desensitization protocols on the dentinal surface and their effects on the dentin bond interface

ObjectivesTo evaluate the effect of desensitizing agent containing calcium phosphate nanoparticles on the bond strength of etch-and-rinse adhesive system (Scotchbond Multi-Purpose), presence of precipitate, dentinal tubule obliteration and hybrid layer formation in dentin in comparison with potassium nitrate plus sodium fluoride or strontium chloride compounds. Methods150 bovine incisors were treated with (n = 10): G1, Desensibilize Nano P (Ca3(PO4)2+5%KNO3+0.9%NaF); G2, Desensibilize (10%SrCl2+5%KNO3); G3, Desensibilize KF2% (5%KNO3+0.2%NaF); G4, Ultra EZ (3%KNO3+0.25%NaF) and G5, no treated (control). Scanning electron microscopy was used to assess the incidence of precipitates (500×) and obliterated dentinal tubule counts (1.000×). The adhesive system was used after all desensitization treatments. The bond strength (n = 40) and the fracture pattern were evaluated. Confocal laser microscopy was used to quantify the hybrid layer formation in dentin. ResultsG1 and G2 presented higher adhesive system bond strength (MPa) than G4 and G5, however no significant differences were observed in comparison with G3. Cohesive fracture was frequently found: G1 (58.5%), G2 (51.3%) and G3 (43.8%). G1 showed the highest incidence of precipitates and the highest number of blocked dentinal tubules. G1 and G2 presented similar hybrid layer formation and the highest hybrid layer formation values. ConclusionsDesensibilize Nano P (G1) favored the bond strength of the adhesive system to dentin, increased the precipitation of residues, obliteration of dentinal tubules, and hybrid layer formation in comparison with other agents. Clinical relevanceDesensitizers promote dentin obliteration, however, may affect dentin bonding.

Dentinal tubule obliteration using toothpastes containing sodium trimetaphosphate microparticles or nanoparticles.

This in vitro study evaluated the effect of microparticles (TMPmicro) or nanoparticles (TMPnano) TMP associated with fluoride (F) in toothpaste formulations on the obliteration of dentinal tubules (DT). The dentinal tubules of bovine dentin blocks were unobstructed by immersion in 37% phosphoric acid solution. Blocks (n = 20/group) underwent mechanical brushing (2×/day) during 7days with toothpastes: placebo, 1100ppm F, and 1100 with 3% TMPmicro or 3% TMPnano. After that, ten blocks of each group were immersed in citric acid (pH 3.2) for 1min. The number, diameter and area of unobstructed DT, atomic % of chemical elements from precipitates, and the mineral concentration were quantified. Data were submitted to two-way ANOVA, followed by Student-Newman-Keuls test (P < 0.05). Toothpastes containing TMPmicro and TMPnano promoted greater obliteration of DT and greater mineral concentration compared to other groups (P < 0.05). Placebo and 1100ppm F group presented similar obliteration but 1100ppm F group promoted higher mineral concentration. Higher Ca/P ratios were observed in groups treated with TMP; the acid challenge reduced Ca/P ratio for all groups. The atomic % of C and N was significantly lower for TMP toothpastes before acid challenge, but increased afterwards. It was concluded that the addition of TMPmicro or TMPnano to F toothpastes produced greater obliteration of dentinal tubules and higher mineral concentration when compared with 1100ppm F. By the addition of TMP, fluoride toothpastes may occlude the dentinal tubules, with potential to reduce dentin hypersensitivity.

Evaluation of ex vivo effectiveness of commercial desensitizing dentifrices.

BackgroundDentin hypersensitivity is a short, severe pain with fast onset. Therapy aims to either prevent or decrease neural transmission or physically occlude the dentinal tubules. This study aimed to evaluate the effectiveness of commercial desensitizing dentifrice by means of an ex vivo method.Material and MethodsSamples (n=8 lower human premolars for each group) were randomly allocated into: G1- brushing with Colgate®Sensitive Pro-Relief; G2- brushing with Sensodyne®Rapid Relief; G3- brushing with Sensodyne®Repair & Protect; and G4- brushing with Colgate®Maximum Cavity Protection. The test bodies were submitted to simulated toothbrushing and dentifrices were analyzed regarding their hydrodynamic size, polydispersity index (PI) and zeta potential. Specimens were evaluated using: scanning electron microscopy (SEM); spectroscopy energy dispersive X-ray (EDS); and profilometry. A qualitative analysis of the photomicrographs and topographies was performed.ResultsThe dentifrices showed statistical similar physical and chemical characteristics. They also demonstrated obliteration of dentinal tubules when micrographs were observed. Regarding the chemical elements present in the dentin samples, there was a statistically significant difference between the control and experimental surfaces in the four groups.ConclusionsJoint data analysis shows that the desensitizing dentifrice showed better results with regards to the obliteration of dentinal tubules compared to positive and negative controls. Key words:Dentin hypersensitivity, dentin desensitizing agents, toothpastes.

Ability of three desensitizing agents in dentinal tubule obliteration and durability: An in vitro study.

Aim:The purpose of this study was to evaluate the effectiveness of three desensitizing agents on dentinal tubule obliteration and their durability in use on the dentinal tubules.Materials and Methods:Sixty specimens were obtained from 30 extracted sound human maxillary first premolars. Each tooth was mesiodistally sectioned to obtain 30 buccal and 30 lingual surfaces, and enamel was removed in order to simulate hypersensitive dentin. Specimens were divided into four groups with 15 specimens each. Group 1 samples were immersed in artificial saliva, Group 2 samples were coated with Vivasens, Group 3 samples were coated with VOCO Admira Protect, and Group 4 samples were coated with Neo Active Apatite suspension. These specimens were examined under scanning electron microscope (SEM) to find out the occluding ability of the respective products. The specimens were brushed to find out their durability for 1 week and 1 month and were examined under SEM.Statistical Analysis:The results were statistically analyzed by analysis of variance (ANOVA) and Tukey's test.Results:Group 1 differed significantly from the Vivasens, Admira, and Neo Active Apatite groups at 5% level of significance (P < 0.05). The Vivasens group differed significantly from the Admira and Neo Active Apatite groups at 5% level of significance (P < 0.05).Conclusion:The Ormocer-based Admira Protect showed the best results.

Comparative evaluation of desensitizing agent Vivasens and Laser for obliteration of dentinal tubules

Introduction: The purpose of this study was to evaluate the ability of desensitizing agents VivaSens and Laser (Diode) on dentinal tubule occlusion and its effectiveness over time using scanning electron microscopy (SEM). Materials and Methods: Twenty-two extracted human maxillary premolars were selected and grouped as follows: Group I: VivaSens (Ivoclar), Group II: Diode laser, and Group III: Control group. Teeth were embedded in plaster of Paris molds, and cavities of 2 mm depth and 3 mm width were prepared on a buccal surface at the cervical region. Ten specimens were coated with VivaSens (Ivoclar) and ten specimens were lased with Diode laser (i lase-Biolase) whereas two specimens remained as control. These specimens were examined under SEM to find the occluding ability of agents and also their efficacy with time. The statistical analysis was done using ANOVA, post hoc test, and Student's t-test. Results: Both VivaSens and Diode laser were equally effective in the obliteration of dentinal tubules just after application as well as after 15 days of treatment. No statistically significant difference was found between VivaSens and Laser groups. Conclusions: From the limitations of this study, it can be concluded that occlusion and narrowing of open dentinal tubules have been successfully achieved with both treatment approaches throughout the specific period.

Clinical and Ultrastructural Effects of Different Liners/Restorative Materials on Deep Carious Dentin: A Randomized Clinical Trial

We evaluated the effect of calcium hydroxide cement (CHC) and glass ionomer cement (GIC) on carious dentin and bacterial infections after partial caries removal and sealing. Sixty permanent teeth with deep lesions underwent partial caries removal, the application of CHC, GIC or wax, i.e. negative control (NC), and were then sealed for 3–4 months. After the partial caries removal and the sealing period, the dentin was clinically assessed (colour and consistency) and analysed by scanning electron microscopy to assess dentin organization and bacterial infections. The effect of the treatment in each group was assessed by the Wilcoxon and χ² tests, differences among groups by the Kruskal-Wallis test and the correlations between variables by Spearman correlation. No clinical symptoms or radiographic signals of pulpits or pulp necrosis were observed during the study. Dentin darkening was observed after the sealing period in the CHC and NC groups (p < 0.05). However, there was no difference in the colour after treatment among the 3 groups (p > 0.05). Dentin hardening occurred in all groups after treatment (p < 0.05), also with no differences (p > 0.05). Dentin samples showed better organization after the sealing period than after partial caries removal, with total or partial obliteration of dentinal tubules (CHC p < 0.03, GIC p < 0.05, NC p < 0.01) and a reduction of bacterial infections (CHC p < 0.03, GIC p < 0.05, NC p < 0.03). No differences were observed. Correlations between the different criteria, except for colour and bacterial infection, were detected in all cases. Partial caries removal and sealing resulted in dentin hardening, decreased bacterial numbers and dentin reorganization, irrespective of the dentin protection used.

Effect of Erbium-Doped Yttrium Aluminium Garnet Laser Parameters on Ablation Capacity and Morphology of Primary Dentin

To evaluate the ablation capacity of different energies and pulse repetition rates of an erbium-doped yttrium aluminium garnet (Er:YAG) laser on primary dentin by assessing mass loss and to analyze the surface morphology using scanning electron microscopy (SEM). Previous studies have demonstrated the ability of the Er:YAG laser to ablate dentin substrate. Forty-eight sound primary molars were bisected in the mesiodistal direction. The dentin surfaces were flattened, and initial mass (mg) was obtained. A 4-mm2 area was delimited. Specimens were randomly assigned to 12 groups according to the combination of energy (160, 200, 250, and 300 mJ) and pulse repetition rate (2, 3, and 4 Hz). Er:YAG laser irradiation was performed for 20 s. After irradiation, the final mass was obtained, and specimens were prepared for SEM. The data obtained by subtracting the final mass from the initial mass were statistically analyzed using analysis of variance and Tukey test (alpha=0.05). The pulse repetition rate of 4 Hz provided greater mass loss, and it was different from 2 Hz and 3 HZ. The energy of 300 mJ resulted in greater mass loss, similar to 200 and 160 mJ. SEM micrographs showed dentinal tubule obliteration, structural alterations, and the presence of cracked areas in all specimens. The settings of 160, 200, and 250 mJ at 2 and 3 Hz promoted a good ablation rate with fewer surface alterations in primary dentin.