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Introduction: Dental erosion and abrasion pose significant clinical challenges, often leading to exposed dentinal tubules and dentine demineralization. The aim of this study was to analyse the efficacy of quercetin-encapsulated hollow mesoporous silica nanocomposites (Q@HMSNs) on the prevention of dentine erosion and abrasion.Method: Q@HMSNs were synthesized, characterized, and evaluated for their biocompatibility. A total of 130 dentine specimens (2 mm × 2 mm × 2 mm) were prepared and randomly distributed into 5 treatment groups (n = 26): DW (deionized water, negative control), NaF (12.3 mg/mL sodium fluoride, positive control), Q (300 μg/mL quercetin), HMSN (5.0 mg/mL HMSNs), and Q@HMSN (5.0 mg/mL Q@HMSNs). All groups were submitted to in vitro erosive (4 cycles/d) and abrasive (2 cycles/d) challenges for 7 days. The specimens in the DW, NaF, and Q groups were immersed in the respective solutions for 2 min, while treatment was performed for 30 s in the HMSN and Q@HMSN groups. Subsequently, the specimens were subjected to additional daily erosion/abrasion cycles for another 7 days. The effects of the materials on dentinal tubule occlusion and demineralized organic matrix (DOM) preservation were examined by scanning electron microscopy (SEM). The penetration depth of rhodamine B fluorescein into the etched dentine was assessed using confocal laser scanning microscopy (CLSM). The erosive dentine loss (EDL) and release of type I collagen telopeptide (ICTP) were measured. The data were analysed by one-way analysis of variance (ANOVA) with post hoc Tukey’s test (α = 0.05).Results: Q@HMSNs were successfully synthesized and showed minimal toxicity to human dental pulp stem cells (HDPSCs) and gingival fibroblasts (HGFs). Q@HMSNs effectively occluded the dentinal tubules, resulting in a thicker DOM in the Q@HMSN group. The CLSM images showed more superficial penetration in the HMSN and Q@HMSN groups than in the quercetin, NaF, and DW groups. The Q@HMSN group exhibited a significantly lower EDL and reduced ICTP levels compared to the other groups (p < 0.05).Conclusion: Q@HMSNs hold promise for inhibiting dentine erosion and abrasion by promoting tubule occlusion and DOM preservation.

As a global public health focus, oral health plays a vital role in facilitating overall health. Defected teeth characterized by exposure of dentin generally increase the risk of aggravating oral diseases. The exposed dentinal tubules provide channels for irritants and bacterial invasion, leading to dentin hypersensitivity and even pulp inflammation. Cariogenic bacterial adhesion and biofilm formation on dentin are responsible for tooth demineralization and caries. It remains a clinical challenge to achieve the integration of tubule occlusion, collagen mineralization, and antibiofilm functions for managing exposed dentin. To address this issue, an epigallocatechin-3-gallate (EGCG) and poly(allylamine)-stabilized amorphous calcium phosphate (PAH-ACP) co-delivery hollow mesoporous silica (HMS) nanosystem (E/PA@HMS) was herein developed. The application of E/PA@HMS effectively occluded the dentinal tubules with acid- and abrasion-resistant stability and inhibited the biofilm formation of Streptococcus mutans. Intrafibrillar mineralization of collagen fibrils and remineralization of demineralized dentin were induced by E/PA@HMS. The odontogenic differentiation and mineralization of dental pulp cells with high biocompatibility were also promoted. Animal experiments showed that E/PA@HMS durably sealed the tubules and inhibited biofilm growth up to 14 days. Thus, the development of the E/PA@HMS nanosystem provides promising benefits for protecting exposed dentin through the coordinated manipulation of dentin caries and hypersensitivity.

Aim: This in vitro study compared the effect of two commercially available silver diamine fluoride (SDF) products on dentinal tubule (DT) occlusion and dentin permeability., Methods: Sixty-six dentin discs (1.0 mm thick) were divided equally into six groups: acid-etched with no treatment (negative control-NC), etched and sealed with nail varnish (positive control-PC), non-etched and treated with Advantage Arrest (AA), non-etched and treated with Topamine (TP), etched and treated with AA, and etched and treated with TP. Eight specimens from each group were tested for permeability using the dye percolation method. The remaining three samples from each group were assessed for dentinal tubule occlusion, depth of SDF penetration, and elemental analysis using a scanning electron microscope coupled with an energy-dispersive X-ray (SEM/EDX) system. One-way ANOVA and Tukey's post hoc test were used to analyze the results., Results: TP exhibited lower (p < 0.05) dye percolation compared to AA. While both SDF materials showed a statistically similar (p > 0.05) penetration depth in the DT, none of them had the ability to completely occlude all the DTs. AA exhibited more silver and fluoride ion deposition on etched dentin than TP, and both materials showed a similar increase in the deposition of Ca and P compared to NC., Conclusions: Whereas the effectiveness of dentin tubule (DT) occlusion varies based on the material used, both tested SDF products exhibit the capability to seal dentinal tubules, decrease dentin permeability, and promote dentin remineralization. These findings suggest their potential advantage in managing dentin hypersensitivity., (© 2024 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

The tubule occlusion of two newly developed herbal toothpastes was examined. They were prepared based on the mixture of pomegranate peel and Equisetum arvense extracts with strontium acetate. The antimicrobial activity of pomegranate peel and E. arvense were determined using minimum inhibitory concentration (MIC). Then, 30 mid‐coronal dentin discs from the human third molars were etched for 30 s with the lemon juice (pH = 2.4). The specimens divided into the three groups. While the control group had 6 specimens, Groups 1 and 2 were including 12 specimens. Group 1 brushed with toothpaste containing 10% strontium acetate and 5% hydroalcoholic extracts of pomegranate peel, and Group 2 brushed with 5% strontium acetate, 5% hydroalcoholic extracts of E. arvense, and 5% hydroalcoholic extracts of pomegranate peel. Brushing was simulated for 6 months with 2 N loading. Then, 50% of discs in each group were immersed in lemon juice for 1 min. Moreover, specimens in control group were brushed with distilled water. Finally, all 30 discs were analyzed using scanning electron microscopy (SEM) and energy‐dispersive X‐ray spectroscopy (EDXS). The occluded dentin tubules were counted and statistically evaluated. It was found that the number of open dentin tubules decreases significantly after brushing with both tested toothpastes compared with control group (p <.001). Moreover, a significant difference was observed between two toothpastes before and after acid immersion process (p <.001). The SEM micrographs confirmed the dentin tubule occlusion of both herbal dentifrices. Besides, EDXS analysis approved the strontium and silica presence on the dentin tubules for the toothpaste which was based on E. arvense. [ABSTRACT FROM AUTHOR]

Background: Abalone (Haliotis varia Linnaeus) shells possess a high arginine content and are expected to be an alternative desensitisation material that is both insoluble and able to properly close dentinal tubules. Different methods of manufacturing abalone gel affect the molecular weight, hydrophilic or hydrophobic properties and protein content of the lysis. Purpose: This study aimed to determine the effects of different manufacturing methods on the dentinal tubule closure of abalone desensitisation gel. Methods: This study involved the extraction of abalone shells followed by preparative and thin-layer chromatography. The drying of the samples was carried out by the precipitation, drying, and addition methods. The research was divided into eight treatment groups, each consisting of three samples (F1, F2, F3). Each sample was applied to two study subjects’ post-extracted third molars, which were cut into disc shapes and subsequently etched with 6% citric acid. The percentage of dentinal tubule occlusion was calculated by Image J (NIH, USA) software. Data were analysed using three-way ANOVA. Results: The results showed that there were significant differences (p < 0.05) both in terms of the effects of the samples with deposition and addition on the occlusion of the dentinal tubules and in terms of the interactions between the samples with drying and addition. There was no significant difference (p > 0.05) in terms of the interactions of the samples’ three manufacturing methods. Conclusion: The manufacture of abalone gel as a desensitisation material requires a minimum of two interactions between the sample-making method and the addition, deposition, and drying methods. The best method was deposition.

Dentine hypersensitivity (DH) is one of the most common dental conditions affecting most adults during their lifetime. Tubule occlusion is a widely accepted method for treating DH. Current in‐vitro techniques such as focused ion beam, scanning electron microscopy (SEM), or hydraulic conductance that are used to determine tubule occlusion do not provide the depth of occlusion, are time‐consuming, expensive and the volume of dentine tested is limited. The presented study aimed to assess the ability of serial block‐face SEM (SBF‐SEM) to section dentine, to quantify the number of occluded tubules including the depth of penetration by NovaMin and stannous fluoride (SnF2) and to compare mineral density between the control and treated dentine. Results demonstrated that NovaMin provided a better occlusion with 100% of the tubules blocked at the surface compared to 83% for SnF2. The grayscale value (230.42) was significantly higher (p ≤ 0.05) after treatment with NovaMin compared to SnF2 (222.06) and the control (196.37), indicating increased mineral density and dentine mineralization. SBF‐SEM has the potential to be used for large volume analysis of bone‐like materials at high resolution with minimal sample preparation over a short period. It can be significantly useful in the development and research of new biomaterials. [ABSTRACT FROM AUTHOR]

Aim: To evaluate the efficacy of in-office and home-based products in the prevention of dentinal hypersensitivity on dentin discs. Methodology: Ninety-six dentin disc samples of 1 mm were divided equally into six groups as follows: TeethmateTM, Smartprotect®, novamin®, Arginine calcium carbonate, potassium oxalate with rinse and saline (control). After acid etching, test agents were applied, and eight samples in each group were subjected to citric acid. SEM examination (3000x) and statistical analysis were carried out. Results: Before citric acid challenge, novamin® and teethmate had superiority when compared to others (p<0.001), but there was no a statistical difference between novamin® and teethmate. After citric acid challenge, teethmate and smartprotect showed resistance on occluded tubules. The decreasing in the level of occluded tubules in novamin® group was statistically significant (p<0.05). In-office products including teethmate and smartprotect were found more successful compared to home-based products. Smartprotect resisted against to citric acid (0.506). Conclusion: Novamin® showed a successful occlusion in all tubules before acid challenge whereas; it was the most unsuccessful group after acid challenge when compared to other agents. In-office agents were found to be more successful in reducing dentine permeability than homecare products. In-office agents showed more resistance to acid attacks. Further studies are needed to assess the efficacy of desensitizer agents. [ABSTRACT FROM AUTHOR]

The efficacy of Copal Varnish (CV), dentin bonding agent (DBA), Nd:YAG laser and Er:YAG laser, which occludes dentin tubules by different mechanisms, was investigated in order to prevent unwanted coloration caused by methylene blue (MB) and phthalocyanine used in photodynamic therapy (PDT). 165 upper incisors included in the study. Root canals were prepared up to 30/0.6 size for all teeth using Protaper Next rotary files. Then the teeth were randomly divided into 2 main groups (n = 60); MB and phthalocyanine. Each main group was randomly divided into 5 subgroups (n = 15); Positive control, DBA, CV, Er:YAG and Nd:YAG. Root canals were filled with photosensitizers (PS) and activated after the dentin tubule occlusion method was applied to all teeth. Then, the residual PSs were removed by irrigation. Color measurements of the samples were carried out 5 different time periods. Clinically detectable color change was observed in all groups except for the negative control (ΔE≥3.3). It was determined that the positive control using MB caused more unwanted coloration in the CV on the 30th and 90th days compared to the phthalocyanine used in the 90th day (p < 0.05). While none of the dentin tubule occlusion methods were superior to each other in preventing undesirable coloration caused by phthalocyanine, Er:YAG caused less unwanetd coloration than CV only on the 90th day in preventing unwanted coloration caused by MB (p < 0.05). All dentin tubule occlusion methods used in the present study were effective in preventing some degree of unwanted discoloration. However, it was found that no technique could completely prevent unwanted coloration. [ABSTRACT FROM AUTHOR]

Introduction: Dental erosion and abrasion pose significant clinical challenges, often leading to exposed dentinal tubules and dentine demineralization. The aim of this study was to analyse the efficacy of quercetin-encapsulated hollow mesoporous silica nanocomposites (Q@HMSNs) on the prevention of dentine erosion and abrasion. Method: Q@HMSNs were synthesized, characterized, and evaluated for their biocompatibility. A total of 130 dentine specimens (2 mm × 2 mm × 2 mm) were prepared and randomly distributed into 5 treatment groups (n = 26): DW (deionized water, negative control), NaF (12.3 mg/mL sodium fluoride, positive control), Q (300 μg/mL quercetin), HMSN (5.0 mg/mL HMSNs), and Q@HMSN (5.0 mg/mL Q@HMSNs). All groups were submitted to in vitro erosive (4 cycles/d) and abrasive (2 cycles/d) challenges for 7 days. The specimens in the DW, NaF, and Q groups were immersed in the respective solutions for 2 min, while treatment was performed for 30 s in the HMSN and Q@HMSN groups. Subsequently, the specimens were subjected to additional daily erosion/abrasion cycles for another 7 days. The effects of the materials on dentinal tubule occlusion and demineralized organic matrix (DOM) preservation were examined by scanning electron microscopy (SEM). The penetration depth of rhodamine B fluorescein into the etched dentine was assessed using confocal laser scanning microscopy (CLSM). The erosive dentine loss (EDL) and release of type I collagen telopeptide (ICTP) were measured. The data were analysed by one-way analysis of variance (ANOVA) with post hoc Tukey's test ( α = 0.05). Results: Q@HMSNs were successfully synthesized and showed minimal toxicity to human dental pulp stem cells (HDPSCs) and gingival fibroblasts (HGFs). Q@HMSNs effectively occluded the dentinal tubules, resulting in a thicker DOM in the Q@HMSN group. The CLSM images showed more superficial penetration in the HMSN and Q@HMSN groups than in the quercetin, NaF, and DW groups. The Q@HMSN group exhibited a significantly lower EDL and reduced ICTP levels compared to the other groups ( p < 0.05). Conclusion: Q@HMSNs hold promise for inhibiting dentine erosion and abrasion by promoting tubule occlusion and DOM preservation., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Chen, Cheng, Yang, Su and Yu.)

Highlights • In-office desensitizing treatments reduced dentin permeability after application. • Erosion-abrasion cycles can remove treatments that occluded dentinal tubules. • Not all treatments could maintain low dentin permeability after erosion-abrasion cycles. Abstract Objective To evaluate dentin permeability and tubule occlusion of in-office desensitizing treatments, and to analyze their resistance to erosive/abrasive challenges. Design Ninety-one 1mm-thick dentin discs were immersed in EDTA solution for 5 min. After analyzing the maximum dentin permeability, the specimens were randomly allocated into 7 experimental groups (n = 10): Control (no treatment); Er,Cr:YSGG laser; Nd:YAG laser; Gluma Desensitizer; Duraphat; Pro-Argin toothpaste; Calcium Sodium Phosphosilicate (CSP) paste. The post-treatment permeability was assessed and then the specimens were subjected to a 5-day erosion-abrasion cycling protocol: 4x/day of immersion in citric acid solution (5 min;0.3%), followed by exposure to clarified human saliva (60 min). After the first and last acid challenges, specimens were brushed for 15 s, with exposure to the toothpaste slurry for total time of 2 min. Dentin permeability was re-measured (post-cycling). Percentage of dentin permeability for each experimental time was calculated in relation to the maximum permeability (%Lp). Data were analyzed with 2-way repeated measures ANOVA and Tukey tests (α = 0.05). Surface modifications were analyzed by scanning electron microscopy. Results In both experimental time CSP paste and Gluma Desensitizer did not differ from each other (p = 0.0874), and were the only groups that presented significantly lower %Lp than the Control (p = 0.026 and p = 0.022, respectively). After treatment, they were able to reduce dentin permeability in 82% and 72%, respectively. The %Lp post-cycling was higher than post-treatment value for all groups (p = 0.008). Dentin permeability increased 21% for CSP paste and 12% for Gluma, but they remained significant different from Control. Deposits on the surface were observed for CSP paste; and for Gluma, tubule diameters were shown to be smaller. Conclusions CSP paste and Gluma Desensitizer were the only treatments able to decrease dentin permeability post-treatment and to sustain low permeability post-cycling. [ABSTRACT FROM AUTHOR]

Objectives: The objective of this study is to determine whether a silicone impression material could precisely replicate dentine tubule changes following 4 weeks toothbrushing with occluding or non-occluding toothpaste and whether changes reflected hypersensitivity clinical assessment. Materials and methods: This was a single site, examiner blind, parallel, two treatment arm, randomised clinical trial. Participants were healthy, ≥18, with ≥1 sensitive tooth with exposed dentine, Schiff sensitivity score ≥2, and patent tubules with dentine occlusion score 4-5 as determined by scanning electron microscopy of replica impressions. Nine participants received Sensodyne® Rapid Relief (occluding toothpaste) and 10 Crest® Decay Prevention (non-occluding toothpaste), and were re-evaluated for sensitivity and occlusion score after two timed minutes and 4 weeks twice-daily home brushing. Results: Occlusion scores did not correlate significantly with pain scores, but correlations were positive and impressions showed characteristic dentine tubule patency and occlusion. After 4 weeks, thermal VAS was significantly lower than baseline for the non-occluding toothpaste; all other pain scores were significantly lower for both treatments. Dentine occlusion scores also decreased after 4 weeks of either treatment, but did not achieve significance ( p = 0.0625). Conclusions: Both toothpastes reduced clinical sensitivity and increased tubule occlusion. It is hypothesised that during impression, taking some material may have sheared off and occluded tubules resulting in false positives. Clinical relevance: This study has demonstrated that a silicone impression material can accurately replicate the dentine surface to demonstrate dentine tubular occlusion and patency; however, although the association between occlusion and pain score was positive, this technique needs to be refined before use in future studies. [ABSTRACT FROM AUTHOR]

Introduction: Dentinal hypersensitivity is an exaggerated response to non-noxious sensory stimuli (osmotic, thermal or mechanical changes). An inverse relationship between occluding open tubules and the intensity of sensitivity has been reported. Studies on the efficacy of potassium nitrate used in different forms and frequencies to occlude dentinal tubules are scarce. Aim: To evaluate, in vitro the dentinal tubule occluding effect of potassium nitrate which differ in form, frequency and duration of application. Materials and Methods: In an in vitro study, 45 extracted human maxillary and mandibular premolars were sectioned using diamond disc to obtain 90 samples which were treated with 6% citric acid and were randomly assigned to three groups: Group 1 was treated with potassium nitrate toothpaste (once and twice daily for two minutes); Group 2 with potassium nitrate mouthwash (once and twice daily for two minutes) and Group 3 served as control (distilled water). Post-treatment, the samples were immersed in distilled water. The samples were subjected to Scanning Electron Microscopy (SEM) at the end of 3, 7 and 14 days. SEM photographs were analysed based on extent of tubular occlusion. Chi-square test was applied to assess the significant difference between the groups. Results: There was detectable difference in the dentinal tubule occlusion at the end of 3rd, 7th and 14th day between three groups. When compared to the mouthwash, toothpaste yielded better results. Twice daily application for a period of two minutes each was better when compared to once daily for two minutes. Conclusion: Potassium nitrate is effective in occluding dentinal tubules when applied twice daily in toothpaste form than mouthwash form. However, randomised control trials are needed to confirm its efficacy in human subjects.

Introduction: Dentin hypersensitivity (DH) is a sudden short sharp pain best explained by hydrodynamic theory. Several agents are available throughout the market that can treat DH either by blocking the nerves that helps in conducting pain or by blocking the open dentinal tubules. The aim of the present study was to compare the tubule occluding efficacy of four different desensitizing dentifrices under scanning electron microscope (SEM). Materials and Methods: Sixty-two dentin blocks measuring 5 mm x 5 mm x 3 mm were obtained from extracted human molar teeth and were randomly divided into five groups: Group 1-no treatment (control, n = 2); Group 2-Pepsodent Pro-sensitive relief and repair (n = 15); Group 3-Sensodyne repair and protect (n = 15); Group 4 -Remin Pro (n = 15); Group 5 - Test toothpaste containing 15% nano-hydroxyapatite (n-HA) crystals (n = 15). The specimens were brushed for 2 min/day for 14 days and stored in artificial saliva. After final brushing, specimens were gold sputtered and viewed under SEM at x2000 magnification. Results obtained were statistically analyzed using nonparametric Kruskal-Wallis test and least significant difference post hoc test. Results: All test groups showed significant increase in dentin tubule occlusion as compared to control group. The highest percentage of tubules occluded was shown by Group 4 and Group 5 which was significantly different from other groups (P ⩽0.05) and there was no significant difference in tubule occlusion among them. Conclusion: Newer desensitizing dentifrices containing 15% n-HA and Remin Pro can provide effective tubule occlusion and thereby reduce the pain and discomfort caused by DH. [ABSTRACT FROM AUTHOR]

The present investigation evaluated the ability of an experimental di-calcium phosphate (DCP) desensitising agent used alone or combined with phytosphingosine (PHS) to occlude dentine tubules and resist a citric acid (CA) or artificial saliva (AS) challenge. Three groups of human dentine specimens (DS) were treated with the following: (1) PHS alone, (2) DCP or (3) a combination of PHS and DCP. Dentine hydraulic conductance of DS was evaluated using a digital flow sensor at 6.9 kPa. The average fluid volume for each of the treated DS was used to calculate the total dentine permeability reduction (%P) prior to and following CA immersion for 1 min or AS immersion for 4 weeks. The treated DS were subjected to both scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy analysis. Statistically significant differences (%P) were identified between the groups by ANOVA and Fisher's multiple comparison test (p < 0.05), respectively. Interestingly, both PHS and DCP appeared to work synergistically. DS treated with DCP or PHS/DCP demonstrated a significant reduction (%P) prior to and following CA or AS challenge (p < 0.05). Both the SEM and FTIR analyses showed consistent brushite crystals occluding the dentine tubules. Conversely, the application of PHS alone failed to demonstrate any significant reduction of dentine permeability (p > 0.05) or show any evidence of occlusion of the dentine tubules. DCP can be used alone or combined with PHS to decrease the dentine permeability as well as to resist a CA and AS challenge. These results would, therefore, suggest that DCP may be a suitable treatment option for dentine hypersensitivity. [ABSTRACT FROM AUTHOR]

Aim: This in vitro study evaluated the degree of dentinal tubule occlusion and depth of penetration of nano-hydroxyapatite (nHAp) derived from chicken eggshell powder with and without the addition of 2% sodium fluoride (NaF) using scanning electron microscope (SEM) and confocal laser scanning microscope (CLSM). Materials and Methods: nHAp was synthesized and characterized using X-ray diffraction and SEM-energy dispersive spectroscopy. Dentin discs were obtained from extracted teeth, pretreated with 17% ethylenediaminetetraacetic acid for 5 min and were divided into four groups based on the experimental agents as follows: Group 1: Untreated (control), Group 2: 2% NaF, Group 3: nHAp, Group 4: Combination of nHAp and 2% NaF. The treatment protocol was carried out for 7 days, after which the specimens were viewed under SEM and CLSM. Statistical Analysis Used: One-way ANOVA and Tukey's post hoc multiple comparison tests (P < 0.05). Results: All the experimental agents occluded the dentinal tubules, but to varying degrees and depths. Specimens treated with the combination of nHAp and 2% NaF showed complete dentinal tubular occlusion and significantly greater depth of penetration than those treated with nHAp and 2% NaF alone. Conclusion: The combination of nHAp and 2% NaF was the most effective in occluding dentinal tubules. [ABSTRACT FROM AUTHOR]

Objectives: Dentin hypersensitivity (DH) is treated by either occlusion of dentin tubules or nerve desensitization. This in situ study compared dentin tubules occlusion by theobromine-containing dentifrices with (Theodent-classic-F®, TCF) and without (Theodent-classic®, TC) fluoride with 1,500 ppm fluoride toothpaste, Colgate®-Regular (Fluoride) and Novamin®-containing toothpaste, Sensodyne®-5000-Nupro (Novamin®). Methods: Each subject wore four intraoral appliances bearing dentin blocks while using one of four test dentifrices ( n = 20/dentifrice) twice daily for 7 days. The four appliances were removed successively after 1, 2, 3, and 7 days. Treated blocks and their control (untreated) blocks were examined with scanning electron microscopy (SEM). Effects were compared statistically (ANOVA/Tukey's) based on percentage of surface area covered by deposited precipitate layer (%DPL) and percentage of fully open (%FOT), partially occluded (%POT), and completely occluded (%COT) tubules in each block calculated relative to the number of tubules in their control blocks. Results: SEM observation indicated an increased %COT and %DPL over time. After 1 and 2 days, %COT was comparable with TC and TCF, and significantly ( p < 0.05) higher compared with Novamin® and Fluoride. Following 3 and 7 days, %COT was comparable among TC, TCF, and Novamin®, but remained significantly lower in Fluoride. At any time, %DPL was significantly ( p < 0.05) higher in TC, TCF, and Novamin® compared with Fluoride. Conclusions: Theobromine-containing toothpastes with and without fluoride have equal potential in occluding dentin tubules within a shorter time period than Novamin®-containing toothpaste; however, the three demonstrated equal potential after 1 week, but not the fluoride toothpaste. Clinical relevance: Theobromine-containing toothpaste promoted dentin tubule occlusion thus shows potential to relief DH. [ABSTRACT FROM AUTHOR]

Introduction: Dentinal hypersensitivity is an exaggerated response to non-noxious sensory stimuli (osmotic, thermal or mechanical changes). An inverse relationship between occluding open tubules and the intensity of sensitivity has been reported. Studies on the efficacy of potassium nitrate used in different forms and frequencies to occlude dentinal tubules are scarce. Aim: To evaluate, in vitro the dentinal tubule occluding effect of potassium nitrate which differ in form, frequency and duration of application. Materials and Methods: In an in vitro study, 45 extracted human maxillary and mandibular premolars were sectioned using diamond disc to obtain 90 samples which were treated with 6% citric acid and were randomly assigned to three groups: Group 1 was treated with potassium nitrate toothpaste (once and twice daily for two minutes); Group 2 with potassium nitrate mouthwash (once and twice daily for two minutes) and Group 3 served as control (distilled water). Post-treatment, the samples were immersed in distilled water. The samples were subjected to Scanning Electron Microscopy (SEM) at the end of 3, 7 and 14 days. SEM photographs were analysed based on extent of tubular occlusion. Chi-square test was applied to assess the significant difference between the groups. Results: There was detectable difference in the dentinal tubule occlusion at the end of 3rd, 7th and 14th day between three groups. When compared to the mouthwash, toothpaste yielded better results. Twice daily application for a period of two minutes each was better when compared to once daily for two minutes. Conclusion: Potassium nitrate is effective in occluding dentinal tubules when applied twice daily in toothpaste form than mouthwash form. However, randomised control trials are needed to confirm its efficacy in human subjects. [ABSTRACT FROM AUTHOR]

As a global public health focus, oral health plays a vital role in facilitating overall health. Defected teeth characterized by exposure of dentin generally increase the risk of aggravating oral diseases. The exposed dentinal tubules provide channels for irritants and bacterial invasion, leading to dentin hypersensitivity and even pulp inflammation. Cariogenic bacterial adhesion and biofilm formation on dentin are responsible for tooth demineralization and caries. It remains a clinical challenge to achieve the integration of tubule occlusion, collagen mineralization, and antibiofilm functions for managing exposed dentin. To address this issue, an epigallocatechin-3-gallate (EGCG) and poly(allylamine)-stabilized amorphous calcium phosphate (PAH-ACP) co-delivery hollow mesoporous silica (HMS) nanosystem (E/PA@HMS) was herein developed. The application of E/PA@HMS effectively occluded the dentinal tubules with acid- and abrasion-resistant stability and inhibited the biofilm formation of Streptococcus mutans . Intrafibrillar mineralization of collagen fibrils and remineralization of demineralized dentin were induced by E/PA@HMS. The odontogenic differentiation and mineralization of dental pulp cells with high biocompatibility were also promoted. Animal experiments showed that E/PA@HMS durably sealed the tubules and inhibited biofilm growth up to 14 days. Thus, the development of the E/PA@HMS nanosystem provides promising benefits for protecting exposed dentin through the coordinated manipulation of dentin caries and hypersensitivity., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2022 The Authors.)

Objective: To compare the efficacy of a new potassium oxalate (KO)-containing mouthrinse [Listerine® Advanced Defence Sensitive (LADS)] in reducing dentine permeability and occluding open dentinal tubules versus other desensitising products. Methods: The permeability of acid-etched dentine disks was measured by hydraulic conductance; dentine surfaces were examined by scanning electron microscopy and energy-dispersive X-ray spectroscopy. The KO concentration was optimised for tubule occlusion by screening formulations containing 0.0-2.0% KO (n=5 disks per concentration). The optimal formulation was compared with five commercial products with non-oxalate occlusion technologies. After establishing the baseline permeability of acid-etched dentine disks, disks (n=6 per product) were randomly treated with the desensitising products (12 treatments, each 60 s, alternated with distilled-water rinses) and permeability was measured at intervals. Occluded disks were acid challenged. All experiments were conducted at room temperature. An unpooled, two-tailed t test was performed to assess between-treatment differences in relative residual permeability. Results: The optimal concentration of KO in LADS was 1.4%, which provided ~100% reduction in dentine permeability after nine treatments. Only LADS reduced permeability to zero and was significantly more effective in reducing dentine permeability than the other products (p≤0.033 vs all other test products). All products partially occluded dentine. The occlusion associated with LADS was substantially more stable in resisting acid challenge versus Colgate® Sensitive Pro-Relief mouthrinse (p=0.054) and significantly more stable versus all other test products (p≤0.045), as determined by dentine permeability. Conclusions: LADS was significantly more effective in occluding open dentinal tubules versus other desensitising products. Clinical significance: LADS provides fast, complete and stable intratubular occlusion of patent dentinal tubules. [ABSTRACT FROM AUTHOR]

Objectives: This review defines dentine sensitivity (DS), its prevalence, its aetiology, the mechanism(s) responsible for DS, its diagnosis and its treatment. The review then examines the modes of action of various treatments for DS including potassium salts, strontium salts, bioglasses, arginine/calcium carbonate and professional treatments such as adhesives and oxalates. The methods used to evaluate the various treatment modalities are discussed, including laboratory studies and randomised controlled clinical trials. Data sources and study selection: A literature search was conducted using PubMed, Ovid Medline and Cochrane reviews for information on DS and its treatments, as well as laboratory and clinical studies used to evaluate the efficacy of various DS treatments. With regard to efficacy of treatments for DS only reports of clinical studies that were randomised, controlled and blinded were reviewed. The authors offer new insights into the shortcomings of the recent systematic review of the use of oxalates for DS. Conclusions: The authors introduce the concept of a novel desensitising mouthrinse containing 1.4% potassium oxalate: Listerine® Advanced Defence Sensitive mouthrinse. Readers of this supplement issue of the Journal of Dentistry are invited to review the significance of managing the clinical problem of DS. They are also invited to assess data from laboratory and randomised controlled clinical studies in order to understand the advantages offered by regular use of 1.4% potassium oxalate-containing mouthrinse, Listerine Advanced Defence Sensitive, in particular its resistance to daily erosive and/or abrasive challenges. [ABSTRACT FROM AUTHOR]

Objective: To investigate the ability of a novel mouthwash comprised of 0.8% arginine, PVM/ MA copolymer, pyrophosphates, and 0.05% sodium fluoride in an alcohol-free base (Pro- ArginTM Mouthwash Technology) to reduce dentine permeability. Methods: Hydraulic conductance was used to assess the dentine permeability effects of the arginine mouthwash. Aqueous solutions containing arginine and PVM/MA copolymer were studied in the initial stage of the method development. The acid resistance was tested with a cola drink challenge. Finally, a blinded study was carried out to determine the occlusion of the arginine mouthwash in comparison to a negative control mouthwash. Results: Dentine discs treated with the arginine mouthwash showed an average fluid reduction of 42%, which was statistically, significantly better than the fluid reduction for the negative control mouthwash. In addition, experiments using simple solutions of arginine and PVM/MA copolymer, alone and in combination, demonstrated that the combination of the two was required to provide a relevant occlusion benefit. Finally, the occlusion provided by the arginine mouthwash was maintained after exposure to an acid challenge. Conclusion: The exclusive combination of ingredients in the arginine mouthwash has been proven to be efficacious in decreasing dentine fluid flow as measured by hydraulic conductance. The new mouthwash works by occlusion, due to the unique combination of arginine, PVM/MA copolymer and pyrophosphates. [ABSTRACT FROM AUTHOR]

Objective: Tooth sensitivity is a common, painful dental condition. Consumer dental products, mostly dentifrices, play an important role in sensitivity treatment. The objective of this review is to describe a new mouthwash-based desensitizing technology. Data: Background literature concerning desensitizing products is reviewed. Potassium salts are the most commonly used active ingredients in desensitizing dentifrices. Clinical studies show that while potassium salt dentifrices are generally effective; most formulations require several weeks to exert their desensitizing effect. Recently, a new desensitizing dentifrice containing the amino acid arginine was introduced. This dentifrice acts to occlude the dentinal tubules, and has been shown to be highly effective in multiple clinical studies. This arginine-containing dentifrice has also been shown to provide instant relief of sensitivity pain when applied directly to the sensitive tooth surface. In contrast to dentifrices, there are few desensitizing mouthwashes available. Building on the success of the arginine-based dentifrice, an arginine-based mouthwash formula was developed and tested. Sources: Published studies in peer-reviewed publications. Study selection: Controlled and blinded clinical studies to provide evidence of efficacy. In vitro studies are included to indicate the mechanism of action. This review includes studies testing the new arginine-based desensitizing mouthwash. Conclusion: Clinical findings indicate that this new desensitizing mouthwash, based on the Pro-ArginTM mouthwash technology effectively reduces sensitivity symptoms and can be used alone or as a adjunct to the use of the arginine-containing dentifrice in the home treatment of tooth sensitivity. [ABSTRACT FROM AUTHOR]

Abstract: Objective: To evaluate in vitro the effectiveness of different calcium-silicate (CS) cements specifically designed for dentine permeability reduction. Design: Fifty dentine discs were prepared from caries free human molars extracted for surgical reasons. The treatment consisted in applying two different experimental CS cements on dentine surface. Dentine discs treated only with EDTA served as negative control group. Treatment with D-Sense Crystal and Clearfil S3-Bond served as positive control groups. After treatment samples were immersed in artificial saliva. The quantitative changes in the hydraulic conductance (i.e. permeability) through dentinal tubules were quantified using a hydrostatic device working at 6.9kPa. Dentine permeability was measured immediately after EDTA treatment, 10min and 1 week after treatment application and immersion of dentine samples in artificial saliva. SEM/EDX analyses were performed to obtain qualitative information on dentine morphology and surface deposits. Results: The experimental CS cements reduced dentine permeability immediately after application and also 10min and 1 week after the immersion of the specimens in artificial saliva. D-Sense Crystal and Clearfil S3-Bond showed higher levels of dentine permeability after 1 week of immersion in artificial saliva. Conclusions: CS cements reduced dentine permeability in vitro even after immersion in artificial saliva, which makes them new valuable candidates for treatment of dentine hypersensitivity in vivo. [Copyright &y& Elsevier]

Abstract: Objectives: To investigate the dentine occlusion and acid resistance of dentifrices developed to treat dentine hypersensitivity. Methods: This was a single centre, single blind, randomised, split mouth, four treatments, two period crossover, in situ study in healthy subjects. Subjects wore buccal intra-oral appliances each fitted with four dentine samples over four consecutive days with one study product applied per appliance; 8% strontium acetate in silica base, 1040ppm sodium fluoride (Sensodyne® Rapid Relief), 8% arginine, calcium carbonate, 1450ppm sodium monofluorophosphate (Colgate Sensitive Pro-Relief®), 1450ppm sodium fluoride (control paste) and water. On days 3 and 4, two agitated grapefruit juice challenges (ex vivo) occurred for 1min. At the end of each treatment day 1 dentine sample was removed from each appliance for scanning electron microscopy (SEM). The extent of tubule occlusion was measured using an examiner-based visual scoring index (three trained examiners). Results: In total, 28 subjects ((12 males and 16 females with a mean age of 34.7 years (SD 8.41 years)) completed the study. On day 2, both test dentifrices demonstrated significantly better dentine tubule occlusion than water (p <0.0001) and control paste (8% strontium p =0.0003 and 8% arginine p =0.0019). After 3 and 4 days of twice daily brushing with acid challenges on days 3 and 4 the strontium-based dentifrice demonstrated significantly better dentine occlusion than all other treatments (p <0.0001). Conclusions: Strontium acetate and arginine-based dentifrice result in statistically significant dentine tubular occlusion compared to controls, but the arginine-based dentifrice is more susceptible to acid challenge. Clinical significance: Erosive beverages are an important aetiology in DH by exposing dentine tubules. Their consumption has increased significantly over the past decade in the UK. This 4-day in situ study investigated the properties of commercially available dentifrices designed to occlude dentine tubules and their resistance to an agitated acid challenge. [Copyright &y& Elsevier]

Although hydrophobic resins may be bonded to acid-etched dentin with an ethanol wet-bonding technique, the protocol is sensitive to moisture contamination when bonding is performed in deep dentin. This study tested the hypothesis that the use of oxalate or poly(glutamic) acid-modified, diluted ceramicrete (PADC) for dentinal tubule occlusion prevents fluid contamination and improves the bonding of an experimental hydrophobic adhesive to acid-etched, ethanoldehydrated dentin. Mid-coronal and deep acidetched moist dentin pre-treated with oxalate or PADC was dehydrated by ethanol wet-bonding and infiltrated with the experimental three-step etch-and-rinse hydrophobic adhesive under simulated pulpal pressure. Tensile bond strengths to deep dentin without pre-treatment were severely compromised. Conversely, oxalate and PADC pretreatments reduced dentin permeability, prevented water contamination, and improved bond strengths. Minimal nanoleakage was identified within hybrid layers created in the oxalate- and PADC-pre-treated deep dentin. The use of tubular occluding agents optimized bonding of hydrophobic resins to dentin. [ABSTRACT FROM AUTHOR]

In-office products containing oxalates have been claimed to be clinically effective in reducing dentine sensitivity, although there has been limited supporting clinical data. The rationale for their use appears to be based on their potential to act as occluding and/or nerve desensitizing agents. Four commercially available oxalate-containing products were applied to etched dentine discs and the extent of tubule occlusion was observed by scanning electron microscopy. Tenure Quick (aluminium oxalate), Sensodyne Sealant (ferric oxalate) and MS Coat (oxalic acid) covered the dentine surface and occluded the tubules. However, Butler Protect (potassium oxalate) did not cover the surface to any great extent but provided some occlusion. The presence of oxalates after application to glass slides and dentine discs was examined using thin film X-ray diffraction. From samples on glass, only potassium oxalate could be clearly identified (JCPDS 14-0845). No oxalate was detected on dentine discs in either thin film geometry or standard theta two theta mode. We have demonstrated that professionally applied in-office products containing oxalate are capable of covering the dentine surface and/or occluding the tubules to varying degrees. However, X-ray diffraction analysis was unable to confirm the oxalate profile for all products as described in the available commercial literature. [ABSTRACT FROM AUTHOR]

Dentin sensitivity (DS) is a painful clinical condition which may affect 8-35% of the population. Various treatment modalities have claimed success in relieving DS, although at present there does not appear to be a universally accepted desensitizing agent. Current opinion based on Brännström's Hydrodynamic Theory would suggest that following exposure of the dentin surface (through attrition, abrasion, or erosion), the presence of open dentinal tubules, patent to the pulp, may be a prerequisite for DS. The concept of tubule occlusion as a method of dentin desensitization, therefore, is a logical conclusion from the hydrodynamic theory. The fact that many of the agents used clinically to desensitize dentin are also effective in reducing dentin permeability tends to support the hydrodynamic theory. This paper reviews the in vitro evaluation of desensitizing agents, the techniques used to characterize their effects on the prepared dentin surface, and the ability of these agents to reduce permeability through tubule occlusion, and presents recent findings from ongoing research based on the Pashley Dentin Disc model. It can be concluded that the use of this model to determine surface characteristics, and reductions in dentin permeability through tubule narrowing or occlusion, provides a useful screening method for evaluating potential desensitizing agents. Interpreting changes observed in vitro is difficult, and extrapolation to the clinical situation must be tempered with caution. [ABSTRACT FROM AUTHOR]