Combination of strontium chloride and photobiomodulation in the control of tooth sensitivity post-bleaching: A split-mouth randomized clinical trial.

OBJECTIVE: This split-mouth randomized controlled clinical trial assessed the effect of 10% strontium chloride in combination with photobiomodulation (PBM) for the control of tooth sensitivity (TS) post-bleaching. METHODS: The upper/lower, right and left quadrants of fifty volunteers were randomized and allocated to four groups (n = 25): PLACEBO-placebo gel + simulation of PBM; Placebo + PBM; STRONTIUM-10% strontium chloride + simulation of PBM; and PBM + STRONTIUM-10% strontium chloride + PBM. All groups received tooth bleaching treatment with 35% hydrogen peroxide. For the PBM treatment, the laser tip was positioned in the apical and cervical regions of the teeth bleached in the respective hemi-arch. The laser system was operated in continuous mode, using 1.7 J of energy. A dose of 60 J/cm2 was applied to each point for 16 seconds under 808 nm near-infrared light (100mW of power), with a point area of 0.028 cm2. TS was assessed during a 21-day follow-up, using the modified visual analogue scale. RESULTS: In the intragroup assessment, the Friedman test indicated that PBM + STRONTIUM promoted the greatest reduction in TS after the second week of treatment (p ≤ 0.05). The Wilcoxon-Mann-Whitney test indicated that the groups Placebo + PBM, STRONTIUM, and STRONTIUM + PBM did not differ statistically (p ≥ 0.05) in the first and third weeks of treatment The group PLACEBO exhibited the greatest TS in the first three days after each bleaching session. CONCLUSION: The combination of 10% strontium chloride with PBM was effective in reducing post-bleaching TS; however, the combination of 10% strontium chloride with PBM was effective in reducing post-bleaching TS; however, it did not differ from the individual use of Placebo + PBM or STRONTIUM groups assessed after 21 days of follow-up.

A randomized clinical trial of dentin hypersensitivity reduction over one month after a single topical application of comparable materials.

Dentinal hypersensitivity (DH) is a condition that causes patient discomfort. To evaluate the clinical efficacy of Gluma, fluoride varnish and Tetric N-Bond self-etch system in relieving DH immediately and over 30 days following a single topical application. The present randomized clinical trial was conducted on 55 patients with an age range 20-49 years. 70 teeth in total were incorporated and randomly assigned to the three groups. Parameters examined were: Tactile, air blast, and cold stimuli. VAS was used to assess tactile stimulus whereas the Schiff Cold Scale for air blast and cold stimuli. DH was evaluated immediately, at two weeks and 1 month follow up. Gluma showed a statistically significant reduction in DH scores over other materials. It was concluded that Gluma have statistically significant results over other materials in relieving DH immediately and over 30 days following a single topical application.Trial Registration: Clinical Trials.gov Identifier: NCT04351412, King Abdulaziz University Protocol Record 129-09-19. Registered 17 April 2020 - Retrospectively registered. http://ClinicalTrials.gov/NCT04351412 .

Effects of microsurface structure of bioactive nanoparticles on dentinal tubules as a dentin desensitizer.

In this in vitro study, spherical mesoporous bioactive glass nanoparticle (MBGN) and non-porous bioactive glass nanoparticle (BGN) were fabricated. The impact of mesopores on dentinal tubule occlusion and bioactivity was compared to examine the potential of these materials in alleviating dentine hypersensitivity (DH). MBGN, dense BGN were synthesized by sol-gel methods and characterized. Bioactivity and ion dissolution ability were analyzed. Twenty-four simulated sensitive dentin discs were prepared and randomly divided into three groups (n = 8 each); Group 1, no treatment; Group 2, Dense BGN; Group 3, MBGN. Then, four discs per group were treated with 6wt.% citric acid challenge to determine the acidic resistance. The effects on dentinal tubule occlusion were observed by FESEM. The microtensile bond strength (MTBS) was also measured. Cytotoxicity was examined using the MTT assay. According to the results, dense BGN without mesopore and MBGN with mesopore were successfully fabricated. Dense BGN and MBGN occluded the dentinal tubule before and after acid challenge. However, only MBGN formed a membrane-like layer and showed hydroxyapatite formation after soaking SBF solution. There were no significant differences in MTBS among dense BGN, MBGN (P>0.05). The cell viability was above 72% of both materials. The higher bioactivity of MBGN compared with that of dense BGN arises from the structural difference and it is anticipated to facilitate dentin remineralization by inducing hydroxyapatite deposition within the dentinal tubule.

Effects of oligopeptide simulating DMP-1/mineral trioxide aggregate/agarose hydrogel biomimetic mineralisation model for the treatment of dentine hypersensitivity.

Dentine hypersensitivity (DH) occurs when dentine is exposed to stimuli from the oral environment due to a lack of enamel or cementum. The use of biomimetic mineralisation in occluding exposed dentinal tubules and regenerating enamel-like tissues on dentine surfaces is preferred for a long-lasting treatment. In this study, we established a biomimetic mineralisation model composed of oligopeptide stimulating dentine matrix protein 1 (DMP-1), mineral trioxide aggregate (MTA) and an agarose hydrogel biomimetic mineralisation model (AHBMM); the proposed model is thus referred to as DMP-1@MTA@AHBMM. The effectiveness of DMP-1@MTA@AHBMM for the management of DH was analysed with scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction, Fourier transform infrared spectroscopy and a microhardness test. The use of DMP-1@MTA@AHBMM on a demineralised dentine surface occluded the dentinal tubules and regenerated an enamel-like tissue containing well-defined fluoridated hydroxyapatite crystals on the dentine surface. The microhardness of the regenerated enamel-like tissue was greater than that of the demineralised dentine. Therefore, DMP-1@MTA@AHBMM can be a promising method for the management of DH.

Root surface demineralization by citric acid/tetracycline gel and aPDT associated to subepithelial connective tissue graft improves root coverage outcomes. A 12-month preliminary randomized clinical trial.

Root conditioners are used to promote root surface biomodification to increase the success rate of root coverage. Citric acid and tetracycline are commonly used. There is recent indication for using antimicrobial photodynamic therapy (aPDT) with this purpose. The aim of this study is to evaluate the effects of citric acid/tetracycline gel and aPDT in root coverage of gingival recessions using subepithelial connective tissue graft. This parallel, double-blinded clinical trial enrolled 17 patients (60 recession defects; 20/group). Experimental groups were: Control group (SRP) - scaling and root planing only; Citric acid/tetracycline gel (CAT) group - SRP plus citric acid/tetracycline gel; aPDT - SRP, toluidine blue O (100 µl/ml) and red laser. At baseline and after 3, 6 and 12 months, the clinical parameters were evaluated: recession depth (RD), percentage of root coverage (%RC), keratinized tissue width (KTW), soft tissue thickness (STT), probing depth (PD), clinical attachment level (CAL), dentin hypersensitivity (HYPER) and esthetic perception by patient (EST). CAT group presented reduction in PD, CAL, RD, increase in KTW and STT, higher %RC (81.6%) and better esthetic in relation to SRP group (p < .05). aPDT treatment promoted CAL reduction, gain of KTW and STT and higher %RC (82.1%) in relation to SRP (57.7%) (p < .05). There was a reduction in dentin sensitivity in all groups. Complete root coverage was higher for CAT group (65%) and aPDT group (70%) in relation to SRP (30%) (p < .05). Root conditioning, with citric acid/tetracycline gel and aPDT, promotes better long-term clinical outcomes and root coverage after SCTG procedures.

Non-carious cervical lesions and risk factors: A case-control study.

OBJECTIVES: To evaluate whether the presence of non-carious cervical lesions (NCCLs) was related to the considered risk factors and to show the corresponding odds ratio in a predictive model. METHODS: The sample was 280 dentistry students. In an initial clinical examination, 140 cases were selected that presented one or more teeth with non-carious cervical wear. For each case, a similar sex and age control without any tooth with non-carious cervical lesions was selected. An occlusal examination and periodontal probing were performed in all cases and controls by skilled dentists. All the subjects answered a questionnaire referring to factors of brushing, bruxism, preferred chewing side, consumption of extrinsic acids and the presence of intrinsic acids. Data were analysed by means of univariate and multivariate logistic regression. RESULTS: Of all the study variables, only the protrusion interferences, interferences on the non-working side, the brushing force, CPITN value and the consumption of salads increase the risk of NCCLs in the univariate regression. The best predictive model was formed by the combination of CPITN variables >1, the consumption of acidic salads, self-reported bruxism, brushing force and attrition. However, it only correctly classifies 68.75% of subjects. CONCLUSIONS: This study supports the multifactorial aetiology of NCCLs, the combination of several factors being necessary to explain their presence. The risk factors that make up the predictive model are not sufficient to explain the appearance of NCCLs. Dentists should take into account all these risk factors in prevention, diagnosis and treatment.

Improved reactive nanoparticles to treat dentin hypersensitivity.

The aim of this study was to evaluate the effectiveness of different nanoparticles-based solutions for dentin permeability reduction and to determine the viscoelastic performance of cervical dentin after their application. Four experimental nanoparticle solutions based on zinc, calcium or doxycycline-loaded polymeric nanoparticles (NPs) were applied on citric acid etched dentin, to facilitate the occlusion and the reduction of the fluid flow at the dentinal tubules. After 24 h and 7 d of storage, cervical dentin was evaluated for fluid filtration. Field emission scanning electron microscopy, energy dispersive analysis, AFM and Nano-DMA analysis were also performed. Complex, storage, loss modulus and tan delta (δ) were assessed. Doxycycline-loaded NPs impaired tubule occlusion and fluid flow reduction trough dentin. Tubules were 100% occluded in dentin treated with calcium-loaded NPs or zinc-loaded NPs, analyzed at 7 d. Dentin treated with both zinc-NPs and calcium-NPs attained the highest reduction of dentinal fluid flow. Moreover, when treating dentin with zinc-NPs, complex modulus values attained at intertubular and peritubular dentin were higher than those obtained after applying calcium-NPs. Zinc-NPs are then supposed to fasten active dentin remodeling, with increased maturity and high mechanical properties. Zinc-based nanoparticles are then proposed for effective dentin remineralization and tubular occlusion. Further research to finally prove for clinical benefits in patients with dentin hypersensitivity using Zn-doped nanoparticles is encouraged. STATEMENT OF SIGNIFICANCE: Erosion from acids provokes dentin hypersensitivity (DH) which presents with intense pain of short duration. Open dentinal tubules and demineralization favor DH. Nanogels based on Ca-nanoparticles and Zn-nanoparticles produced an efficient reduction of fluid flow. Dentinal tubules were filled by precipitation of induced calcium-phosphate deposits. When treating dentin with Zn-nanoparticles, complex modulus values attained at intertubular and peritubular dentin were higher than those obtained after applying Ca-nanoparticles. Zn-nanoparticles are then supposed to fasten active dentin remodeling, with increased maturity and high mechanical properties. Zinc-based nanogels are, therefore, proposed for effective dentin remineralization and tubular occlusion. Further research to finally prove for clinical benefits in patients with dentin hypersensitivity using Zn-doped nanogels is encouraged.

Clinical features and factors associated with non-carious cervical lesions and dentin hypersensitivity.

Determining the factors associated with NCCLs and DH in populations could guide the implementation of specific preventive measures. This study evaluated the clinical features and factors associated with non-carious cervical lesions (NCCLs) and dentin hypersensitivity (DH) in a Brazilian population. The participants were 118 patients at the Dentistry Clinic of our dental school. They completed an interview to obtain personal information and determine the possible factors associated with NCCLs and DH. Clinical examination was undertaken to record the NCCLs, shape of the lesion and certain occlusal factors. DH was diagnosed by air and probe tests. Data were analysed with the multilevel Poisson regression and prevalence ratios, and the respective 95% confidence intervals were calculated. The prevalence of NCCLs and DH among patients was 67·8% and 51·7%, respectively. Of a total number of 2902 teeth examined, 9·65% had NCCLs and 5·82% were sensitive to air. The most affected teeth for both conditions were the premolars. Most of the NCCLs were wedge-shaped and located in the maxilla. The factors associated with NCCLs and DH were age and presence of premature occlusal contacts. NCCLs were also significantly associated with consumption of wine and alcoholic beverages, and DH with consumption of acidic fruits and juices. NCCLs were a common finding, with higher frequency in more advanced age groups, the maxilla and premolars. A significant association occurred between NCCLs, premature contacts and consumption of wine and alcoholic beverages. DH was associated with NCCLs, premature contacts and with the consumption of acidic fruits and juices.

Age-related morphological, histological and functional changes in teeth.

Throughout lifetime, the teeth are continuously exposed to numerous chemical and physical impacts, which cause the wear of the dental hard tissues, gingival recession and other oral changes with sometimes subsequent problems. Age-related wear of tooth surfaces reduces the dental enamel thickness and exposes deeper layers of enamel, which have different physical and chemical properties than the surface enamel. Gingival recession is the main causal factor of root caries and dentine hypersensitivity. Age-related changes in dentine include the formation of secondary dentine and the reduction in tubular lumen diameter (dentine sclerosis), which lead to a reduction in the volume of the pulp chamber. In addition to the reduction in the volume of pulp chamber, changes to the dental pulp also include dental pulp calcifications. The age-related physiological changes to the teeth should be carefully distinguished from pathological changes, especially when they induce pain or a negative impact on the oral health-related quality of life (OHRQoL) of the older individuals. Therefore, regular oral examinations coupled with early preventive measures should aim at maintaining oral health until old age.

Stress and its role in the dentin hypersensitivity in rats.

INTRODUCTION: The perception of pain varies individually. Chronic stress leads to analgesia. The use of animal chronic mild stress model to mimic human condition was previously developed and now applied in the evaluation of pain perception in rats with dentin hypersensitivity (DH). AIMS: Using DH model induced by dentin erosion (DE) mediated by acidic solution, the present study aimed the evaluation of the interaction of chronic stress and pain induced by DH in rats with DE. METHODS: DH was induced by ad libitum 30-day intake of acidic solution. Stress was induced by the New York subway model. Body weight was weekly taken, during treatment. Groups WO (water, no stress), WS (water and stress), EO (acidic solution, no stress) and ES (acidic solution, stress) were submitted to treatments. RESULTS: After 30 days, all groups were submitted to DH test assessed by cold water stimuli in the labial surface of molars, for 5s, and the rats responses were scored as grades 0, 0.5, 1, 2, or 3. After euthanasia, blood was taken to obtain the levels of corticosterone, stomachs were observed in fresh preparations, kidneys and livers were submitted to histological evaluation. Open field model supported stress evaluation, as did corticosterone analysis. Stressed animals showed significant increase in pain perception and a decrease in locomotion frequency, tending to be more frequent in the periphery of the arena, corroborating stressed behavior and the need of protection as a pain relief. Corticosterone levels were increased in the stressed rats with dentin erosion and also corroborate present findings. Finally, reduction in weight gain was impaired in stressed group with dentin erosion. CONCLUSION: The animal model enabled the evaluation of how chronic mild stress interfered in DH pain perception.

Non-carious cervical lesions (NCCLs) in a random sampling community population and the association of NCCLs with occlusive wear.

This study investigated the prevalence, risk factors and association of occlusive wear with non-carious cervical lesions (NCCLs) in the general Chinese population. A total of 1320 subjects were recruited, and multistage and random sampling methods of survey spots were performed. All age groups comprised similar numbers of participants and equal numbers of males and females. Each subject completed a structured interview, and all teeth of each subject were examined by a practitioner to determine NCCLs and occlusive wear. Binary logistic regression was conducted by analysing the association of risk factors with the occurrence of NCCLs. Bivariate correlation analysis was performed by determining the association of NCCLs dimension or depth with the range of occlusive wear facets. Clinical assessment showed that the overall prevalence of subjects diagnosed with NCCLs was 63%. The proportion of subjects or teeth with NCCLs significantly increased with age. Pre-molars were the most commonly affected teeth. Single variables and interactive effects of variables associated with the occurrence of NCCLs include the following: age group, intensity of toothbrushing, frequency of fresh fruit consumption and interactive effect between intensity of toothbrushing and frequency of fresh fruit consumption. A weak positive correlation of the grading index was found between NCCLs dimension, size or depth and range of occlusive wear facets. This study reported the higher prevalence of NCCLs in the general Chinese population. Implementation of a combined strategy to reduce risk factors of NCCLs could be more effective than individual techniques; meanwhile, the occurrence of NCCL could be related to the wear degree of occlusive defects in the population studied.

Dentin tubule occluding ability of dentin desensitizers.

PURPOSE: To compare the dentin tubule-occluding ability of fluoroaluminocalciumsilicate-based (Nanoseal), calcium phosphate-based (Teethmate Desensitizer), resin-containing oxalate (MS Coat ONE) and diamine silver fluoride (Saforide) dentin desensitizers using artificially demineralized bovine dentin. METHODS: Simulated hypersensitive dentin was created using cervical dentin sections derived from bovine incisors using phosphoric acid etching followed by polishing with a paste containing hydroxyapatite. The test desensitizers were applied in one, two, or three cycles, where each cycle involved desensitizer application, brushing, and immersion in artificial saliva (n= 5 each). The dentin surfaces were examined with scanning electron microscopy, and the dentin tubule occlusion rate was calculated. The elemental composition of the deposits was analyzed with electron probe microanalysis. Data were analyzed by one-way ANOVA and the Tukey honestly significant different test. RESULTS: Marked deposit formation was observed on the specimens treated with Nanoseal or Teethmate Desensitizer, and tags were detected in the specimens' dentin tubules. These findings became more prominent as the number of application cycles increased. The major elemental components of the tags were Ca, F, and Al (Nanoseal) and Ca and P (Teethmate Desensitizer). The tubule occlusion rates of MS Coat ONE and Saforide were significantly lower than those of Nanoseal and Teethmate Desensitizer (P< 0.05).

Absence of Non-Carious Cervical Lesions (NCCLs) in a Chilean Pre-Columbian Sample with Severe Occlusal Tooth Wear / Ausencia de Lesiones Cervicales no Cariosas (NCCLs) en una Muestra Chilena Precolombina con Severo Desgaste Oclusal

This study evaluates the non-carious cervical lesions (NCCLs) and the occlusal tooth wear in a pre-Columbian sample (n= 67, adults) from San Pedro de Atacama (North of Chile, 400-1300 BCE). The cervical regions of tooth were observed for loss of enamel and/or dentine in order to identify them as NCCLs and the tooth wear was characterized by the Basic Erosive Wear Examination (BEWE) index. None of the individuals analyzed presented NCCLs, whereas the 98.5% (66/67) of them showed occlusal wear. The mean BEWE index was 2.5, indicating severe dental wear (3 being the highest possible score of BEWE). This lack of relation among severe tooth wear and NCCLs gives support to the idea of loss of crown height reduces cervical stress and develop of NCCLs in archaeological populations.

Este estudio evalúa las lesiones cervicales no cariosas (NCCLs) y el desgaste dental oclusal en una muestra precolombina (n= 67, adultos) de San Pedro de Atacama (Norte de Chile, 400-1300 AEC). Se analizó la perdida de esmalte y/o dentina en las áreas cervicales de los dientes con el propósito de identificarlas como NCCLs y el desgaste dental fue evaluado según el índice Basic Erosive Wear Examination (BEWE). Ninguno de los individuos analizados presentó NCCLs, mientras el 98,5% (66/67) de ellos mostró desgaste oclusal. El promedio del índice BEWE fue de 2,5, indicando severo desgaste dental (siendo 3 el puntaje más alto posible). La falta de relación entre severo desgaste dental y NCCLs apoya la idea que la pérdida de altura de las coronas reduce el estrés cervical y el desarrollo de NCCLs en poblaciones arqueológicas.

Treatment of dentinal hypersensitivity by means of Nd:YAP Laser: a preliminary in vitro study.

OBJECTIVE: The aim of this study is to evaluate the effectiveness of Nd:YAP laser to seal dentinal tubules at different parameters. MATERIAL AND METHODS: 24 caries-free human wisdom impacted molars were used. The crowns were sectioned transversally in order to totally expose the dentin. The smear layer was removed by a 1 min application of EDTA. Each surface was divided into four quadrants, but only three quadrants were irradiated at a different output power setting (irradiation speed: 1 mm/sec; optical fiber diameter: 320 µm; tangential incidence of beam and in noncontact mode). Samples were smeared with a graphite paste prior to laser irradiation. All specimens were sent for SEM analysis. Pulp temperature increases in additional twenty teeth were measured by a thermocouple. RESULTS: Morphological changes in dentin surfaces depend on the value of used energy density. Higher energy densities (2 W-4 W; 200-400 mJ; pulse duration: 100 m sec.; and 10 Hz) induce higher dentin modifications. Our results confirmed that Nd:YAP laser irradiations can lead to total or partial occlusion of dentin tubules without provoking fissures or cracks. Measurements of pulp temperature increases showed that Nd:YAP laser beam can be considered as harmless for pulp vitality for following irradiation conditions: 2 W (200 mJ) to 4 W (400 mJ) with an irradiation speed of 1 mm/sec; fiber diameter: 320 micrometers; 10 Hz; pulse duration: 100 m sec; noncontact mode and in tangential incidence to exposed dentin. The perpendicular incidence of the laser beam on exposed dentin may injure pulp vitality even at low output power of 3 W. CONCLUSIONS: Nd:YAP laser beam was able to seal the dentin tubules without damaging dentinal surfaces and without harming pulp vitality. Nd:YAP laser is effective and may be safely used for future in vivo treatments of dentinal hypersensitivity under certain conditions.

Dentine hypersensitivity.

Dentine hypersensitivity is a common oral pain condition affecting many individuals. The aetiology is multifactorial; however, over recent years the importance of erosion has become more evident. For dentine hypersensitivity to occur, the lesion must first be localised on the tooth surface and then initiated to exposed dentine tubules which are patent to the pulp. The short, sharp pain symptom is thought to be derived from the hydrodynamic pain theory and, although transient, is arresting, affecting quality of life. This episodic pain condition is likely to become a more frequent dental complaint in the future due to the increase in longevity of the dentition and the rise in tooth wear, particularly amongst young adults. Many efficacious treatment regimens are now available, in particular a number of over-the-counter home use products. The basic principles of treatment are altering fluid flow in the dentinal tubules with tubule occlusion or modifying or chemically blocking the pulpal nerve.

Combined effects of Er:YAG laser and nano-carbonate apatite dentifrice on dentinal tubule occlusion: in vitro study.

OBJECTIVE: The aim of this study was to evaluate the occluding effects of Er:YAG laser and dentifrice containing nano-carbonate apatite (n-CAP) on the dentinal tubules. BACKGROUND DATA: Although there are various treatment methods for dentin hypersensitivity (DH), more effective methods are still being sought. METHODS: Sound human root dentin specimens were etched with 6% citric acid to open the dentinal tubules. The specimens were divided randomly into four groups: no treatment (control group), toothbrushing using 20% n-CAP dentifrice (n-CAP group), Er:YAG laser irradiation (LI group), and LI after n-CAP (combined group). The degree of occlusion of the dentinal tubules and the thickness of the deposition layer were evaluated by scanning electron microscopy and an image analyzer. RESULTS: It was shown that the occlusion effect of the n-CAP group was 87%, that of the combined group was 54%, and that of the LI group was 52%, compared with that of the control group. And the n-CAP particles were observed not only under the irradiated surface and but also above the surface in the combined group. CONCLUSIONS: This combination method has the potential for enhancement of the dentinal tubule occlusion. However, further study is needed to present the combination effects with additional analysis, and the long-term effects.

In vitro remineralization of enamel subsurface lesions and assessment of dentine tubule occlusion from NaF dentifrices with and without calcium.

UNLABELLED: Currently, fluoride is the most effective preventive treatment for remineralization of incipient carious lesions and dentinal hypersensitivity due to wasting disorders. The products containing fluoride, calcium and phosphate are also claim to remineralize early, non-cavitated enamel demineralization. The aim of this study was to investigate and compare the efficacy of two such products, Tooth Mousse and Clinpro tooth crème on remineralization and tubule occluding ability with 5000ppm fluoride-containing toothpaste. MATERIALS AND METHODS: Thirty third molar teeth were placed in demineralizing solution for 5 days such that only a window of 1mm x 5mm was exposed to the environment to produce artificial caries-like lesions and randomly assigned to three groups: Group I, 5000ppm sodium fluoride; Group II, GC MI paste plus and Group III, Clinpro tooth crème. Axial longitudinal sections of 140-160 µm of each tooth which included the artificial carious lesion taken and were photographed under polarized light microscope. The demineralized areas were then quantified with a computerized imaging system. The experimental materials were applied onto the tooth sections as a topical coating and subjected to pH-cycling for 28 days. To evaluate tubule occlusion ability, thirty dentin specimens of 2mm thickness were obtained from cervical third of sound third molars. Specimens were ultrasonicated and etched with 6% citric acid for 2 minutes to simulate the hypersensitive dentin. Specimens were randomly divided into above mentioned three groups (n=10). The test agents were brushed over the specimens with an electric toothbrush, prepared and observed under Scanning Electron Microscope for calculation of the percentage of occluded tubules. RESULTS: Group I showed a significantly greater percentage of remineralization than Group III and Group II. Comparison of the remineralization potential between group II and group III were not significant.In case of dentine hypersensitivity, Group I and group III showed greater percentage of tubule occlusion ability than Group II. Intergroup comparison of the tubule occlusion potential of group I and group III were not significant. INTERPRETATION AND CONCLUSION: Within the limitations of our study, sodium fluoride showed relatively greatest remineralizing and dentinal tubule occlusion property when compared with GC MI paste plus and Clinpro tooth crème.

Effect of Er,Cr:YSGG laser on human dentin fluid flow.

The aim of the current investigation was to assess the rate and magnitude of dentin fluid flow of dentinal surfaces irradiated with Er,Cr:YSGG laser. Twenty extracted third molars were sectioned, mounted, and irradiated with Er,Cr:YSGG laser at 3.5 and 4.5 W power settings. Specimens were connected to an automated fluid flow measurement apparatus (Flodec). The rate, magnitude, and direction of dentin fluid flow were recorded at baseline and after irradiation. Nonparametric Wilcoxon signed ranks repeated measure t test revealed a statistically significant reduction in fluid flow for all the power settings. The 4.5-W power output reduced the flow significantly more than the 3.5 W. The samples showed a baseline outward flow followed by inward flow due to irradiation then followed by decreased outward flow. It was concluded that Er,Cr:YSGG laser irradiation at 3.5 and 4.5 W significantly reduced dentinal fluid flow rate. The reduction was directly proportional to power output.

In vitro evaluation of dentinal hydraulic conductance and tubule sealing by a novel calcium-phosphate desensitizer.

In the current trend of materials used for dentin hypersensitivity treatment, calcium-phosphate-containing desensitizers are expected to have advantages in oral environment. A newly formulated desensitizer containing tetracalcium phosphate and dicalcium phosphate anhydrous (CPD-100) was evaluated in comparison to oxalate containing desensitizer (SS) regarding permeability reduction (PR%) by measuring hydraulic conductance on the etched dentin discs in vitro. CPD-100 exhibited mean PR% of 91%, which significantly increased to 98% after immersion in artificial saliva (AS) for 4 weeks (p < 0.001), while SS showed a significant decrease from 99% to 93% (p < 0.01). SEM observation showed newly formed crystallites on CPD-100 treated dentin, which did not exist in SS treated dentin after AS immersion, suggesting that calcium oxalate inhibited formation of new calcium-phosphate minerals. Five-minute acid challenge did not significantly affect PR% of dentin treated by any of the desensitizers. The energy dispersive X-ray spectroscopy (EDS) analysis indicated that the formed layer of CPD-100 were minerals with similar Ca/P ratio to hydroxyapatite. In conclusion, the newly developed calcium-phosphate desensitizer has the potential to exhibit long-term stability in the oral environment, owing to its chemical properties that promote the crystal growth in salivary fluid.

The efficacy of 8% Arginine-CaCO3 applications on dentine hypersensitivity following periodontal therapy: a clinical and scanning electron microscopic study.

OBJECTIVES: Periodontal therapy is one of the etiological factors of dentine hypersensitivity (DH). This study aimed to evaluate the efficacy of %8Arginine-CaCO3 on DH that affects patients after periodontal treatment. STUDY DESIGN: Seventy-one teeth from the volunteers (n=36) with history of DH caused by periodontal therapy were included in this study, and randomly divided into two groups: group-1, who received 8%Arginine-CaCO3 and group-2, who received 1.23%NaF-gel. The clinical indices were recorded at first visit.DH was evaluated by using tactile, air-blast, and thermal stimuli. The subject's response was recorded at baseline, immediately (Day-0) and one month after the application. RESULTS AND CONCLUSIONS: The results were statistically analyzed, and it was found that 8% Arginine-CaCO3 treatment was more effective than 1.23% NaF-gel at time intervals. Sensitivity score differences between the groups were statistically significant at Day-28. The 8% Arginine-CaCO3 group exhibited statistically significant reduction in DH on three stimuli at baseline to Day-28. It was concluded that 8% Arginine-CaCO3 is more effective than 1.23% NaF-gel in reduction of patients' pain.