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Dentin hypersensitivity (DH) is characterized by short or transient sharp pain arising from exposed dentin in response to thermal, physical, osmotic, or chemical elements (Holland et al., 1997, West et al., 2011). According to the hydrodynamic theory, hypersensitivity results from the rapid movement of the fluid within the dentinal tubules (Brannstrom et al., 1968). It is imperative to the efficacy of the DH treatment to address the etiological factors of the condition (Femiano et al., 2017). Desensitizing therapies consist of the use of chemical substances, laser irradiation, restorative treatments, periodontal surgeries which aim basically to control the hydrodynamic mechanisms of pain. However, these treatments do not achieve predictable results in all patients and may lose their effect over time (Cartwright, 2014, Zhu et al., 2015, Sole-Magdalena et al., 2017). Bioactive glass materials have been proposed for the treatment of DH (David, 2010, Curtis et al., 2010, Barry et al., 2011, Sauro et al., 2011, Cartwright, 2014, Hall et al., 2017, Bansal and Mahajan, 2017). The mechanism of action of bioactive glass starts when the material is exposed to an aqueous environment. The sodium ions (Na+) in the particles immediately are switched with hydrogen cations (H+ or H3O+). This rapid release of ions allows the calcium ions (Ca+2) in the particle structure, as well as the phosphate ions (PO4-3), to be released from the glass particles. The initial reactions occur in seconds of exposure and the release of the Ca+2 and PO4-3 ions continues as long as the particles are exposed to an aqueous environment. A localized and transient increase in pH occurs during the initial material exposure due to the release of Na+. This increase in pH helps to precipitate the Ca+2 and PO4-3 ions of the particle to form a layer of calcium phosphate Ca(PO4)2. As particle reactions and the deposition of calcium and phosphorus complexes are maintened, the layer crystallizes into hydroxycarbonate apatite which is chemically and structurally equal to biological apatite. The combination of residual particles and the newly formed apatite layer lead to physically occluding the dentin tubules, resulting in remission or pain reduction (Zhong et al., 2002, Zanotto et al., 2004, Hench, 2006). The maintenance of this layer on the dentin surface is a major challenge for the materials existing in the market, besides knowing the effectiveness of them for the treatment of DH. Studies have shown the absence of parameters such as: patient follow-up time, control groups, assessment scale for degree of pain, DH diagnostic methods and form of application of the product (Matranga et al., 2017, Hannigan and Lynch, 2013, Kim et al., 2011, Pandis et al., 2011, Fleming et al., 2013). The use of bioactive materials is a promising proposal for DH due to the the neoformation of a bioactive barrier on dentin surface (Bansal and Mahajan, 2017). They showed the ability to occlude the dentinal tubules and form a mechanically strong layer of hydroxyapatite on the dentin surface, which can resist degradation by repeated acid challenges (Du et al., 2008). Thus, the aim of this systematic review was to assess randomized controlled trials (RCT) carried out in the permanent teeth of adult patients in the DH treatment with bioactive dentrifices, either at-home or in-office.

Dentin hypersensitivity can be reduced by the use of a remineralization agent to hinder movement of fluids within the dentin tubules. Penetration of particles into the tubules and a continuous release of Ca2+ and phosphate ions can induce the mineralization of a material mimicking the mineral component of dentin, sealing the tubules. In this work, we have used complementary electron microscopy techniques to investigate the ultrastructure of dentin and crystallization and occlusion effects when using amorphous calcium magnesium phosphate (ACMP) microspheres on extracted human molars. Application of the particles in a gel intended for at-home use resulted in intra-tubular mineralization of a carbonate substituted hydroxyapatite (HA). Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) showed that crystallization was initiated on the peritubular dentin (PTD) with undirected crystal growth leading to the formation of a porous material. We additionally investigated the effects from using a fluoride toothpaste to potentially improve the remineralization and anti-cariogenic properties of the ACMP microspheres. Energy dispersive x-ray spectroscopy (EDX) using TEM in scanning mode (STEM) showed that fluoride incorporation resulted in an increase in aspect ratio of the crystals, crystal growth directed towards the center of the tubule lumen and densification of the mineralized material. Thus, ACMP microspheres are promising alternatives as occluding agents and the efficacy of the particles could be further improved with the complementary use of a fluoride toothpaste.

Objective Dentin remineralization is of considerable clinical interest for dentin hypersensitivity and developing biomimetic analogs that can regulate hydroxyapatite (HAp) nucleation and growth remains a challenge. This study aimed to evaluate in vitro the potential for dentin remineralization using the following biomimetic in situ prepared poly(catechols): poly(dopamine), poly(DOPA), poly(caffeic acid) and a synthesized DOPA-peptide possessing collagen and calcium-binding domains (DOPA-Ahx-(Gly)3-(Glu)5). Methods Dentin samples were immersed in a freshly prepared phosphate-buffered saline (PBS) containing the respective catechol and laccase. After the reaction, they were immersed in calcium and phosphate remineralization solution, which was changed every day for 10 days. Samples of intact and demineralized dentin were used as control groups and kept in deionized water under the same experimental conditions. The remineralized dentin was characterized by scanning electron microscopy (SEM), Micro-energy dispersion X-ray fluorescence spectroscopy (μEDX) and X-ray diffraction (XRD). Results The application of different poly(catechols) and DOPA-peptide promoted crystal nucleation and the formation of HAp, which partially covered both the dentin surface and dentinal tubules walls. Significance By mimicking the role of charged non-collagenous proteins in vivo, polymers consisting of catechol groups showed the ability to modify demineralized dentin surface properties, promoting mineral formation. The use of poly(catechols) may be encouraged for the development of a therapeutic technique for dentin hypersensitivity.

Background This article highlights a stabilized stannous fluoride (SnF2) dentifrice that, in addition to being efficacious against caries, gingivitis, and dentin hypersensitivity, demonstrates high-performing stain prevention and removal efficacy. Methods An in vitro stain prevention model evaluated the efficacy of Colgate TotalSF containing 0.454% SnF2 and 1% zinc phosphate compared with Crest Pro-Health Whitening Power (The Procter & Gamble Company) and a nonabrasive SnF2 gel. L*, a*, and b* values were measured to assess whiteness comparing untreated and stained teeth, and with statistical analysis. A stain removal clinical study was conducted as a randomized, double-blind, 2-cell, parallel-group design using Colgate TotalSF and nonwhitening regular fluoride toothpaste. Participants were instructed to brush twice daily for 6 weeks and were examined for Lobene Composite Stain Index scores, with statistical analysis used at a significance of P Results In an in vitro stain prevention study, Colgate TotalSF performed 26% and 35% better than a competitor paste and nonabrasive SnF2 gel, respectively. In a clinical study, Colgate TotalSF use showed statistically significant extrinsic tooth stain reductions by 17.5% (3 weeks) and 27.8% (6 weeks) relative to regular fluoride toothpaste. No adverse effects were reported. Conclusions The results indicate that the stabilized Colgate TotalSF performed statistically better than other SnF2 pastes in an in vitro study, and statistically better than a regular fluoride toothpaste in a clinical study. Practical Implications Colgate TotalSF offers an SnF2-based therapeutic dentifrice with notable performance in stain prevention and removal.

To evaluate the desensitizing effect of nano-hydroxyapatite (n-HAP) on dentine hypersensitivity (DH).Seven electronic databases were searched on April 27, 2018.Randomized clinical trials (RCTs) were included based on the PICO strategy: Participants - Humans with DH; Intervention - n-HAP-containing desensitizing; Comparison -n-HAP-free treatments or placebo/negative control; and Outcomes - relief of DH. The risk of bias was classified by the Cochrane guidelines. Five meta-analyses were performed to evaluate the efficacy of n-HAP with regard to pain assessment stimuli (primary outcome); comparison of n-HAP with other treatments or placebo/negative control, and effectiveness of at-home and in-office n-HAP use (secondary outcomes). The quality of the evidence was evaluated using the GRADE.Six RCTs with 4 weeks of follow-up were included in the meta-analysis. For the primary outcome, n-HAP showed a better desensitizing effect for evaporative stimuli (SMD -1.09 [-1.24, -0.94], p 0.00001) and tactile stimuli (SMD -0.93 [-1.42, -0.43]) than other treatments (p = 0.0002). However, there was no difference between n-HAP and other treatments for the cold stimuli (SMD -0.17 [-0.81, 0.48], p = 0.61). In an overall analysis, n-HAP-containing treatment showing the most significant desensitizing effect (SMD -0.93 [-1.19, -0.68], p 0.00001) with a high quality of evidence for pooled results. In the secondary outcomes, n-HAP showed the best effect in the overall analysis (p 0.05) with moderate quality evidence.The n-HAP-containing treatment showed better clinical performance than other treatments for DH relief. However, long-term follow-up RCTs are required in the future before definitive recommendations can be made.Dentin hypersensitivity is a common global condition and its multifactorial etiology has led to the development of several treatments. The n-HAP-containing treatment showed greater DH relief when compared to other desensitizing agents, placebo or negative control.

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.

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.

Objective This study aimed to evaluate if in patients with dentin hypersensitivity (DH), the DH treatments are able to improve individuals’ oral health related quality of life (OHRQoL). Data and sources A systematic review was performed based on PRISMA guidelines (PROSPERO CRD42016050864). Clinical trials reporting OHRQoL before and after DH treatment were included. The search was performed in the PubMed/MEDLINE, Scopus, Web of Science, Cochrane Library, LILACS, EMBASE and Scielo databases until May 2017. Hand searches and grey literature were included. Three researches independently selected the studies, extracted data, and assessed the methodological quality. The risk of bias was estimated based on the Cochrane Handbook for Systematic Reviews of Interventions. Meta-analysis was performed by I2 test. The quality of evidence was assessed using Grading of Recommendations Assessment, Development and Evaluation (GRADE). Study selection Six clinical trials were included. DH was assessed by evaporative, cold, and tactile stimuli. OHRQoL was evaluated by OHIP-14 and DHEQ questionnaires. In-home and in-office desensitizing agents for DH treatment were used. The revised studies reported statistically significant reduction of DH and significant improvement in quality of life after treatment (p Conclusions The studies indicated decreasing of DH and improving of OHRQoL after DH treatment, although, they presented low to moderate methodological quality. Clinical significance The Oral Health Relate Quality of Life of whom complaint of DH can be improved after DH treatment.

Objective Eight repetitive nucleotide sequences of aspartate–serine–serine (8DSS) derived from dentin phosphoprotein (DPP) has been proved to be a good remineralization agency. In this study, 8DSS peptide was employed to induce dentinal tubule occlusion. Methods Dentin samples were acid-etched, and then the samples were coated with 8DSS solution. The binding capacity of 8DSS to acid-etched dentin was tested by attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR). Subsequently, the 8DSS-treated dentin samples were immersed in artificial saliva for 1, 2 and 4 weeks. After 4 weeks, the remineralized dentin was treated with 6 wt% citric acid (pH 1.5) solution for 1 min. Dentin permeability measurement and scanning electron microscopy (SEM) were carried out after different periods. Energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD) were used to identify the mineral phase of the regenerated minerals. Results The results showed that 8DSS had a good binding capacity to the acid-etched dentin, and significantly reduced the dentin permeability by inducing minerals deposited within the dentinal tubules. After 4 weeks, all the dentinal tubules were occluded by large bulk of regenerated minerals, which largely decreased the diameters of the tubules. The regenerated minerals deposited with a deep depth within the dentinal tubules, ensuring an effective occlusion even after an acid challenge. The results of XRD and EDS confirmed that the regenerated minerals were mainly hydroxyapatite (HA). Significance 8DSS peptide induced strong dentinal tubule occlusion. 8DSS have a great potential to be used in the treatment of dentin hypersensitivity in the future.

Objectives This study aims to apply electrophoretic deposition (EPD) for occlusion of dentinal tubules in vitro and investigate its effect on tubule occlusion and shear bond strength (SBS). Methods Charged mesoporous silica nanoparticles (MSNs) were synthesized and characterized through field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), dynamic light scattering (DLS), and Fourier transform infrared (FT-IR) spectroscopy analyses. Thirty-nine sensitive dentin specimens were modeled and assigned randomly to three groups with different treatments (n = 13 each): group 1, immersion in the MSN suspension; and groups 2 and 3, anodic EPD with the specimen on the negative and positive electrode respectively. The effect of dentinal tubule occlusion was evaluated by dentin permeability test (n = 10 each) and FESEM examination (n = 3 each). Moreover, 18 specimens were grouped (n = 6 each) and treated in the same method. A resin stick was bonded onto each of the specimen using a self-etch adhesive (single bond universal) for SBS testing. Results Negatively-charged MSNs were synthesized and characterized as small and well-dispersed particles. After the EPD treatment (group 3), the dentinal tubules were effectively occluded by MSNs, which infiltrated into the tubules at a depth of approximately 7–8 μm and tightly associated with the tubular inwalls. SBS was not significantly different among the three groups (P > 0.05). Conclusions Synthesized MSNs were deposited into dentinal tubules by EPD treatment without compromising dentin bond strength. Clinical significance Application of EPD is a new approach for occlusion of dentinal tubules and exhibits potential in the study of dentin hypersensitivity.

Introduction It has been suggested that alveolar corticotomies may accelerate tooth movement, broaden the scope of malocclusion types that can be treated orthodontically, decrease the need for extractions, and support long-term stability. Several techniques have been proposed, although the indications, ideal design and technical characteristics, potential complications, and objective clinician and patient satisfaction remain unclear. This systematic review aimed to provide scientific support to validate alveolar corticotomies as a reliable approach to accelerated orthodontics. Material & methods A literature search was conducted using MEDLINE (via PubMed), Cochrane, and EMBASE electronic databases until December, 2016. Articles written in any language other than English, Spanish, French, German, and Portuguese were excluded. Randomized controlled trials, controlled clinical trials, and case series involving healthy adult patients, with a sample size of at least 5 patients, and using alveolar corticotomy techniques were included. Two reviewers extracted the data independently. Results Three randomized clinical trials, 2 prospective randomized clinical trials, 6 case series and 1 randomized controlled split-mouth study were included. No clinical trials were retrieved. Mean total treatment time in corticotomy-facilitated orthodontic cases was 8.85 months (range, 4–20 months); control groups treatment duration was 16.4 months (range, 7.8–28.3 months). Complications such as pain, swelling, and dentin hypersensitivity were reported. Few studies mentioned patient/clinician satisfaction. The faster and less invasive procedures appeared to be well tolerated. However, the methodological quality of the selected studies was low, with only low to moderate scientific evidence. Conclusions Corticotomy-facilitated orthodontics resulted in decreased treatment time. Few complications and low morbidity were found. More solid evidence-based research is required to support these results.

Article Title and Bibliographic Information Efficacy of tunnel technique in the treatment of localized and multiple gingival recessions: A systematic review and meta-analysis. Tavelli L, Barootchi S, Nguyen TVN, Tattan M, Ravida A, Want H-L. J Periodontol 2018;89(9):1075-90. Source of Funding Nonprofit, foundations, university support: University of Michigan Periodontal Graduate Student Research Fund. Type of Study/Design Systematic review with meta-analysis of data.

The aim of this study was to investigate the binding ability of a arginine-glycine-aspartate-serine (RGDS) peptide to dentin and its effect on the dentin remineralization, dentin cohesive strength and intrafibrillar mineralization induced by nanobioactive glass (nBG). The demineralized dentin discs were treated with RGDS and/or nBG and then incubated in stimulated body fluid for 2 weeks. The results of scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction and confocal laser scanning microscopy showed that RGDS could bind to dentin and promote the attachment of nBG. Compared to the nBG group, the RGDS + nBG group induced more apatite formation on the dentin surface and apatite rods inside the dentinal tubules. The results of transmission electron microscopy showed crystal lattice formation in the demineralized dentin matrix treated with nBG or RGDS + nBG, indicating the remineralization of dentin. The RGDS + nBG-treated dentin had the highest dentin cohesive strength in all groups. The self-assembled collagen fibrils exposed to RGDS + nBG exhibited intrafibrillar mineralization. In conclusion, RGDS promoted nBG-induced apatite formation and dentin collagen matrix remineralization, thus enhancing the dentin strength. The results lay a foundation for the wide application of RGDS and nBG in dentin erosion, dentin hypersensitivity, dentin bonding interface improvement, and regenerative dentistry.

Background Dentin hypersensitivity is a relatively common pain symptom caused by evaporative, chemical, thermal, tactile, or osmotic stimuli. Despite its high prevalence, many aspects of dentin hypersensitivity remain unknown. Current treatments for dentin hypersensitivity include desensitizers and adhesive materials. Several factors that occur in the oral cavity, such as occlusal force and intrapulpal pressure, cause microleakage, the primary defect of adhesive treatments. Highlight (1) This review article explains the etiology and pain mechanisms of dentin hypersensitivity. (2) Microleakage, a primary cause of restoration failures, is emphasized. (3) Current and ideal treatments for dentin hypersensitivity are described. Conclusion The ideal treatment for dentin hypersensitivity should restore the original impermeability of the dentinal tubules. A novel way to treat dentin hypersensitivity is the regeneration of tubular dentin to overcome microleakage.

Bioactive glass (BG) is a potential material for treating dentin hypersensitivity owing to its high solubility. In this study, we synthesized 80S-BG bioactive glass samples using a sol–gel technique and mixed with various hardening agents. The obtained material could be used in human dentinal dentinal tubule occlusions. X-ray diffraction (XRD), scanning electronic microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR) measurements were employed to investigate the physiochemical properties and dentinal dentinal tubule occlusion efficiency by mixing the 80S bioactive glass (80S-BG) with various hardening agents. The major crystallite phase obtained on mixing 80S-BG with phosphoric acid (PA) was Ca(H 2 PO 4 ) 2 ·H 2 O. The mixture of 80S-BG powders and 20, 30, or 40 wt% PA acted as a hardening agent and achieved a dentinal tubule penetration depth of 30.7–62.6 µm. 80S-BG on mixing with suitable PA agents exhibited a short reaction time and good operability, making it feasible for use in occluding dentinal tubules. 80S-BG mixed with hardening agents exhibited a greater potential for treating dentin hypersensitivity as compared to the 80S-BG not mixed with any hardening agents.

Bioactive glass (BG) is a potential material for treating dentin hypersensitivity due to its high solubility. In this study, a commercial BG powder (PerioGlas®, PG) mixed with various hardening agents was applied in human dentinal tubule occlusions. X-ray diffraction (XRD), scanning electronic microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR) were used to investigate the re-crystallization behavior of human dentin and the dentinal tubule occlusion efficiency by mixing PG with various hardening agents. The major crystalline phases of PG mixed with phosphoric acid are CaHPO 4 ·2H 2 O and CaH 2 P 2 O 7 . PG mixed with 20 or 30 wt% phosphoric acid acted as a hardening agent and achieved a dentinal tubule penetration depth of 68–74 µm. PG mixed with suitable phosphoric acid agents has a short reaction time and a good operability that is feasible for occluding dentinal tubules. PG mixed with hardening agents has a greater potential for treating dentin hypersensitivity than PG without hardening agents.

Objectives The aim was to state the different applications and the effectiveness of polymeric zinc-doped nanoparticles to achieve dentin remineralization. Data, sources and study selection Literature search was conducted using electronic databases, such as PubMed, MEDLINE, DIMDI, Embase, Scopus and Web of Science. A narrative exploratory review was undertaken. Conclusions Polymeric nanospheres (NPs) were efficiently loaded with zinc. NPs sequestered calcium and phosphate in the presence of silicon, and remained effectively embedded at the hybrid layer. NPs incorporation did not alter bond strength and inhibited MMP-mediated dentin collagen degradation. Zn-loaded NPs remineralized the hybrid layer inducing a generalized low-carbonate substitute apatite precipitation, chemically crystalline with some amorphous components, and an increase in mechanical properties was also promoted. Viscoelastic analysis determined that dentin infiltrated with Zn-NPs released the stress by breaking the resin-dentin interface and creating specific mineral formations in response to the energy dissipation. Bacteria were scarcely encountered at the resin-dentin interface. The combined antibacterial and remineralizing effects, when Zn-NPs were applied, reduced biofilm formation. Zn-NPs application at both cervical and radicular dentin attained the lowest microleakage and also promoted durable sealing ability. The new zinc-based salt minerals generated covered the dentin surface totally occluding cracks, porosities and dentinal tubules. Clinical significance Zinc-doped NPs are proposed for effective dentin remineralization and tubular occlusion. This offers new strategies for regeneration of eroded cervical dentin, effective treatment of dentin hypersensitivity and in endodontically treated teeth previous to the canal filling. Zn-NPs also do reduce biofilm formation due to antibacterial properties.

The object of this study was to evaluate the effect of bioactive glass (BG) size on mineral formation on dentin surfaces. Totally demineralized dentin discs were treated using BG suspensions with different particle sizes: i.e. , microscale bioactive glass ( m -BG), submicroscale bioactive glass ( sm -BG) and nanoscale bioactive glass ( n -BG). Field-emission scanning electron microscopy and 3D profile measurement laser microscopy were used to observe the surface morphology and roughness. It was found that all BG particles could promoted mineral formation on dentin surfaces, while plug-like depositions were observed on the dentin discs treated by n -BG and they were more acid-resistant. The present results may imply that n -BG has potential clinical application for dentin hypersensitivity treatment.

To prevent the formation of caries and reduce dentin hypersensitivity, sealing materials, either with or without fluoride, are generally applied on the tooth in clinical practice. Application of fluoride-free sealing materials results in the formation of an acid-resistant layer on the tooth surface. On the other hand, fluoride-containing sealing materials might not only form an acid-resistant layer but could possibly further provide fluoride to enhance remineralization and reduce demineralization. In this study, the demineralization prevention ability and fluorine uptake rate in human enamel of fluoride-containing sealing materials [“MS coats F” (MSF)] and fluoride-free sealing materials (“hybrid coats 2” [HI]) were evaluated using an automatic pH cycling system. Each material was applied to the original tooth surface, the cut surfaces were covered with sticky wax, and the automatic pH-cycling system simulated daily acid changes (pH 6.8–4.5) occurring in the oral cavity for 4 weeks. Caries progression was analyzed using transverse microradiography (TMR) taken pre and post the 4 weeks of pH cycling. The fluorine and calcium distributions in the carious lesion in each specimen were evaluated using the proton-induced gamma emission (PIGE) and proton-induced X-ray (PIXE) techniques, respectively. TMR analysis showed that both MSF and HI had a caries-preventing effect after 4 weeks of pH cycling. PIGE/PIXE analysis demonstrated that only MSF resulted in fluoride uptake in the enamel surface. Therefore, MSF can help to form an acid-resistant layer and provide fluoride to the enamel surface. The presence of fluoride on the enamel surface suggested that MSF could prevent demineralization, even if the acid-resistant layer was removed, in clinical settings. The data obtained using the PIGE and PIXE techniques are useful for understanding the benefits of the use of a fluoride-containing sealing material for preventing caries.

Article Title and Bibliographic Information Effect of desensitizing toothpastes on dentine hypersensitivity: A systematic review and meta-analysis. Hu M-L, Zheng G, Zhang Y-D, Yan X, Li X–C, Lin H. J Dent (2018)75:12-21. SOURCE OF FUNDING The authors reported that this research did not receive any specific funding from the public, commercial, or not-for-profit sectors. TYPE OF STUDY/DESIGN Systematic review with meta-analysis of data.

Objective The aim of this split-mouth, triple-blind, randomized clinical trial was to evaluate the long-term clinical efficacy of experimental potassium oxalate concentration (10%) in relieving dentin hypersensitivity (DH), after a four-session application protocol. Methods Potassium oxalate gels with different concentrations (5 and 10%) were randomly assigned to half of the 31 patients from the sample in a split-mouth design. The desensitizers were applied following a four-session protocol, one session every 48 h. The primary outcome was the assessment of pain level with the visual analog scale (VAS, 0–10), at baseline, immediately after each desensitizing session, and also after the seventh day and along 1-,3-, 6-, 9- and 12-months follow-ups. Statistical analyses were performed using Friedman repeated measures and Wilcoxon signed rank tests (α = 0.05). Results For both groups, the minimum of three sessions were required for the achievement of lower DH levels. Regardless of the concentration, the desensitizing effect was maintained all the way to the end of the 6-month follow-up. The 10%-potassium oxalate group was more effective for both 9 and 12-months follow-up periods (p Conclusions When a four-session protocol is applied, both concentrations of potassium oxalate (5 and 10%) proved to be effective on DH reduction for up to six months. However, the higher concentration promoted better long-term results. Clinical Significance: The DH is an increasing condition in clinical practice, which affects the patient’s life quality. This study provides primary clinical evidence, suggesting that multiple application sessions and higher concentrations of potassium oxalate may result in maintenance of the desensitizing effect for more extended periods. Trial registered under number: ClinicalTrials.gov NCT03083496 .

Bioactive glass (BG) is a potential material for treating dentin hypersensitivity due to its high ability of dissolution. In this study, conventional BG and BG with well-ordered mesopore structures (MBG) were applied for dentinal tubule occlusion. We used X-ray diffractometer (XRD), scanning electronic microscope (SEM), and Fourier transform infrared (FTIR) to investigate the physiochemical properties and the dentinal tubule occlusion ability of BG and MBG groups. The results showed that the major crystallite phase of MBG and BG agents was monocalcium phosphate monohydrate. MBG pastes, mixed with 30 and 40 wt% phosphoric acid hardening solutions, had the ability to create a penetration depth greater than 50 μm. These results showed that BG with mesoporous structures turned the pastes mixed with suitable phosphoric acid solution into a material with great ability for occluding dentinal tubules; it has a short reaction time and good operability, and these agents have better potential for the treatment of dentin hypersensitivity than BG without mesoporous structures.

Background The prevalence of dentin hypersensitivity is uncertain, yet appropriate diagnosis and treatment of dentin hypersensitivity require accurate knowledge regarding its prevalence. The authors conducted a study to estimate the prevalence of dentin hypersensitivity in general dental practices and to investigate associated risk factors. Methods The authors conducted a cross-sectional survey of 787 adult patients from 37 general dental practices within Northwest Practice-based Research Collaborative in Evidence-based DENTistry (PRECEDENT). Dentin hypersensitivity was diagnosed by means of participants' responses to a question regarding pain in their teeth and gingivae, and practitioner-investigators conducted a clinical examination to rule out alternative causes of pain. Participants recorded their pain level on a visual analog scale and the Seattle Scales in response to a one-second air blast. The authors used generalized estimating equation log-linear models to estimate the prevalence and the prevalence ratios. Results The prevalence of dentin hypersensitivity was 12.3 percent; patients with hypersensitivity had, on average, 3.5 hypersensitive teeth. The prevalence of dentin hypersensitivity was higher among 18- to 44-year olds than among participants 65 years or older; it also was higher in women than in men, in participants with gingival recession than in those without gingival recession and in participants who underwent at-home tooth whitening than in those who did not. Hypersensitivity was not associated with obvious occlusal trauma, noncarious cervical lesions or aggressive toothbrushing habits. Conclusions One in eight participants from general practices had dentin hypersensitivity, which was a chronic condition causing intermittent, low-level pain. Patients with hypersensitivity were more likely to be younger, to be female and to have a high prevalence of gingival recession and at-home tooth whitening. Practical Implications Given dentin hypersensitivity's prevalence, clinicians should diagnose it only after investigating all other possible sources of pain.

This in vitro study evaluated the efficacy of bioglass (Denshield; Novamin Technology, Alachua, FL) and Neodymium-doped yttrium-aluminum-garnet (Nd:YAG) laser irradiation on dentinal tubuli orifice occlusion (DOO) by comparing samples examined under environmental scanning electron microscope (ESEM) after applying each desensitizing approach separately and in combination.Forty-eight human molars were collected, randomly organized in 4 equal groups, and had their cervical dentin exposed. Additionally, in half of the specimens of each experimental group, the smear layer was removed (subgroups A1, B1, C1, and D1). Group A received NovaMin paste treatment for 5 minutes (NM) to the experimental surface. Group B received Nd:YAG laser irradiation (0.5 w, 10 Hz, and 50 mJ) (L). Group C received NM followed by L. Group D was treated with L followed by NM. All specimens were stored for 24 hours and evaluated for DOO under ESEM by 4 blinded observers.The presence of a smear layer significantly contributed to DOO regardless of the treatment modality (ordinal logistic regression, P.001). Compared with group A, all other treatments delivered significantly more occluded dentin orifices (P.001 for groups B and D and P.05 for group C). A layer formation was observed in subgroups C2 and D2.Under these experimental conditions, a smear layer was essential for successful DOO. Laser irradiation alone and combined with NovaMin proved superior to NovaMin alone on DOO. This combined approach has the potential to improve the outcome of treatment for cervical dentin hypersensitivity. The biological significance of this newly formed layer needs to be elucidated.

Dentinal hypersensitivity is exemplified by brief, sharp, well-localized pain in response to thermal, evaporative, tactile, osmotic, or chemical stimuli that cannot be ascribed to any other form of dental defect or pathology. Pulpal pain is usually more prolonged, dull, aching, and poorly localized and lasts longer than the applied stimulus. Up to 30% of adults have dentinal hypersensitivity at some time. Current techniques for treatment may be only transient in nature and results are not always predictable. Two methods of treatment of dentin hypersensitivity are tubular occlusion and blockage of nerve activity. A differential diagnosis needs to be accomplished before any treatment.

Objectives: This study aimed to investigate the effects of using hydroxyl apatite functionalized calcium carbonate (FCC) particles on occluding dentinal tubules. Methods: Dentine specimens extracted from eighteen human molars with exposed dentinal tubules were divided into three groups (n = 6/group): a) Cut surface with smear layer; b) EDTA (smear layer removed with 17% EDTA for 1 min); and c) Grit blasted functionalized calcium carbonate (FCC) with and air pressure of 280 kPa. Microscopic dentinal tubule occlusion, tubule diameter and tubule area were evaluated using scanning electron microscopy (SEM) before and after grit blasting. Biomineralization of specimens was carried out in a simulated body fluid (SBF). Elemental analysis of occluding materials was carried out using energy-dispersive X-ray spectroscopy (EDX). X-ray diffraction (XRD) analysis was performed to demonstrate the crystal structure of the biomineralized layer on dentine. Results: FCC particles showed penetration into the dentinal tubules by breakage of their original particle shape and size. EDTA treated surface had higher number and larger size tubules than those with smear layer or grit blasted (p < 0.005). SEM-EDX analysis revealed mineral precipitation of calcium phosphate on the SBF immersed dentin specimens. XRD analysis showed typical crystal structure of hydroxyl apatite for the biomineralized surface layer on dentine. Conclusions: Grit blasted FCC particles initially occluded effectively the opened dentinal tubules and biomineralization occurred in tubules primarily occluded by the FCC particles. However, in the optimal in vitro conditions in SBF, no difference between biomineralization was found between the grit blasted surface and the control surface. Clinical significance: Several materials and methods have been established for treatment of dentinal hypersensitivity although a golden standard treatment has not been discovered. Grit blasted functionalized calcium carbonate has a potential to occlude and remineralize exposed dentinal tubules. This could offer a more biological approach on treatment of dentin hypersensitivity.

Background. Methods used by dental practitioners to diagnose and treat dentin hypersensitivity are not well documented. The authors conducted a survey of dentists in the Northwest Practice-based REsearch Collaborative in Evidence-based DENTistry (PRECEDENT) to ascertain the treatment methods they used. Methods. Via an Internet survey, the authors collected data regarding methods used for diagnosis and treatment of dentin hypersensitivity from 209 Northwest PRECEDENT dentists. Results. The PRECEDENT dentists indicated that they most often used fluoride varnishes and gels, advice regarding toothbrushing and diet, bonding agents, restorative materials and glutaraldehyde/2-hydroxyethyl methacrylate (HEMA) to treat dentin hypersensitivity. They reported that the most successful treatments were fluorides, glutaraldehyde/HEMA, bonding agents, potassium nitrates and restorative treatments; they considered observation, advice regarding toothbrushing and diet and laser therapy to be the least successful. Dentists listed fluorides, calcium phosphates, glutaraldehyde/HEMA and bonding agents as the treatments most desirable for inclusion in a future randomized clinical trial of dental hypersensitivity treatments. Conclusions. Dentists rely on patients to assess the severity of dentin hypersensitivity. Modalities for the diagnosis and treatment of hypersensitivity are diverse. Methods used to diagnose and treat dentin hypersensitivity in practice are challenging to justify. Clinical Implications. Practitioners should be aware of the diversity of methods available for diagnosing and treating dentin hypersensitivity as they manage the care of their patients with this condition.

Background NovaMin (NovaMin Technology, Alachua, Fla.) was introduced into the dental market as a desensitizer in December 2004. However, to the authors' knowledge, no researchers yet have evaluated the effectiveness of 100 percent NovaMin powder with NovaMin-containing toothpaste in reducing dentin hypersensitivity compared with the effectiveness of NovaMin-containing toothpaste only and a desensitizing toothpaste containing potassium nitrate as a control. Methods The authors divided 60 participants randomly into three groups: NovaMin powder with NovaMin-containing toothpaste (group 1), a placebo powder with NovaMin-containing toothpaste (group 2) and a placebo powder with the control toothpaste (group 3). The authors used tactile and cold stimuli and a visual analog scale to evaluate participants' pain at baseline, immediately after powder application and at one week, two weeks and four weeks after powder application. They analyzed data by using Friedman and Wilcoxon signed-rank tests for within-group comparison. They used Kruskal-Wallis and Mann-Whitney U tests for between-group comparison. They considered P Results Groups 1 and 2 showed significant hypersensitivity reduction over baseline at all time points. Group 3 showed significant hypersensitivity reduction at one week onward. Group 1 showed significant improvement compared with groups 2 and 3, except for response to tactile stimulus at four weeks with group 2. Between groups 2 and 3, there were significant differences at two and four weeks. Conclusions and Clinical Implications The use of NovaMin powder and NovaMin-containing toothpaste for hypersensitivity reduction is more effective than the use of a desensitizing toothpaste containing potassium nitrate and fluoride.

Background/purpose Many adults suffer from sensitivity, and dentin hypersensitivity is most commonly the result of exposed dentin which can sometimes trigger pain or discomfort when eating, drinking or simply brushing. The purpose of this study was to evaluate the clinical efficacy of desensitizing toothpaste containing potassium citrate in treating dentin hypersensitivity. Materials and methods This study was performed at the Department of Periodontics, Chung Shan Medical University Hospital. In total, 172 volunteers who provided informed consent were included in the study. A visual analog scale (VAS) was used to indicate dentin sensitivity in response to an air stimulus. Participants who had a VAS score of 30-80 were qualified for the study and were provided with their assigned desensitizing toothpaste containing potassium citrate (Colgate Sensitive Multi Protection) and a soft-bristled adult toothbrush for home use. After 4 weeks, the hypersensitive teeth were examined again, and the VAS score was also recorded. Results In this study, 38% (65/172) participants were found to suffer from dentin hypersensitivity, 40 persons who reported VAS scores of 30-80 were qualified for the clinical trial. Among these, 34 (85%) participants reported reduced dentin hypersensitivity after using the desensitizing toothpaste containing potassium cit-rate for 4 weeks. The mean value of the VAS score prior to the use of the toothpaste was 50.72, while the mean value of the VAS score after use was 30.68. The use of Colgate Sensitive Multi Protection was found to significantly reduce dentin hypersensitivity after 4 weeks (P Conclusion The prevalence of dentin hypersensitivity in this study was 38%. The use of desensitizing toothpaste containing potassium citrate with oral hygiene instruction can effectively reduce dentin hypersensitivity.

Introduction Various methods and materials are used in the treatment of dentin hypersensitivity. The aim of this randomized prospective controlled clinical trial was to evaluate and compare the desensitizing effects of the neodymium-doped yttrium aluminium garnet (Nd:YAG) laser and fluoride varnish by considering the degree of pre- and posttreatment pain, discomfort, and functional complications. Methods Twenty patients with clinically diagnosed cervical dentin hypersensitive teeth were included and randomly allocated to either the application of fluoride varnish (group fluoride) or Nd:YAG laser (100 mJ, 20 Hz; group Nd:YAG). The assessment of pain and discomfort was performed by a visual analog scale after an air blast at baseline, immediately after treatment, and at patient visits on weeks 1, 2, 3, and 4. Results Laser treatment resulted in significant improvements of discomfort immediately after treatment and after 1 week. At the 2-, 3-, and 4-week examination, the discomfort in group fluoride decreased up to nearly 75% to 85% of baseline scores, whereas the effect of the laser stayed nearly unchanged. The visual analog scale scores for pain at 4 weeks examination were significantly lower in the fluoride group compared with those in the laser group (p Conclusions Nd:YAG laser is a suitable tool for the immediately successful reduction of dentinal hypersensitivity and has better patient satisfaction and shorter treatment time.

The aim of this study was to evaluate the effect of an ozone delivery system (HealOzone; KaVo, Biberach, Germany) in reducing dentin hypersensitivity. An 8-week, 3-visit, triple-blinded, randomized controlled clinical trial with 2 HealOzone machines (ozone/air) involving 44 subjects was conducted. The pain in response to tactile stimulus or desiccation was assessed by using a 100-mm visual analogue scale. Also, the global subjects' perception of sensitivity was assessed at each visit by using the visual analogue scale. No subjects reported an increase in pain or any adverse effect. All subjects reported a clinically significant reduction of pain at each follow-up relative to baseline; however, the difference between the study groups was not statistically significant. The effect of treatment of hypersensitive teeth with ozone reduces the pain sensation, but this effect cannot be distinguished from the placebo treatment. There was a large placebo effect that narrowed the range over which to detect treatment differences.

Background The objective of this article was to review systematically the clinical trials of casein derivatives (specifically casein phosphopeptide–amorphous calcium phosphate [CPP-ACP] complex) used in dentistry. Types of Studies Reviewed The authors included clinical studies that examined the efficacy of casein derivatives in dentistry. They excluded in vitro studies, case series, case reports, letters to editors (not containing primary data), editorials, review articles and commentaries, but read them to identify any potential studies. Results The authors searched 98 articles for relevance, determined according to title, abstract and full text, resulting in a yield of 12 original studies. Nine were clinical trials that focused on caries prevention, seven of which showed that CPP-ACP (as found in sugar-free pellet or slab chewing gum, lozenges, milk or mouthrinse) was effective in preventing dental caries by remineralizing subsurface carious lesions in situ in a dose-response fashion. One was a clinical trial with conflicting results regarding the effect of CPP-ACP on the regression of white-spot lesions; one was a survey of the relief of dry-mouth symptoms; and one was an uncontrolled clinical study that showed the lack of effectiveness and lack of short-term therapeutic effect in treating dentin hypersensitivity. Clinical Implications The quantity and quality of clinical trial evidence are insufficient to make conclusions regarding the long-term effectiveness of casein derivatives, specifically CPP-ACP, in preventing caries in vivo and treating dentin hypersensitivity or dry mouth.

Objectives Dentin, a calcareous material sandwiched between the pulp and the enamel in the tooth structure contains highly orientated tubules. As a result of enamel erosion, gum recession, physical trauma or caries the dentin tubules can become patent to the oral cavity. It has been demonstrated in vivo that dentinal fluid flows out of the tubule lumen into the oral cavity and it has been postulated that alterations in fluid flow form the basis of dentin hypersensitivity. In order to better understand the mode of action of desensitising occlusion-based agents the ability to interrogate dentin non-destructively is paramount. Destructive analysis of the tooth structure may yield subtle artifacts leading to erroneous conclusions or inhibit the accurate assessment of the relationship between an occluding agent and the internal dentin morphology. This paper describes the use of a novel and accessible, non-invasive, high-focused X-ray computer tomographic technique for analysis of the dentin substructure. Methods Dentin slices, ca . 300 μm 3 in size, were taken from the coronal section of unerupted human third molars and etched in citric acid to reveal the open tubule structure. Samples were analyzed, in their dry state, using the Skyscan 2011 nanoCT system. Results Numerous, homogeneously dispersed elliptical features, distinguished by their contrast and hence low-mineral density, were observed. These features are observed to be approximately 2–5 μm in diameter at a density equivalent to 10 6 cm −2 . 2D CT re-slices demonstrate that these circular features form highly orientated cylindrical manifestations extending throughout the sample. Significance Ultra-high-resolution X-ray computed tomography has been shown to be a powerful new technique for interrogating the submicron tubular structure of dentin non-destructively.

Objective: To compare the clinical efficacy of the GaAlAs laser and dentin bonding agent in treating dentin hypersensitivity. Methods: One hundred and forty teeth from 70 patients diagnosed with dentin hypersensitivity, were divided into two groups: In group I, teeth were irradiated with 30 mW GaAlAs laser for 1 min and in group II, teeth were applied with dentin bonding agent. Sensitivity was assessed by tactile and thermal tests, measured with the criteria proposed by Uchida at baseline and after treatment; immediately, at 15 and at 30 days. Results: The reduction of dentin hypersensitivity was observed in both treatments using the GaAlAs laser and dentin bonding agent. However, a greater reduction was observed over time up to day 15 and no significant change was observed between days 15 and 30. Statistically significant differences in the level of dentin hypersensitivity between bonding agent and the GaAlAs laser were found at each observation period (p < 0.05). Conclusion: The GaAlAs laser had less desensitizing efficacy compared with dentin bonding agent. However, the desensitizing effect of the GaAlAs laser still could be considered an effective therapy for treating dentin hypersensitivity.

Diamine silver fluoride [AgF: (NH 3 ) 2 AgF] has been used clinically in Japan, as it reduces dental caries and dentin hypersensitivity. However, AgF stains the teeth black due to silver precipitation. To overcome this drawback, the authors prepared ammonium hexafluorosilicate [SiF: (NH 4 ) 2 SiF 6 ], which does not stain the teeth, and SiF occluded open dentin tubules completely with silica–calcium phosphate precipitate. Objectives The aim of this study was to evaluate the duration of dentin tubule occlusion after SiF treatment in a simulated oral environment. Methods To simulate dentin tubules subject to dentin hypersensitivity, dentin disks were treated with EDTA for 2 min. The disks were treated with 0.476 mol/L SiF for 3 min, and then the disks were immersed in synthetic saliva, which was regularly replenished to maintain its ionic concentration, for up to 7 days. The occluding ability of the dentin tubules was evaluated using scanning electron microscopy (SEM), and the hydraulic conductance was measured following Pashley's method at regular intervals. Results SEM photographs demonstrated that dentin tubules were occluded homogeneously and completely with the precipitate at 7 days after treatment with SiF. In addition, newly formed calcium phosphate precipitate was present at the dentin surface. The dentin permeability showed a consistently low value throughout the experimental period. The values immediately after SiF treatment and 7 days after immersion were 11.9 ± 3.7% and 7.9 ± 2.9%, respectively. Significance Ammonium hexafluorosilicate is useful for the treatment of dentin hypersensitivity, since ammonium hexafluorosilicate induced calcium phosphate precipitation from the saliva; therefore, it has a continuous effect on dentin tubules occlusion under a simulated oral environment.

DP-bioglass mixed with 30% phosphoric acid has been suggested to treat dentin hypersensitivity because the material is able to produce homogeneous occlusion of exposed dentinal tubules and is able to provide a sealing depth of up to 60 μm. The purpose of this study was to investigate the relative cytotoxic effect of the DP-bioglass paste, intermediate restorative material (IRM; DeTrey, Dentsply, Germany), and commercial desensitizing agent (Abmindent; Abmin Technologies Ltd, Turku, Finland) on human dental pulp cells by using a transwell insert model and a dentin-disc model. Cell viability was measured by means of a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The results of this study indicated that cell viability for the DP-bioglass paste did not differ significantly from those of the IRM or Abmindent in the transwell insert model. In addition, MTT results of DP-bioglass paste were similar to the control group in the dentin-disc model. The results indicated that DP-bioglass paste was a highly biocompatible material and could potentially serve as an effective material for treatment of dentin hypersensitivity.

Background This subject-blind randomized clinical trial tested the efficacy of a new 5 percent sodium fluoride varnish (AllSolutions Fluoride Varnish, Dentsply Professional, York, Pa.) for treatment of cervical dentin hypersensitivity. The authors also compared the test varnish with a control fluoride varnish (Duraphat, Colgate Oral Pharmaceuticals, New York City). Methods The study involved application of the test or control varnish to 19 subjects (59 teeth) with tooth sensitivity. The authors applied each product once to each tooth, following manufacturers' instructions. They used a visual analog scale (VAS) to assess subjects' responses to compressed air and ice stimuli at six weeks before baseline, at baseline and at two, eight and 24 weeks after treatment. Results Mean VAS scores for teeth receiving the test varnish dropped from 34.9 (air) and 68.0 (ice) at baseline to 26.3 (air) and 54.7 (ice) at two weeks after treatment. Mean scores at 24 weeks were 20.6 (air) and 34.8 (ice), representing statistically significant differences from baseline values. For the control varnish, mean VAS scores dropped from 36.9 (air) and 64.2 (ice) at baseline to 32.9 (air) and 47.2 (ice) at two weeks, and to 20.8 (air) and 40.3 (ice) at 24 weeks. The authors analyzed the data for statistical significance, accounting for clustering of teeth within subjects. Conclusion and Clinical Implications The test varnish was effective in reducing cervical dentin hypersensitivity. However, the efficacy was not significantly different from that of the control varnish.

The prevalence, distribution, and possible causal factors of cervical dentin hypersensitivity were studied in a population attending the Health Examination Center of National Taiwan University Hospital. A total of 780 patients were examined for the presence of cervical dentin hypersensitivity by means of a questionnaire and intraoral tests. There were 253 patients (32%) who claimed to have hypersensitive teeth at present and 90 patients (12%) who reported a history of hypersensitive teeth. The intraoral distribution of hypersensitivity showed that premolars and molars were the most common teeth sensitive to the air and probe stimuli, while the incisors were the least sensitive ones. The presence and history of dentin hypersensitivity were positively correlated with previous tooth-brushing and periodontal disease. Only a few of the patients who claimed to have dentin hypersensitivity had tried treatment with desensitizing tooth-pastes (11%) or sought professional help (5%).

Systematic review conclusion Current evidence does not support the routine use of oxalates—with the possible exception of 3 percent monohydrogen monopotassium oxalate alone—for the treatment of dentin hypersensitivity (DH) in adults. Critical summary assessment Results of this well-designed review and comprehensive analysis of the literature show, with the possible exception of 3 percent monohydrogen monopotassium oxalate alone, no significant difference in effectiveness between oxalates and placebo or no treatment in the treatment of DH. Evidence quality rating Limited.

Two independent reviewers screened the databases MEDLINE, EMBASE, the Cochrane Central Register of ControlledTrials, the National Research Register, and the Cochrane Oral HealthGroup'sTrials Register for articles written in English between 1977 and January1, 2010. The inclusion criteria comprised randomized controlled trials (RCTs) involving the application of laser desensitizing procedures and topical desensitizing agents in patients with at least 2 or more hypersensitive teeth confirmed by evaporative stimulus or tactile hypersensitivity assessment. Trial groups needed to receive laser therapy, whereas the control groups received topical desensitizing agents, such as fluoride varnish, dentin bonding agents, or others. Outcomes had to be measured by clinical performance (decrease of hypersensitivity) and/or patients' self-assessment. Studies with loss in follow-up greater than 20% or with confusing data/probable errors were excluded. A total of 176 potential relevant titles, abstracts, and articles were found, 28 of which were screened for further evaluation. Out of these, 8 trials met all inclusion criteria, involving a total of 234 patients. The quality of these trials was assessed according to the Cochrane Handbook for Systematic Reviews of Interventions. Accordingly, only 1 study was classified as A level, 5 as B level, and 2 as C level. A meta-analysis was not performed because of the heterogeneity of the studies.Studies that assess the application of laser desensitizing procedures in reducing dentinal hypersensitivity.The primary outcome was reduction of tooth sensitivity following treatment with either a laser or a topical desensitizing agent. Evaluations were made at varying intervals up to 6 months after treatment.Eight trials reporting on a total of 234 patients were included based on the specified criteria and 20 articles were excluded. Sample size in each of the included studies varied from 20 to 70 patients with differing follow-up intervals of up to 6 months. Most studies used Visual Analog Scale scores or other subjective tools to assess sensitivity. All 8 studies compared one kind of laser versus one kind of topical desensitizingagent. However, types of lasers as well as types of desensitizing agents differed among the reviewed studies. Half of the studies compared gallium-aluminum-arsenide (GaAlAs) lasers with various topical desensitizing agents; however, findings were conflicting. Two moderate-quality trials indicated that GaAlAs laser and the control desensitizing agents preformed similarly. Another moderate-quality trial demonstrated that the application of a bonding agent was significantly better than a GaAlAs laser in the reduction of hypersensitivity. The only reviewed study that was classified as an A-level study revealed a significantly greater immediate and long-term desensitizing effect than the control. The remaining studies involved Nd:YAG, Er:YAG, and CO(2) lasers, all of them reporting a slightly greater decrease in sensitivity as compared with topical desensitizing agents. Five of 8s tudies reported on the safety of laser application and did not find any detrimental pulpal effects, allergic reactions, or clinically detectable complications during follow-up.The authors concluded that the results obtained from the 8 studies included in this systematic review were conflicting but indicated a slight clinical advantage of laser therapy over topical medicaments in the treatment of dentin hypersensitivity. It was further concluded that application of lasers under controlled parameters for this indication may not lead to adverse effects.

One-hundred five teeth with clinically diagnosed cervical hypersensitive dentin were studied using scanning electron microscopy on replica models and electrical impedance. Thirty-two percent of the teeth were in male patients in their 40s. Maxillary premolars comprised 31%; maxillary incisors, 27%; mandibular premolars, 17%; and mandibular incisors, 15%. Scanning electron microscopy of the models of hypersensitive spots showed enlarged dentinal tubules, agglutinated dentinal tubules, belt-like groups of agglutinated dentinal tubules, and tubule morphology not clearly visible. The electrical impedance of the cervical hypersensitive dentin ranged from 15 to 150 ohms, with an average of 54 ohms. There was a significantly high correlation between the dentinal tubule morphology and dentin hypersensitivity.