A randomised controlled trial evaluating the impact of oral health advice on gingival health using intra oral images combined with a gingivitis specific toothpaste.

OBJECTIVES: Does a complex intervention of oral hygiene advice (OHA) delivered with intra-oral scanner images, anti-gingivitis toothpaste and motivational reminders, improve oral health more than a standard of care control arm of fluoride toothpaste, with OHA without scanner images? METHODS: Adult participants with pre-existing gingivitis were randomised to intervention or control. Following enrolment, baseline and each subsequent visit (V) (3-weeks, V2; 3-months, V3; 6-months, V4) followed the same schedule. Bleeding on Probing (BOP) was assessed and Intra Oral Scan IOS(1) recorded. Plaque was disclosed, scored and re-scanned (IOS(2)). The intervention group received OHA with IOS images, control group receiving OHA without IOS images. Participants brushed with their allocated toothpaste (fluoride, control; anti-gingivitis, intervention), IOS(3) was recorded. Between visits participants brushed with their allocated toothpaste, intervention group received motivational reminders. RESULTS: BOP scores from baseline were significantly improved in the intervention group compared to control at all visits for all surfaces (p<0.001); differences at V4 were 0.292 (all), 0.211 (buccal/labial) and 0.375 (lingual/palatal). Plaque scores from baseline pre-brushing to each visit pre- and post-brushing also favoured the intervention group, the difference always significant on lingual/palatal surfaces (p<0.05), significant for all but pre-brushing-V4 (p<0.05) on all surfaces, but only significant for pre-brushing-V3 (p<0.05) buccally/labially. Differences from baseline to post-brushing at V4 were: 0.200 (all), 0.098 (buccal/labial) and 0.291 (lingual/palatal). CONCLUSION: A complex intervention comprising OHA delivered with IOS-images, anti-gingivitis toothpaste and motivational reminders improved gingival health more than existing standard of care-OHA together with a standard fluoride toothpaste over a 6-month period. CLINICAL SIGNIFICANCE STATEMENT: Intra-oral scans (IOS) are now frequently used in general dental practice for a variety of purposes. IOS use, in combination with motivational texts and an anti-gingivitis toothpaste, could be further deployed to promote oral hygiene behaviour change in patients and improve gingival health, in a cost-effective manner.

Antigingivitis efficacy of a sodium bicarbonate toothpaste: Pooled analysis.

OBJECTIVE: The objective of this study was to investigate the antigingivitis and antiplaque treatment effect of a toothpaste containing 67% w/w sodium bicarbonate, at the individual tooth site, tooth region and whole mouth (overall) level, by way of a pooled analysis of data from similarly designed clinical trials. METHODS: Six randomized controlled GSKCH clinical trials, 12-24 weeks in duration, were selected based on pre-specified criteria which included access to patient level data, pre-treatment dental prophylaxis, >20 bleeding sites and mild-moderate gingivitis at screening and use of 67% sodium bicarbonate toothpaste and non-sodium bicarbonate (regular) toothpaste (negative control) for ≥4 weeks. Efficacy outcomes comprised plaque index (TPI), modified gingival index (MGI) and gingival bleeding (bleeding index (BI), number of bleeding sites (BS)). Treatment comparisons were made using ANCOVA for whole mouth (overall) scores and by tooth site region (facial overall, lingual overall; margin/body overall, facial margin/body, lingual margin/body; papillae/interproximal overall, facial papillae/interproximal, lingual papillae/interproximal). Pooled data for BI, MGI, and TPI at individual tooth sites was plotted as a mouthmap to summarize treatment response (change from baseline) by tooth site, at the 24-week timepoint. RESULTS: For all measures, whole mouth and for all tooth regions at all post-treatment timepoints, significant (p < 0.001) differences in favour of the 67% sodium bicarbonate toothpaste compared with control were observed. At the 24-week timepoint, facial regions demonstrated greater improvements than lingual regions, with the greatest between treatment improvement seen for the facial-papillae regions for bleeding (BS/BI), facial-margin regions for MGI and facial-body regions for TPI. All individual tooth sites demonstrated numerically greater reductions from baseline for the 67% sodium bicarbonate toothpaste than the control toothpaste following 24 weeks use, with the greatest improvements (change from baseline) seen for posterior and papillae tooth sites for bleeding, margin tooth sites for MGI and body tooth sites for TPI. CONCLUSION: This pooled analysis of patient level-data, limited to GSKCH long-term gingivitis clinical studies, demonstrates that twice daily use of a 67% sodium bicarbonate toothpaste effectively removes plaque from all tooth sites, and results in clinically significant improvements in measures of gingival health, overall and for all the tooth regions investigated, compared with a non-sodium bicarbonate (regular) toothpaste following 24 weeks twice daily use.

A proof of concept study to confirm the suitability of an intra oral scanner to record oral images for the non-invasive assessment of gingival inflammation.

OBJECTIVES: To compare gingival inflammation scores obtained chairside using the non-invasive modified gingival index (MGI) with MGI scores from an intraoral scan (IOS) captured at the clinical visit but viewed 10 days later. METHODS: Single visit, anterior teeth, observational, proof of concept study in healthy adult participants with a spectrum of gingival inflammation. One investigator performed both clinical and intraoral scan MGI assessments, a second repeated the MGI evaluation from the IOS. RESULTS: 23 participants aged 18-72 yielded data for 552 gingival sites. There was agreement at 90 % of sites comparing clinical with IOS MGI scores. The commonest disagreements were MGI grade 0 read as 1 and 2 read as 3, the highest single probability of error occurring where a clinical score of 0 was scored 1 from the IOS: 0.118 and 0.129 for examiners 1 and 2 respectively. The second most common probability of error occurred where an IOS score of 3 was scored clinically as 2: 0.089 and 0.097 for examiners 1 and 2 respectively. MGI scores from the scans were similar for both examiners (91 % agreement), with no discrepancies of greater than 1 scale point. There was very close agreement between clinical MGI and IOS colour/texture scores. CONCLUSION: This study conclusively demonstrated that the MGI score from the scanned image was very similar to the MGI scored clinically. This study confirms that a digital IOS accurately captures gingival contour images allowing a clinician to determine health or degree of gingival inflammation from it using MGI scores. CLINICAL SIGNIFICANCE STATEMENT: This study confirms that IOS images of teeth and soft tissues are sufficiently accurate to allow the clinical evaluation of health or inflammatory gingival status using non-invasive indices. IOS has great potential for efficient and accurate data capture, for general practice and research facilitating remote evaluation and data verification.

Randomised study of intra-oral kinetics of fluoride-containing toothpastes.

OBJECTIVES: This randomised, controlled, analyst blind, crossover study aimed to evaluate and compare salivary fluoride and calcium ion concentration over 60 min following brushing with an assigned treatment and following an orange juice (OJ) or deionised (DI) water rinse 60 min post-brushing. METHODS: Study treatments, both containing 1150 ppm fluoride as NaF and 5% w/w KNO3, were the Test (including 1.2 % w/w cocamidopropyl betaine) and Comparator (including tetrasodium pyrophosphate and sodium lauryl sulphate) toothpastes. Twenty nine participants were randomised to treatment. RESULTS: A sharp increase in salivary fluoride ion concentration immediately post-brushing with either toothpaste decreased over time. Fluoride concentration following Test toothpaste use was numerically higher than the Comparator at all timepoints, with a significant difference from 10 min post-brushing (p < .05). Following the 60 min rinse, there were no significant differences between the Test or Comparator + OJ groups in salivary fluoride concentration but the Test + DI water group was significantly lower than Test (p < .001) or Comparator (p < .001) + OJ groups. A reduction in salivary calcium ion concentration was seen immediately post-brushing and after the OJ rinse with both toothpastes. Significant differences were observed in favour of the Test toothpaste at all timepoints (p < .05) and for Test and Comparator + OJ group (p < .001) compared with Test + DI water rinse. Both treatments were generally well-tolerated. CONCLUSIONS: This study demonstrated that toothpaste formulations with identical declared fluoride concentrations and the same fluoride source give rise to differing intraoral fluoride concentrations over time, which are potentially related to different formulation excipient effects. CLINICAL SIGNIFICANCE: By understanding the interaction of toothpaste formulation excipients in the oral environment, formulations can be developed that maximise retention of fluoride in the oral environment.

A randomised oral fluoride retention study comparing intra-oral kinetics of fluoride-containing dentifrices before and after dietary acid exposure.

OBJECTIVE: This exploratory, randomised, single-blind, crossover, study evaluated fluoride and calcium ion concentrations and pH following use of one of two 1450 ppm fluoride (NaF), 5% w/w KNO3 dentifrices: (1) test dentifrice (with cocamidopropyl betaine) with an orange juice (OJ) rinse; (2) test dentifrice with a deionized (DI) water rinse or (3) comparator dentifrice (with sodium lauryl sulphate and tetrasodium pyrophosphate) with an OJ rinse. DESIGN: Eighteen participants used their assigned dentifrice, rinsed with DI water, then expectorate was collected. Sixty min post-brushing, participants rinsed with OJ or DI water then expectorate was collected. Saliva samples were collected pre-brushing and at 1, 5, 10, 15, 30 and 60 min post-brushing and following the 60 min OJ/DI water rinse. The pH of samples was taken. RESULTS: Significant differences (p < 0.05) were found in salivary fluoride ion concentrations between test and comparator dentifrices at 30 and 60 min and following the 60 min OJ rinse, favouring the former. Significant differences were also found between test and comparator dentifrices for salivary calcium ion concentration at 1, 5 and 10 min (p < 0.0001), favouring the former, and between test or comparator + OJ rinse and test + water rinse (p < 0.005), favouring the latter. No pH differences were shown prior to OJ/water rinse. Products were generally well-tolerated. CONCLUSIONS: Results confirmed that acid-labile fluoride is released from the oral cavity following a dietary acid challenge and showed that formulation excipients may impact on retention of such.

Dentin hypersensitivity monitored by cold air quantitative sensory testing.

BACKGROUND: Quantification of dentin hypersensitivity (DH) is challenging and requires standardised, graded stimulation by natural-like stimuli. OBJECTIVE: The present study aimed at identifying DH subjects and longitudinally monitoring their pain thresholds by cold air quantitative sensory testing (QST). METHODS: Subject recruitment started with an online DH questionnaire. Respondents were screened by dental air stimulation. Sensitising and habituating subjects were excluded. A recently developed stimulation device was employed for cold air QST. Single tooth DH was verified by applying an equi-intense stimulus to a control tooth. Descriptive statistics were applied for subject characteristics. Mean values were calculated for the stimulation parameters temperature and air flow. Reliability of temperatures for detecting pain and for evoking moderate pain over multiple time points within a 3-week period was analysed by two-way random single- and average-measure intra-class correlation coefficients. RESULTS: A total of 353 persons completed the online DH questionnaire of which 117 were screened. Forty-four passed the screening, yet 15 were excluded for various reasons. Twenty-nine subjects were monitored by QST across 3 weeks. Results revealed a high intra-individual stability of the temperature inducing moderate to strong pain intensity (MPI) (single-measure ICC of TMPI 0.83, P < 0.001). Mean TMPI was -13.69°C, yet it highly varied among the 29 subjects (SD ± 10.04°C). CONCLUSIONS: Using a novel approach, namely dental QST based on cold air stimuli, we present evidence for temporally stable DH perceptions over a 3-week period. The method fulfils international guideline requirements and is recommendable for obtaining valid results when testing various interventions for DH management.

A 12-week randomized clinical study investigating the anti-gingivitis efficacy of a 0.454% w/w stannous fluoride dentifrice.

PURPOSE: To evaluate and compare gingival health, as measured by a bleeding index (BI), a modified gingival index (MGI), number of bleeding sites, and blood in expectorate following twice daily use of a non-aqueous 0.454% weight/weight (w/w) stannous fluoride dentifrice ('Test dentifrice') compared to a sodium monofluorophosphate (SMFP) dentifrice (' Negative Control') over 12 weeks, in subjects with moderate gingivitis and gingival bleeding following tooth brushing. METHODS: This was a single-center, examiner-blinded, randomized, stratified, two-treatment arm, parallel group, 12-week clinical study in healthy adult volunteers with moderate gingivitis who demonstrated gingival bleeding following tooth brushing. Subjects were assessed at baseline for MGI, visible blood in dentifrice expectorate and BI. Following randomization, eligible subjects underwent a thorough dental prophylaxis and flossing. After 4 and 12 weeks of twice daily brushing with their allocated treatment, subjects returned to the site for MGI, visible blood in dentifrice expectorate, and BI assessments. RESULTS: Of 317 screened subjects, 253 were randomized, and 238 completed the study. Statistically significant differences between treatments were observed in favor of the Test dentifrice compared to the Negative Control dentifrice in terms of gingival bleeding (number of bleeding sites and bleeding index), and visual signs of gingival inflammation (MGI) (P< 0.0001 at Weeks 4 and 12 for all). The visual assessment of the level of blood in expectorate following brushing demonstrated large reductions from baseline, however no significant difference between treatments was observed. Treatments were generally well tolerated. CLINICAL SIGNIFICANCE: Use of a dentifrice containing 0.454% w/w stannous fluoride led to significantly greater control of gingivitis (gingival bleeding and visual signs of gingival inflammation) compared to a SMFP dentifrice over a 12-week period. This study was conducted in subjects with moderate gingivitis and in a population represented by individuals who experience gingival bleeding on brushing, and is therefore considered representative of individuals who may opt for treatment therapies in the form of a daily use toothpaste.

A 24-week randomized clinical study investigating the anti-gingivitis efficacy of a 0.454% w%#47;w stannous fluoride dentifrice.

PURPOSE: To evaluate and compare gingival health, as measured by a bleeding index (BI), a modified gingival index (MGI), a dental plaque index (PI), and number of bleeding sites following twice daily use of an anhydrous 0.454% weight/weight (w/w) stannous fluoride dentifrice (Test Dentifrice) compared to a sodium monofluorophosphate (SMFP) dentifrice (Negative Control) over 24 weeks. METHODS: This was a single-center, examiner-blinded, randomized [by gender and baseline mean MGI score (Low ≤ 2.00/High > 2.00)], stratified, two-treatment arm, parallel group, 24-week clinical study in healthy adult volunteers with moderate gingivitis. At baseline, after abstaining from toothbrushing overnight, subjects underwent BI, MGI and PI assessments. Following randomization, eligible subjects underwent a thorough dental prophylaxis and flossing. After 12 and 24 weeks of twice daily brushing with their allocated treatment, subjects returned to the site with overnight plaque (having abstained from oral hygiene procedures for at least 8 hours) for BI, MGI and PI assessments. RESULTS: Of 109 screened subjects, 104 were randomized and 98 completed the study. Statistically significant differences between treatments were observed in favor of the Test Dentifrice compared to the Negative Control dentifrice for all outcome measures including not only BI, MGI and PI indices but also number of bleeding sites (P< 0.0001 at Week 12 and Week 24 for all). Data observation showed that the percentage of sites that decreased was more, and those that increased was less, with the Test Dentifrice than with the Negative Control dentifrice at both 12 and 24 weeks. Treatments were generally well tolerated. CLINICAL SIGNIFICANCE: Use of a dentifrice containing 0.454% w/w stannous fluoride led to significantly greater control of gingivitis (gingival bleeding and visual signs of gingival inflammation) and plaque compared to a SMFP dentifrice over a 24-week period.

Effect of phytate and zinc ions on fluoride toothpaste efficacy using an in situ caries model.

OBJECTIVES: To compare and explore the dose-response of phytate-containing 1150 ppm fluoride toothpastes on model caries lesions and to determine the impact of zinc ions. METHODS: This was a single-centre, randomised, blinded (examiner/laboratory analyst), six-treatment, four-period crossover, in situ study in adults with a removable bilateral maxillary partial denture. Study treatments were toothpastes containing: 0.425% phytate/F; 0.85% phytate/F; 0.85% phytate/Zn/F; F-only; Zn/F and a 0% F placebo. Where present, F was 1150 ppm as NaF; Zn was 0.3% as ZnCl2. Human enamel specimens containing early-stage, surface-softened (A-lesions) or more advanced, subsurface (B-lesions) caries lesions were placed into the buccal flanges of participants' modified partial denture (one of each lesion type per side). A-lesions were removed after 14 days of twice-daily treatment use; B-lesions were removed after a further 14 days. A-lesions were analysed for surface microhardness recovery. Both lesion types were analysed by transverse microradiography and for enamel fluoride uptake, with B-lesions additionally analysed by quantitative light-induced fluorescence. Comparison was carried out using an analysis of covariance model. RESULTS: Statistically significant differences between 1150 ppm F and the placebo toothpastes (p < 0.05) were shown for all measures, validating the model. No differences between fluoride toothpastes were observed for any measure with little evidence of a dose-response for phytate. Study treatments were generally well-tolerated. CONCLUSIONS: Results suggest phytate has little impact on fluoride's ability to promote early-stage lesion remineralisation or prevent more advanced lesion demineralisation in this in situ caries model. Similarly, results suggest zinc ions do not impair fluoride efficacy. CLINICAL SIGNIFICANCE: Toothpastes may contain therapeutic or cosmetic agents that could interfere with fluoride's caries prevention efficacy. The present in situ caries study has demonstrated that phytate, added to provide enhanced extrinsic stain removal/prevention, and zinc, added to inhibit malodour, do not impair fluoride efficacy.

Effects of a sodium fluoride- and phytate-containing dentifrice on remineralisation of enamel erosive lesions-an in situ randomised clinical study.

OBJECTIVE: The objective of this work was to evaluate effects of a dentifrice containing sodium fluoride (1150 ppm F) and the organic polyphosphate phytate (0.85% w/w of the hexa-sodium salt) on in situ remineralisation of early enamel erosive lesions and resistance to subsequent demineralisation. MATERIALS AND METHODS: Subjects (n = 62) wore palatal appliances holding eight bovine enamel specimens with pre-formed erosive lesions. They brushed their natural teeth with the phytate test dentifrice (TD); a positive control dentifrice (PC, 1150 ppm fluoride as NaF); a reference dentifrice (RD, disodium pyrophosphate + 1100 ppm fluoride as NaF) or a negative control dentifrice (NC, fluoride-free) in a randomised, double-blind, crossover design. Specimens were removed at 2, 4 and 8 h post-brushing and exposed to an ex vivo acid challenge. Surface microhardness (Knoop) was measured at each stage. The primary efficacy variable was relative erosion resistance (RER); other variables included the surface microhardness recovery (SMHR), acid resistance ratio (ARR) and enamel fluoride uptake (EFU). RESULTS: After 4 h, the results for RER, ARR and EFU were in the order PC > TD = RD > NC with PC > TD = RD = NC for SMHR. Results at 2 and 8 h were generally consistent with the 4 h data. Mineralisation progressed over time. Dentifrices were generally well-tolerated. CONCLUSIONS: In this in situ model, addition of phytate or pyrophosphate to a fluoride dentifrice inhibited the remineralising effect of fluoride. Both formulations still delivered fluoride to the enamel and inhibited demineralisation, albeit to a lesser extent than a polyphosphate-free dentifrice. CLINICAL RELEVANCE: Addition of phytate or pyrophosphate to a fluoride dentifrice may reduce its net anti-erosive properties.

A randomised clinical evaluation of a fluoride mouthrinse and dentifrice in an in situ caries model.

OBJECTIVES: Fluoride mouthrinses provide advantages for fluoride delivery by maintaining elevated intra-oral fluoride concentrations following fluoride dentifrice use. This in situ caries study investigated potential anti-caries efficacy of a 220 ppm fluoride mouthrinse. METHODS: This was an analyst-blinded, four-treatment, randomised, crossover study using partially demineralised, gauze-wrapped, human enamel samples mounted in a mandibular partial denture. Participants brushed twice daily for 14 days with either a 1150 ppm fluoride or a fluoride-free placebo dentifrice and either rinsed once daily with the 220 ppm fluoride mouthrinse or not. Following each treatment period, percent surface microhardness recovery (%SMHR) and enamel fluoride uptake (EFU) were assessed. RESULTS: Fifty three participants completed the study. Compared with the placebo dentifrice/no rinse treatment, the fluoride-containing regimens demonstrated greater enamel remineralisation (%SMHR) and fluoridation (EFU): fluoride dentifrice/fluoride rinse (%SMHR difference: 21.55 [95% CI: 15.78,27.32]; EFU difference 8.35 [7.21,9.29]); fluoride dentifrice/no rinse: 19.48 [13.81,25.15]; 6.47 [5.35,7.60]; placebo dentifrice/fluoride rinse: 16.76 [11.06,22.45]; 5.87 [4.72,7.00] (all P < .0001). There were no significant differences in%SMHR between fluoride regimens. The fluoride dentifrice/fluoride rinse regimen was associated with higher EFU than the fluoride dentifrice/no rinse (1.88 [0.75,3.01], P = .0013) and placebo dentifrice/fluoride rinse regimens (2.48 [1.34,3.62], P < .0001). Treatments were generally well-tolerated. CONCLUSIONS: The in situ caries model demonstrated that the fluoride mouthrinse is effective in promoting enamel caries lesion remineralisation and fluoridation whether used following a fluoride or non-fluoride dentifrice. Additive (potential) anti-caries benefits of a fluoride rinse after a fluoride dentifrice were confined to enhancements in lesion fluoridation (EFU). CLINICAL SIGNIFICANCE: In conjunction with a fluoride dentifrice, fluoride mouthrinses enhance enamel fluoridation, which may be useful in caries prevention.

An in-situ pilot study to investigate the native clinical resistance of enamel to erosion.

OBJECTIVES: To investigate the differences in susceptibility of the surface of native and polished enamel to dietary erosion using an in-situ model. METHODS: Thirty healthy volunteers (n = 10 per group) wore mandibular appliances containing 2 native and 2 polished enamel samples for 30 min after which, the samples were exposed to either an ex-vivo or in-vivo immersion in orange juice for 5, 10 or 15 min and the cycle repeated twice with an hour's interval between them. Samples were scanned with a non-contacting laser profilometer and surface roughness was extracted from the data, together with step height and microhardness change on the polished enamel samples. RESULTS: All volunteers completed the study. For native enamel there were no statistical difference between baseline roughness values versus post erosion. Polished enamel significantly increased mean (SD) Sa roughness from baseline for each group resulting in roughness change of 0.04 (0.03), 0.06 (0.04), 0.04 (0.03), 0.06 (0.03), 0.08 (0.05) and 0.09 (0.05) µm respectively. With statistical differences between roughness change 45 min in-vivo versus 45 min ex-vivo (p < 0.05). Microhardness significantly decreased for each polished group, with statistical differences in hardness change between 30 min in-vivo versus 30 min ex-vivo (p < 0.05), 45 min in-vivo versus 30 min ex-vivo (p < 0.01), 45 min in-vivo versus 45 min ex-vivo (p < 0.01). CONCLUSIONS: The native resistance to erosion provided clinically is a combination of the ultrastructure of outer enamel, protection from the salivary pellicle and the overall effects of the oral environment. CLINICALTRIALS. GOV IDENTIFIER: NCT03178968. CLINICAL SIGNIFICANCE: This study demonstrates that outer enamel is innately more resistant to erosion which is clinically relevant as once there has been structural breakdown at this level the effects of erosive wear will be accelerated.

Randomised clinical trial to evaluate changes in dentine tubule occlusion following 4 weeks use of an occluding toothpaste.

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

Randomized Clinical Dose-Response Study to Evaluate Plaque Removal by Three Experimental Sodium Bicarbonate Toothpastes Using a Single Brushing Model.

OBJECTIVES: This randomized, examiner-blind, crossover clinical study compared the plaque removal efficacy of three experimental toothpastes containing 20%, 35%, and 50% w/w sodium bicarbonate (NaHCO3) with commercial toothpastes containing 67% and 0% w/w NaHCO3 (positive and negative controls, respectively). METHODS: Fifty-six adults with a mean Turesky Modification of the Quigley-Hein Plaque Index (TPI) score of = 2.00 at screening and at the first treatment visit (pre-brushing) were randomized to a supervised single, timed (one minute) brushing with a 0%, 20%, 35%, 50%, or 67% w/w NaHCO3-containingtoothpaste. TPI was measured pre- and post-brushing. Participants completed five treatment visits, separated by a four- to six-day washout, and brushed once with each toothpaste. The primary efficacy analysis was change in whole mouth TPI score from pre- to post-brushing between the positive and negative control toothpastes (validation step). Secondary analyses were comparisons between each experimental toothpaste and the control toothpastes. Change in TPI score was analyzed using a mixed effect analysis of covariance. RESULTS: The difference in adjusted mean TPI change from pre- to post-brushing between the 67% and 0% w/w NaHCO3 toothpastes was -0.01 points (95% CI -0.06, 0.04), with no statistically significant difference between them (p = 0.6674). As such, study validity was not attained. Differences in adjusted mean change from pre- to post-brushing between each experimental toothpaste and the positive and negative controls ranged from 0.00 to -0.02 points. Twenty-two treatment-emergent, treatment-related adverse events, all oral, were reported by 17 participants (30.4%). These were spread uniformly across test toothpastes and controls. No serious adverse events were reported. CONCLUSIONS: There was no statistically significant difference in change in mean TPI score between toothpastes containing 67% w/w NaHCO3 and 0% w/w NaHCO3 following a single timed brushing. This unexpected observation may be attributed to lower than expected reduction in overall plaque and a possible Hawthorne effect. As study validation was not met, no further conclusions can be made. The study products were generally well tolerated.

Measurement of surface roughness changes of unpolished and polished enamel following erosion.

OBJECTIVES: To determine if Sa roughness data from measuring one central location of unpolished and polished enamel were representative of the overall surfaces before and after erosion. METHODS: Twenty human enamel sections (4x4 mm) were embedded in bis-acryl composite and randomised to either a native or polishing enamel preparation protocol. Enamel samples were subjected to an acid challenge (15 minutes 100 mL orange juice, pH 3.2, titratable acidity 41.3mmol OH/L, 62.5 rpm agitation, repeated for three cycles). Median (IQR) surface roughness [Sa] was measured at baseline and after erosion from both a centralised cluster and four peripheral clusters. Within each cluster, five smaller areas (0.04 mm2) provided the Sa roughness data. RESULTS: For both unpolished and polished enamel samples there were no significant differences between measuring one central cluster or four peripheral clusters, before and after erosion. For unpolished enamel the single central cluster had a median (IQR) Sa roughness of 1.45 (2.58) µm and the four peripheral clusters had a median (IQR) of 1.32 (4.86) µm before erosion; after erosion there were statistically significant reductions to 0.38 (0.35) µm and 0.34 (0.49) µm respectively (p<0.0001). Polished enamel had a median (IQR) Sa roughness 0.04 (0.17) µm for the single central cluster and 0.05 (0.15) µm for the four peripheral clusters which statistically significantly increased after erosion to 0.27 (0.08) µm for both (p<0.0001). CONCLUSION: Measuring one central cluster of unpolished and polished enamel was representative of the overall enamel surface roughness, before and after erosion.

Randomized Controlled Trial to Explore the Effect of Experimental Low Abrasivity Dentifrices on Enamel Gloss and Smoothness, and the Build-up of Extrinsic Tooth Stain.

OBJECTIVES: To evaluate and compare examiner-assessed changes in enamel gloss, extrinsic dental stain, and surface smoothness following one, two, four, and eight weeks of twice-daily use of an experimental low abrasivity desensitizing dentifrice (relative dentin abrasivity [RDA] ~40) containing 5% sodium tripolyphosphate (STP) chemical cleaning agent and 1% aluminum trioxide abrasive. This was compared with an ultra-low abrasivity dentifrice (5% STP only; RDA ~13), a moderate abrasivity fluoride dentifrice (RDA ~80), and a higher abrasivity marketed whitening dentifrice (RDA ~142). METHODS: This was a single-center, examiner-blind, randomized, controlled, parallel group study in healthy adults stratified by gloss score and age. Following a washout period with a conventional silica abrasive dentifrice, subjects received a dental scale and polish and were randomized to treatment. Subjects brushed their teeth for two minutes, twice daily, with their assigned dentifrice. Enamel gloss was assessed visually by comparing the facial surfaces of the maxillary incisors to the Sturzenberger gloss standards. Extrinsic dental stain was measured on the 12 anterior teeth (facial and lingual) using the Macpherson modification of the Lobene Stain Index (MLSI). Tooth smoothness was assessed using scanning electron microscope (SEM) analysis of a silicone impression of the central incisors. RESULTS: Of 120 screened subjects, 95 were randomized to the study. Subjects using the low abrasivity aluminum trioxide/STP dentifrice demonstrated statistically significant (p < 0.05) and increasing improvements in surface gloss over baseline at all time points, with a significant treatment effect compared to all other study dentifrices from Week 2 (p < 0.05). With respect to dental stain, the low abrasivity dentifrice group had the lowest stain score at each post-treatment time point and demonstrated statistically significantly less stain compared to all study dentifrices at Weeks 2 (p < 0.05) and 8 (p < 0.01). For tooth smoothness, at Week 8, statistically significant increases in surface smoothness were observed for most treatment groups compared to baseline (p < 0.05), except for the moderate abrasivity dentifrice. CONCLUSIONS: This study shows the benefit of a low abrasivity dentifrice containing STP and aluminum trioxide in reducing stain build-up and increasing tooth gloss compared to a non-alumina ultra-low abrasivity STP-containing dentifrice, and moderate and high abrasivity dentifrices, over an eight-week period.

Anticaries Potential of a Sodium Monofluorophosphate Dentifrice Containing Calcium Sodium Phosphosilicate: Exploratory in situ Randomized Trial.

Calcium sodium phosphosilicate (CSPS) is a bioactive glass material that alleviates dentin hypersensitivity and is postulated to confer remineralization of caries lesions. This single-centre, randomized, single (investigator)-blind, placebo-controlled, crossover, in situ study explored whether the addition of 5% CSPS to a nonaqueous fluoride (F) such as sodium monofluorophosphate (SMFP)-containing dentifrice affects its cariostatic ability. Seventy-seven subjects wore 4 gauze-covered enamel specimens with preformed lesions (2 surface-softened and 2 subsurface) placed buccally on their mandibular bilateral dentures for up to 4 weeks. Subjects brushed twice daily with 1 of the 5 study dentifrices: 927 ppm F/5% CSPS, 927 ppm F/0% CSPS, 250 ppm F/0% CSPS, 0 ppm F/5% CSPS, or 0 ppm F/0% CSPS. Specimens were retrieved after either 21 (surface-softened lesions; analyzed by Knoop surface microhardness [SMH]) or 28 days (subsurface lesions; analyzed by transverse microradiography). The enamel fluoride uptake was determined for all specimens using a microbiopsy technique. The concentrations of fluoride and calcium in gauze-retrieved plaque were also evaluated. Higher dentifrice fluoride concentrations led to greater remineralization and fluoridation of both lesion types and increased plaque fluoride concentrations. CSPS did not improve the cariostatic properties of SMFP; there were no statistically significant differences between 927 ppm F/5% CSPS and 927 ppm F/0% CSPS in percent SMH recovery (p = 0.6788), change in integrated mineral loss (p = 0.5908), or lesion depth (p = 0.6622). Likewise, 0 ppm F/5% CSPS did not provide any benefits in comparison to 0 ppm F/0% CSPS. In conclusion, CSPS does not negatively impact nor does it improve the ability of an SMFP dentifrice to affect remineralization of caries lesions.

T2 relaxation mapping MRI of healthy and inflamed gingival tissue.

OBJECTIVES: To investigate the use and reproducibility of MRI transverse relaxation time (T2) mapping in healthy and inflamed gingivae. METHODS: 21 subjects were recruited into 2 groups: those without evidence of gingivitis ("healthy"; n = 11, age 24.0 ± 3.66 years) by visual assessment and those with moderate to severe gingivitis ("gingivitis"; n = 10, age 28.9 ± 6.03 years) exhibited across the second mandibular premolar and first mandibular molar buccal gingivae. Subjects were imaged by MRI twice in a single day. Three T2 weighted turbo spin-echo volumes with 0.25 × 0.25 × 0.8-mm3 resolution were acquired at echo times of 16, 32 and 48 ms for T2 decay fitting. Image analysis was fully blinded; the two imaging sessions were not identifiable as coming from the same subject. Each imaging session had independent regions of interest drawn on the first echo image and applied to the calculated T2 decay maps. RESULTS: The coefficient of variation was low and similar in healthy and gingivitis populations: 6.10 and 5.25% populations, respectively, with 5.65% populations across both groups. Bland-Altman analysis revealed no bias (mean -2.93%; 95% confidence intervals -22.20 to 16.34%) between sessions. The intersession agreement was good (r = 0.744, ρ = 0.568, intraclass correlation coefficient = 0.68). T2 mapping did not differentiate healthy from gingivitis groups. The mean T2 value in the healthy group (63.7 ms) was similar to that of the gingivitis group (65.23 ms) (p = 0.30). CONCLUSIONS: Mapping of the T2 decay in the gingivae was a repeatable process; however, T2 value alone did not differentiate those with clinical examination-determined gingivitis from those without signs of gingivitis.

Novel Air Stimulation MR-Device for Intraoral Quantitative Sensory Cold Testing.

The advent of neuroimaging in dental research provides exciting opportunities for relating excitation of trigeminal neurons to human somatosensory perceptions. Cold air sensitivity is one of the most frequent causes of dental discomfort or pain. Up to date, devices capable of delivering controlled cold air in an MR-environment are unavailable for quantitative sensory testing. This study therefore aimed at constructing and evaluating a novel MR-compatible, computer-controlled cold air stimulation apparatus (CASA) that produces graded air puffs. CASA consisted of a multi-injector air jet delivery system (AJS), a cold exchanger, a cooling agent, and a stimulus application construction. Its feasibility was tested by performing an fMRI stimulation experiment on a single subject experiencing dentine cold sensitivity. The novel device delivered repetitive, stable air stimuli ranging from room temperature (24.5°C ± 2°C) to -35°C, at flow rates between 5 and 17 liters per minute (l/min). These cold air puffs evoked perceptions similar to natural stimuli. Single-subject fMRI-analysis yielded brain activations typically associated with acute pain processing including thalamus, insular and cingulate cortices, somatosensory, cerebellar, and frontal brain regions. Thus, the novel CASA allowed for controlled, repetitive quantitative sensory testing by using air stimuli at graded temperatures (room temperature down to -35°C) while simultaneously recording brain responses. No MR-compatible stimulation device currently exists that is capable of providing non-contact natural-like stimuli at a wide temperature range to tissues in spatially restricted areas such as the mouth. The physical characteristics of this novel device thus holds promise for advancing the field of trigeminal and spinal somatosensory research, namely with respect to comparing therapeutic interventions for dentine hypersensitivity.

Three randomized clinical trials to assess the short-term efficacy of anhydrous 0.454% w/w stannous fluoride dentifrices for the relief of dentin hypersensitivity.

PURPOSE: To assess the short-term efficacy of dentifrices containing 0.454% weight/weight (w/w) stannous fluoride applied using a focused brushing methodology for the relief of dentin hypersensitivity (DH). METHODS: Three randomized, examiner blind, controlled, two treatment arm, parallel group studies were conducted utilizing a novel application method in which, prior to brushing the whole mouth, the stannous fluoride dentifrice was applied to two sensitive teeth by focused brushing. DH was assessed with an evaporative (air) stimulus (with the Schiff Sensitivity Scale and a Visual Analogue Scale [VAS, Studies 1 and 3 only]) and a tactile stimulus (using a Yeaple Probe). Clinical assessments were made at baseline, immediately after first use of study dentifrice and after 3 and 14 days of twice daily brushing. Study 1 compared a marketed 0.454% w/w stannous fluoride dentifrice indicated for short-term DH relief to a marketed standard fluoride dentifrice (negative control). Studies 2 and 3 compared a novel anhydrous 0.454% w/w stannous fluoride dentifrice to the same negative control. RESULTS: For Studies 1, 2 and 3, 118, 113 and 120 subjects respectively were randomized to treatment and included in the intent-to-treat populations. Study 1 showed significant DH improvements in all measures for the test dentifrice compared to the negative control at Day 14. Study 2 showed significant differences in favor of the test dentifrice for all measures at all time points (Immediate, Days 3 and 14). In Study 3, treatment with both test and control dentifrices resulted in significant improvements over baseline, but there were no significant between-treatment differences. While these studies provide evidence for relief of DH with 0.454% w/w stannous fluoride dentifrices after short-term use (14 days) using a novel focused brushing methodology, the evidence, especially at the earliest time points, is inconclusive and further testing is needed. Study dentifrices were well tolerated. ClinicalTrials.gov trial registration numbers: Study 1 NCT01494649; Study 2: NCT01592851; Study 3: NCT01724008; funded by GSK Consumer Healthcare.