A yellowness index for use in dentistry.

OBJECTIVES: To develop an equation that predicts the perceptual yellowness of teeth. METHODS: A large set of new psychophysical yellowness data were generated from an experiment where 500 participants each ranked a set of 58 shade guide samples. Two existing equations (WIO and b*) and one new equation (YIO) were evaluated by comparing their values for the 58 shade guide tabs with the psychophysical data. Coefficient of determination (r2), '% wrong decisions', and STRESS were used as measures of performance. The YIO equation was optimized using these data to maximize the r2 value. A validation set of psychophysical data was prepared in an experiment where 40 participants each ranked 5 sets of 9 samples that were viewed on an emissive display. The candidate equations were evaluated using these data and the r2, %WD, and STRESS metrics. RESULTS: All three metrics YIO, WIO and b* were strongly correlated with perceptual yellowness. YIO and WIO both showed stronger correlation than b*. CONCLUSIONS: A new yellowness equation YIO has been developed to correlate with tooth yellowness. It is suggested that tooth yellowness and whiteness are highly related concepts.

Tooth color and whitening - digital technologies.

OBJECTIVES: To review the key concepts of color in the dental domain with specific reference to the use of digital technology to measure color and color appearance. MATERIALS AND METHODS: The literature on color assessment in dentistry is considered and methods for assessing whiteness, yellowness and color appearance are collated and described. RESULTS AND CONCLUSION: A variety of methods for assessing color have been shown to exist and be viable including digital imaging. Equations to predict whiteness are identified; there is evidence that they are effective but further evaluation may be needed.

Investigation of the perceptual thresholds of tooth whiteness.

OBJECTIVE: To investigate the tooth whiteness perceptibility thresholds of the average observer to changes in the CIELAB values and an optimised whiteness Index for dentistry (WIO) based on psychophysical studies. METHODS: A psychophysical experiment based on visual assessments of digital images of teeth on a calibrated display with a group of observers (n=32) has been conducted to determine the perceptual thresholds in tooth whiteness. Digital simulations of a tooth that is identical in shape to the left incisor in the image of teeth were superimposed on to images. The colour of the simulated tooth was varied and observers were asked to respond whether there was a difference in whiteness between the left incisor and the simulated tooth. Thresholds for detection of differences in whiteness were independently determined in four conditions: ΔL*, Δa*, Δb* and a blue optical whitening direction. Raw data were fitted using a non-parametric approach and thresholds of CIELAB and WIO for each conditions were calculated. RESULTS: Estimates of the threshold of the four conditions of ΔL*, Δa*, Δb* and a blue covarine optical tooth whitening direction were 1.14, 3.24, 1.11 and 1.51 respectively, with the corresponding WIO thresholds of 2.77, 6.52, 3.09 and 1.99 respectively. CONCLUSIONS: The thresholds for tooth whiteness perception in CIELAB space and WIO space were determined. The findings demonstrate that for a whitening treatment with a blue covarine optical technology, a colour change of about 2 WIO units would be noticeable. CLINICAL SIGNIFICANCE: This study gives a better understanding of the tooth whiteness perception threshold, and will help clinicians identify perceivable differences in tooth colour during matching and whitening procedures.

Stain removal efficacy of two manual toothbrushes.

PURPOSE: To evaluate the dental stain removal efficacy of two commercially-available manual toothbrushes. METHODS: This was a randomized, examiner-blind, parallel-group, two treatment clinical trial of 2 weeks duration. Subjects qualifying for the study had a mean Modified Lobene Stain Index of ≥ 1.5 on at least two anterior teeth. Subjects were randomly allocated to one of two groups, receiving a test manual toothbrush (Oral-B 3D White Radiant) or a positive control (PC) manual brush to be used for 1 minute, twice daily for 2 weeks with a standard, anti-cavity fluoride dentifrice. Subjects were given written and verbal instructions, and the first use was supervised at the baseline visit. Stain was measured at baseline and after 2 weeks of product use. Stain measurements were conducted using the Modified Lobene Stain Index (MLSI) and the Interproximal Modified Lobene Stain Index (IMLSI). RESULTS: Use of the two manual brushes resulted in statistically significant reductions of surface stain relative to baseline after 2 weeks of use. The mean MLSI composite stain reductions versus baseline were 1.37 for White Radiant and 0.87 for PC (P < 0.001 for both). Using the IMLSI, the mean stain reductions for composite, gingival and interproximal regions were 1.68, 1.20 and 1.68 for White Radiant (P < 0.001) and 1.25, 0.97 and 1.43 for PC (P ≤ 0.002). ANCOVA yielded statistically significant between group differences, with greater composite stain removal observed for White Radiant using both indices (P ≤ 0.025).

Development of a customized whiteness index for dentistry based on CIELAB color space.

OBJECTIVES: To develop a customized CIELAB-based whiteness index for dentistry that accurately correlates to perception of tooth whiteness. METHODS: Four psychophysical experiments (PE1-4) were conducted by three panels of observers (OP1-3) under diffuse/0° observation/measuring conditions and under typical clinical viewing conditions. Nine whiteness indices (WI, Z%, WIC, WIO, W31, W64, W, WLAB, W*), two yellowness indices (YID1925, YIE313) and tint of white in the CIELAB color system (T) were compared with regard to their ability to measure the perceived whiteness of human teeth. Determination coefficient (R(2)) and '% wrong decision' (%WD) method were used as direct measures of the quality of the indices for whiteness perception in dentistry. RESULTS: CIELAB-based whiteness index (WID=0.511L* -2.324a* -1.100b*) was developed through optimization from the data obtained in PE1. The proposed WID performed better than all the CIELAB and CIE1931 XYZ-based indices under laboratory and clinical conditions (only WIO was comparable to WID in PE2 and PE4). CONCLUSION: The validation experiments under laboratory and typical clinical conditions revealed that the proposed index WID outperformed previous indices, being the only CIELAB-based index developed for evaluation of whiteness in dentistry.

Clinical Effectiveness Evaluation of a New Whitening Dentifrice.

OBJECTIVE: This randomized controlled clinical trial was conducted to determine the effectiveness and safety of a new whitening dentifrice. METHODS: One hundred eighty-two qualifying subjects were randomly assigned to either a whitening dentifrice group (Arm & Hammer Truly Radiant Toothpaste), a negative control dentifrice group (Colgate Cavity Protection Toothpaste), or a positive control dentifrice group (Crest 3-D White Radiant Mint Toothpaste) and were instructed to brush twice daily with their assigned dentifrice for six weeks. Extrinsic tooth stain was assessed using a Modified Lobene Stain Index (MLSI) and tooth shade was assessed using the VITA Classic Shade Guide at baseline and after five days and two, four, and six weeks of dentifrice use. Safety was monitored by clinical examinations and panelist assessment at each evaluation period. RESULTS: The Arm & Hammer Truly Radiant group showed a statistically significant improvement from baseline in mean composite MLSI and VITA shade at each examination period (p < 0.0001). Significant improvements on day 5 progressively increased with increasing duration of product use. By week 6, there was a 45.4% reduction in stain and a 2.08 improvement in tooth shade. The between-group comparison revealed that Truly Radiant toothpaste was significantly more effective than both the negative and positive control dentifrices for these parameters (p < 0.0001) at each exam time. CONCLUSION: This study showed that the new dentifrice formulation is safe and effective on stain removal and tooth whitening.

Extrinsic Stain Removal Effectiveness of a New Whitening Dentifrice.

OBJECTIVE: This study was conducted to evaluate the effectiveness of Arm & Hammer (A&H) Truly Radiant Rejuvenating toothpaste in removing extrinsic tooth stain compared to that of a conventional fluoride/silica-containing dentifrice. METHODS: This was a randomized, examiner-blind, parallel-design study with two groups of subjects who brushed unsupervised with their assigned dentifrice for two minutes, twice daily, for five days. Extrinsic stain was measured on the labial surfaces of the eight incisor teeth by the Modified Lobene Stain Index (MLSI) at baseline and following five days of product use. After balancing for baseline MLSI, beverage and tobacco use, fifty-four healthy adults with existing stain were randomly distributed into two comparable groups: Arm and Hammer Truly Radiant Rejuvenating toothpaste or Colgate Cavity Protection toothpaste (negative control). Within-treatment comparisons between baseline and day five were made using matched-pair t-tests, and between-treatment comparisons of MSLI scores were performed using ANCOVA, with baseline scores as covariates. RESULTS: Twenty-eight subjects in the Truly Radiant Rejuvenating toothpaste group and twenty-six subjects in the negative control group completed the study. The groups had comparable mean scores at baseline (p > 0.05). The Truly Radiant Rejuvenating toothpaste produced a statistically significant 23.1% total (composite) stain reduction from baseline after five days of product use (p < 0.0001) while the negative control was essentially unchanged (p > 0.05). Between-treatment analysis showed statistically significantly (p < 0.0001) greater stain removal for Truly Radiant Rejuvenating toothpaste compared to the Colgate control following five days of product use. There were no adverse events reported during the study. CONCLUSION: The A&H Truly Radiant Rejuvenating toothpaste is safe and effective in reducing extrinsic stain compared to a regular toothpaste control.

Clinical Study to Assess the Stain Removal Effectiveness of a Tooth Whitening Regimen with Added Whitening Booster.

OBJECTIVE: This randomized, controlled clinical trial was conducted to assess the extrinsic stain reduction achieved by brushing with a whitening dentifrice and powered toothbrush, and to determine whether the addition of a whitening booster paste to this regimen would enhance its stain reducing effectiveness. METHODS: Sixty qualifying subjects were randomly assigned either to Regimen One, a whitening dentifrice (Arm & Hammer Truly Radiant [TR] toothpaste] and powered toothbrush (Arm & Hammer Truly Radiant [TR] Extra Whitening Spinbrush); Regimen Two, the dentifrice and powered toothbrush with the addition of a whitening booster; or Regimen Three, a negative control (Colgate Cavity Protection toothpaste and an ADA standard manual brush). They were instructed in the use of their assigned products and then brushed unsupervised at home for two minutes, twice daily, for 14 days. Extrinsic tooth stain was assessed at baseline and after two, five, and 14 days using a Modified Lobene Stain Index (MLSI) with Lobene inclusion criteria of ≥ 1.5. RESULTS: All three treatment groups had statistically significant (p < 0.0001) mean total MLSI reductions from baseline at each time point, in a time-dependent manner. Day 14 reductions were 22.2% for Colgate Cavity Protection, 29.1% for Regimen One, and 34.4% for Regimen Two. Reductions for Regimen One and Regimen Two were significantly greater compared to Regimen Three, the negative control, at each time period (p < 0.01), and those for Regimen Two were significantly greater compared to Regimen One on days 2 and 14 (p < 0.05) and directionally more effective on day 5 (p = 0.0673). CONCLUSION: The combination of Truly Radiant toothpaste and Truly Radiant Spinbrush provides safe and effective stain removal that can be further enhanced by the addition of the whitening booster.

Stain Removal Assessment of Two Manual Toothbrushes with an Interproximal Tooth Stain Index.

OBJECTIVE: To assess a newly developed index to measure interproximal stain and evaluate the stain removal efficacy of two commercially available manual toothbrushes. METHODS: This was a randomized, examiner-blind, parallel-group, two-treatment clinical trial of two weeks' duration. Subjects qualified for the study if they had an average Modified Lobene Stain Index of ≥ 1.5 from two anterior teeth. At baseline, subjects brushed in front of a mirror for one minute under supervision. All subjects were provided with a standard 0.243% sodium fluoride dentifrice and were randomly assigned either an Oral-B Pulsar manual brush (OBP) or a Colgate Whitening manual brush (CW) to use for two weeks. Stain was reassessed after two weeks of product use. Stain measurements were conducted using the Modified Lobene Stain Index and the new Interproximal Modified Lobene Stain Index, which allows for assessment of stain in hard-to-reach areas using the same area and intensity scales as the Modified Lobene Stain Index. RESULTS: Use of the two manual brushes resulted in statistically significant reductions in surface stain relative to baseline after two weeks of use. Median stain reductions were 78% and 60% for the OBP and CW, respectively, as measured by the Modified Lobene Stain Index. The mean changes in the composite scores from baseline to week two were 1.85 and 1.57 for the two treatment groups, respectively. Statistically significant reductions from baseline were also found for the intensity and extent of stain measures (p < 0.001). Similar trends were found using the new Interproximal Modified Lobene Index. Composite median stain removal percentages versus baseline were 88% and 73% for the OBP and CW groups, respectively (p < 0.001). For the interproximal sites, a median stain removal of 92% was observed with the OBP brush and 83% reduction with the CW brush. For the gingival sites, the median stain removal percentages were 83% and 50%, respectively For the body region, a median stain removal of 100% was found for both treatment groups. No statistically significant differences were found between the two groups for the mean composite scores for either index. CONCLUSION: Both manual brushes showed effective stain removal, including interproximal hard-to-reach sites. The Interproximal Modified Lobene Stain Index gave clinically relevant results consistent with the traditional Modified Lobene Stain Index, while allowing assessment of interproximal regions.

A Randomized Clinical Study Investigating the Stain-Removal Potential of Two Experimental Dentifrices.

OBJECTIVE: To evaluate the ability of two experimental desensitizing dentifrices, both containing a chemical cleaning agent, one with ultra-low abrasivity and one with low abrasivity, a standard fluoride dentifrice, and a daily-use whitening dentifrice to remove extrinsic tooth stain. METHODS: This was a single-center, examiner-blind, randomized, controlled, four-treatment, parallel-group study in healthy adults. Extrinsic stain was evaluated using the Macpherson modification of the Lobene Stain Index (MLSI). At baseline, eligible subjects with a total MLSI (area x intensity [A x I]) score of 15 for the facial surfaces of the 12 anterior teeth were stratified (based on total MLSI [A x I] score [< 45 = low; ≥ 45 = high] and smoking status) and randomized to treatment with one of four dentifrices: an experimental ultra-low abrasivity desensitizing dentifrice (relative dentin abrasion [RDA] -12); an experimental low abrasivity desensitizing dentifrice (RDA -40); a standard fluoride dentifrice with moderate abrasivity (RDA -80); and a whitening dentifrice with higher abrasivity (RDA -142). Both desensitizing dentifrices contained 5% potassium nitrate and 5% sodium tripolyphosphate (a chemical cleaning agent). Treatment effects were evaluated after four and eight weeks of twice-daily brushing. RESULTS: In total, 142 subjects were randomized and 133 subjects completed the study. All study dentifrices demonstrated statistically significant reductions in extrinsic tooth stain from baseline after four and eight weeks of twice-daily use (p < 0.01). There were no statistically significant between-treatment differences for the primary variable (mean MLSI [A x I] score across all assessed sites) at four or eight weeks, and no notable trends were observed. CONCLUSION: All study dentifrices reduced extrinsic tooth stain. The experimental ultra-low and low abrasivity desensitizing dentifrices containing 5% sodium tripolyphosphate performed similarly to both a moderate abrasivity standard fluoride dentifrice and a higher abrasivity whitening dentifrice.

Introducing dental hygienists in general practice to research - an in-practice evaluation programme in the United Kingdom.

AIM: To introduce dental hygienists (DHs) in the UK to the principles of research through a practice-based product evaluation programme. METHODS: The programme consisted of an initial training and orientation day with presentations on evidence-based practice, research methods and the structure of research papers. The programme and its aims were explained in detail, and participants were briefed on the methods to be used. Participants then recruited seven to ten patients from their practices (offices), carried out a baseline assessment of: plaque, gingival health, calculus and staining at anterior teeth, and gave the patients a questionnaire asking about their teeth and then provided a 3-month supply of a test toothpaste. About 10 weeks later, a follow-up assessment of the same variables was performed and the questionnaire was repeated. A second training day followed during which the DHs provided feedback of their experiences and received training in literature searching and critical appraisal of literature including interpretation of results. RESULTS: Sixty-five DHs attended the first training day; 31 were able to recruit sufficient patients and attend the second training day. The DHs recruited 168 patients who received baseline and follow-up assessments. All the variables improved overall. Feedback from the DHs was very positive, and patients expressed delight with the care they had received. CONCLUSIONS: Qualitative feedback for participating DHs suggests the programme met its aim and could be used in the future as a mechanism for helping DHs who want to increase their understanding of research methodology.

Evaluation of the antigingivitis effect of a chlorhexidine mouthwash with or without an antidiscoloration system compared to placebo during experimental gingivitis.

AIM: The aim of the present study was to evaluate the effectiveness of chlorhexidine (CHX) with an antidiscoloration system (ADS) on stain, plaque accumulation, and gingivitis. METHODS: A randomized, controlled clinical trial was conducted in 26 students. After a preparatory period, the students were randomly assigned to either group P (placebo), group T1 (0.12% CHX without an ADS), or group T2 (0.12% CHX with an ADS). During the 3-week experimental period, all mechanical oral hygiene was abolished. Rinsing with 10 mL mouthwash or placebo was performed twice daily under supervision. The parameters assessed on days 0, 7, 14, and 21 included the Discoloration Index (DI), Plaque Index (PII), and Gingival Index (GI). RESULTS: There were no significant mean differences in the DI, PII, or GI between groups T2 and P. Significant mean differences existed in the DI between groups T2 and T1 on days 14 and 21. Significant mean differences existed in the PI between groups T2 and T1 on days 7, 14, and 21. Likewise, significant mean differences existed in the GI between groups T2 and T1 on days 14 and 21. CONCLUSIONS: CHX with an ADS did not prevent plaque or gingivitis development. In fact, the CHX mouthwash with an ADS showed no superior effect over placebo on oral hygiene or the prevention of gingivitis.

The efficacy of chlorhexidine dentifrice or gel on plaque, clinical parameters of gingival inflammation and tooth discoloration: a systematic review.

AIM: Based on the existing scientific literature, the effect of chlorhexidine (CHX) dentifrice/gel as compared to a regular or placebo dentifrice/gel is established in healthy adults on the primary outcome parameters of plaque and gingivitis scores. As secondary parameter, tooth surface discoloration was evaluated as a side effect. MATERIALS AND METHODS: MEDLINE, EMBASE and Cochrane Central Register of Controlled Trials were searched up to July 2013 to identify eligible studies. Included were (randomized) controlled clinical trials, regarding self-performed brushing by adults without periodontitis with a minimum duration of 4 weeks. RESULTS: Independent screening of 389 unique titles and abstracts resulted in 16 comparisons. Of these, nine evaluated CHX dentifrice (0.4-1.0%) and 7 CHX gel (0.2-2.0%). It was not possible to perform a meta-analysis; therefore, a descriptive analysis was carried out. Regarding plaque score reduction, the majority of the experiments using a CHX dentifrice provided a significant positive effect. All studies assessing gingival bleeding as parameter for gingivitis observed a significant reduction in favour of CHX dentifrice over placebo dentifrice. Tooth surface discoloration was more pronounced with CHX dentifrice. The combined data concerning parameters of interest for CHX gel compared with a placebo did not show a trend towards a beneficial effect on plaque and bleeding scores. CONCLUSIONS: Within the limitations of this analysis, it may be concluded that toothbrushing with a CHX gel does not provide conclusive evidence. Brushing with a CHX dentifrice can be effective with regard to the control of plaque and gingivitis. Tooth surface discoloration was observed as side effect, which potentially can have a negative impact on patients' compliance.

In vitro assessment of tooth color alteration by two different types of endodontic irrigants.

AIM: The purpose of this study was to assess in vitro the tooth color alterations associated with two commonly used endodontic irrigants, the chlorhexidine gluconate (CHX) and the sodium hypochlorite (NaOCl) up to 15 days post-treatment. Additionally, the possible influence of endodontic access preparation on tooth color was investigated. MATERIALS AND METHODS: Thirty intact human anterior teeth were used. Black adhesive tape with a 4 mm diameter window was used to standardize the enamel surface intended for color analysis. After the access cavity, preparation and the initial root canal negotiation with stainless steel hand files, the root canal shaping was completed with rotary nickel-titanium files. The teeth were divided into three groups (n = 10). Conventional syringe irrigation was performed with one irrigant for each group. The enamel surfaces were colorimetrically evaluated before access cavity, after cavity preparation and at 1, 3, 7 and 15 days post-treatment. The CIE color parameters (L*, a*, b*) were recorded and averaged for each material and the corresponding color differences (ΔE) were calculated and statistically analyzed. RESULTS: The most significant factor in tooth color alteration, during the endodontic treatment, was the access preparation. CHX and NaOCl caused tooth color changes comparable with the saline. CHX and NaOCl did not increase the tooth color changes relative to the values induced by the access preparation. CONCLUSION: The two endodontic irrigants were not able to induce tooth color alteration to a greater extent than the access preparation. CLINICAL SIGNIFICANCE: Chlorhexidine and NaOCl cannot be considered as discoloring endodontic materials. The most contributing factor in tooth color alteration during endodontic treatment in the anterior teeth is access preparation.

Caries diagnosis: agreement between WHO and ICDAS II criteria in epidemiological surveys.

OBJECTIVE: The aim of this study was to ascertain the equivalence between WHO caries diagnosis criteria and the ICDAS II caries classification scale for comparisons in epidemiological studies. MATERIALS AND METHODS: Two intraoral examinations, one using the ICDAS II caries codes and the other the WHO caries assessment method, were performed in a random sample of 101 children (29 aged 5-6 years, 32 aged 12 and 40 aged 15). Both examinations were performed not more than one month apart by two calibrated examiners (one for ICDAS II criteria, Kappa=0.86, and the other for WHO criteria, Kappa=0.91). The DMFT/dft, DMFS/dfs and caries prevalence (DMFT or dfs>0) indices were obtained in accordance with WHO assessment criteria and by applying 5 cut-off points on the ICDAS II scale. The differences between means were analysed with the Wilcoxon test and those between proportions with the McNemar test. Agreement was determined by the intraclass correlation index and the Kappa statistic. RESULTS: The least differences between the WHO and ICDAS 11 criteria were found at cut-off point 3 (ICDAS 11 codes 3 to 6). The greatest agreement was found at the same cut-off point. CONCLUSION: While the equivalence between both methods used in epidemiological studies does not appear to be clear, possible errors could be reduced by locating this equivalence at cut-off point 3 and not at cut-off point 4.

Direct measurement of stain retention in third molars.

AIM: To directly determine the mass of dye retained in teeth following exposure to aqueous solutions of Rhodamine B and to correlate tooth color modifications. MATERIALS AND METHODS: Extracted third molars (25) were selected and sectioned at the cementoenamel junction for coronal staining. Pulp tissue was removed and teeth sonicated to remove debris. Teeth were kept in deionized water for 12 hours and subsequently weighed. They were then stained for 4 hours in 5 ml of Rhodamine B dye at two different concentrations. The samples were then subjected to two 8 hours rinses in deionized water. The tooth shade was recorded with a commercially available intraoral spectrophotometer (Vita Easyshade Compact, Vita Zahnfabrik, Bad Säckingen, Germany) at baseline (T1), after dye immersion (T2), and after water rinsing (T3). A standard absorption curve was then used to calculate the dye mass in the rinse solutions as well as the post- treatment stain solutions. All solution optical absorption curves were recorded using a laboratory research spectrophotometer (Cary 300, Agilent, USA). The mass of dye in each solution was then calculated from the standard curve relating optical absorption to aqueous dye concentration. RESULTS: An average change in the CIE (a) values of 8.0 ± 0.3 were observed for concentrations of Rhodamine B similar to the optical appearance of wine or other darkly colored juices while an increase of 10× in concentration gave values too high to measure using a standard intraoral spectrophotometer. By measuring the optical absorbance of the staining solutions before and after the staining process, we were able to measure dye retention of 54 ± 26 micrograms per gram of tooth. CONCLUSION: While no significant correlation could be found between the amount of stain retention in the dentition and the tooth shade due to the high uncertainties in the spectroscopic measurements, we were able to show that this method should admit such comparisons for future research. CLINICAL SIGNIFICANCE: The development of a reliable chromophore infiltration model may provide standardized and reproducible results in evaluating tooth whitening efficacy.

Salivary parameters and caries indices in children with black tooth stains.

OBJECTIVE: Black tooth stain in children has been associated commonly with a low caries experience. The present study aimed to to compare salivary factors and caries indices in children with and without black tooth stain and to investigate the relationship between caries and caries associated salivary factors in these children. STUDY DESIGN: Salivary flow rate, pH, buffering capacity, total calcium and phosphorus were determined. Calcium and phosphorus levels were assayed by Inductive Coupled Plasma with Atomic Emission Spectrometry. DMFT and dft indices were evaluated according to WHO criteria. RESULTS: Significantly higher levels of salivary buffering capacity and calcium, and lower flow rate were found in children with black tooth stain compared with those of without black tooth stain (p < 0.01, p = 0.044 and p = 0.037, respectively). The differences in phosphorus and pH were not significant between the groups. The dft index was found to be significantly lower in children with black tooth stain than children without black tooth stain (p = 0.030). However, DMFT did not change between the groups. There is no relationship between salivary parameters and caries indices in children with black tooth stain. CONCLUSION: It is suggested that low caries tendency seen in children with black tooth stain may be associated with high salivary calcium and buffering capacity.

Randomized controlled trial to evaluate tooth stain reduction with nicotine replacement gum during a smoking cessation program.

BACKGROUND: In addition to its general and periodontal health effects smoking causes tooth staining. Smoking cessation support interventions with an added stain removal or tooth whitening effect may increase motivation to quit smoking. Oral health professionals are well placed to provide smoking cessation advice and support to patients. The objective of the present study was to evaluate the effect of Nicorette(®) Freshmint Gum used in a smoking cessation programme administered in a dental setting, on extrinsic stain and tooth shade among smokers. METHODS: An evaluator-blinded, randomized, 12-week parallel-group controlled trial was conducted among 200 daily smokers motivated to quit smoking. Participants were randomised to use either the Nicorette(®) Freshmint Gum or Nicorette(®) Microtab (tablet). Tooth staining and shade were rated using the modified Lobene Stain Index and the Vita(®) Shade Guide at baseline, weeks 2, 6 and 12. To maintain consistency with other whitening studies, the primary end-point was the mean change in stain index between baseline and week 6. Secondary variables included changes in stain measurements and tooth shade at the other time points the number of gums or tablets used per day and throughout the trial period; and the number of cigarettes smoked per day. Treatments were compared using analysis of covariance (ANCOVA), using treatment and nicotine dependence as factors and the corresponding baseline measurement as a covariate. Each comparison (modified intention-to-treat) was tested at the 0.05 level, two-sided. Within-treatment changes from baseline were compared using a paired t-test. RESULTS: At week 6, the gum-group experienced a reduction in mean stain scores whilst the tablet-group experienced an increase with mean changes of -0.14 and +0.12 respectively, (p = 0.005, ANCOVA). The change in mean tooth shade scores was statistically significantly greater in the gum-group than in the tablet group at 2 (p = 0.015), 6 (p = 0.011) and 12 weeks (p = 0.003) with greater lightening in the gum-group at each examination period. CONCLUSION: These results support the efficacy of the tested nicotine replacement gum in stain reduction and shade lightening. These findings may help dentists to motivate those wishing to quit smoking using a nicotine replacement gum. TRIAL REGISTRATION: NCT01440985.

Retrospective long-term evaluation of autotransplantation of premolars to the central incisor region.

AIM: This retrospective case-series study aimed to examine the long-term outcomes of autogenously transplanted premolars. METHODOLOGY: Twelve patients in whom donor premolars were used to replace maxillary central incisors lost by trauma were clinically and radiologically monitored. Standardized clinical and radiographic records were systematically obtained during the follow-up period of 14 years, to determine the influence of specific clinical criteria on the overall success rate of transplantation. RESULTS: The success rate of premolar autotransplantation in the maxillary central incisor area was 80% after 14 years follow-up. The highest success rate occurred in those teeth transplanted with two-thirds of full root development. Complete pulp obliteration was positively related to autotransplant viability, followed by root formation in the bony crypt. CONCLUSIONS: Autotransplantation of donor teeth, at the stage of ½ to ¾ of their expected root length, can provide a successful treatment solution for over 14 years.

Transient discoloration of the coronal fragment in intra-alveolar root fractures.

BACKGROUND: Root fractures are a relatively rare type of injury with frequencies of 0.5-7% of traumatized permanent teeth. It is well known that teeth with intra-alveolar root fractures have a good prognosis. The pulp remains vital in about 80% of these teeth. If pulp necrosis develops, this normally only occurs in the coronal fragment. Although several studies on intra-alveolar root fractures have been published during the last decades, none have mentioned that transient discoloration can occur. The aim of our study was to study the frequency and prognosis for intra-alveolar root fractures with discoloration. MATERIAL AND METHODS: The material consisted of 42 permanent incisors from 21 boys and 18 girls aged 7-19 years (mean = 12.7, median 12.0). In two girls and one boy, two incisors exhibited concurrent intra-alveolar root fractured. The follow-up period ranged from 1 to 9 years. The colour changes were determined at each control by transillumination of the clinical crown from the facial and palatal surfaces. Electrometric sensibility was evaluated and compared to the values of adjacent teeth using an electric pulp tester. At the final clinical and radiographic control, the type of healing was registered. RESULTS: Discoloration was found in nine teeth. The root development was completed in all these teeth. The discoloration disappeared within 4 weeks to 6 months in eight teeth. The sensibility, which was lost at the injury, followed the changes in discoloration, and all teeth had regained normal sensibility when the discoloration had disappeared. Only one tooth, which showed a greyish hue, developed pulp necrosis. CONCLUSION: Transient discoloration in intra-alveolar fractures is relatively common and is indicative of a good prognosis for healing.