Avaliação clínica prospectiva randomizada do monitoramento digital de pacientes submetidos ao clareamento caseiro: efeito do tempo de uso do produto clareador nos graus de colaboração e satisfação do paciente, na efetividade e ocorrência de sensibilidade / Clinical prospective randomized evaluation of the digital monitoring of patients submitted to home bleaching: effect of the wear time of the bleaching product on the levels of collaboration and patient satisfaction, on the effectiveness and occurrence of sensitivity

Este estudo prospectivo, randomizado e paralelo analisou a alteração de cor, sensibilidade dental, grau de cooperação e satisfação de voluntários quando submetidos ao clareamento dental com peróxido de carbamida a 10%, empregado durante 21 dias por 2, 4 e 8 horas/dia. O tempo preciso do uso diário das moldeiras/produto clareador foi mensurado por meio de um microssensor TheraMon (Sales Agency Gschladt, Hargelsberhg, Áustria). Sessenta e seis voluntários, de ambos os gêneros, com idades entre 18 e 22 anos foram selecionados e distribuídos aleatoriamente em três grupos de estudo (n = 22), os quais receberam as informações sobre a presença do microssensor em suas moldeiras. O fator estudado foi o tempo de uso das moldeiras em três níveis: 2 (GI), 4 (GII) e 8 (GIII) hrs/dia. Para a análise clínica, as variáveis de resposta foram: grau de cooperação diária dos voluntários de acordo com o tempo de uso diário das moldeiras; grau de satisfação dos voluntários com o clareamento dental; eficácia do clareamento dental nos incisivos e caninos superiores e inferiores pelo método visual (Vita Classical) e digital (Vita Easyshade), assim como o grau de sensibilidade dental que foi avaliado com método analógico-visual. Os voluntários foram avaliados no período inicial (baseline), aos 7, 14 e 21 dias após o início do tratamento clareador e 14 dias após apenas para as observações da cor, sensibilidade e grau de satisfação. Os dados foram analisados com aplicação do teste ANOVA e pelo post teste de Tukey. Para o grau de cooperação diária dos voluntários, foram utilizadas observações dos tempos de uso das moldeiras (escores/dias) para cada arco e correspondentes a cada semana de tratamento. A análise digital apontou um mesmo nível de alteração de cor em todos os tempos de análise e de uso das moldeiras/produto clareador; exceção para o tempo de análise 7 dias do arco superior, que evidenciou uma maior alteração de cor para os maiores tempos de uso das moldeiras/produto clareador. A análise visual evidenciou que os maiores tempos de uso das moldeiras/produto clareador apresentou uma maior alteração de cor, após o tratamento clareador. A sensibilidade dental foi observada durante o tratamento clareador, mas postou-se praticamente ausente 14 dias após o clareamento. A maioria dos voluntários não seguiram as prescrições sugeridas do tempo de uso diário das moldeiras/produto clareador, sendo que os voluntários que as usaram pelo menor tempo apresentaram um maior grau de cooperação. A utilização das moldeiras/produto clareador por mais tempo foi capaz de proporcionar maior efetividade na alteração de cor e no grau de satisfação dos voluntários. Quanto mais prolongado o tempo de uso diário das moldeiras/produto clareador, maiores as chances de os voluntários não seguirem o protocolo recomendado(AU)

This prospective, randomized, parallel study analyzed the color change, tooth sensitivity, degrees of cooperation, and satisfaction of volunteers when submitted to at home dental bleaching with 10% carbamide peroxide (Opalescence - Ultradent Products, Inc. South Jordan, USA) for 21 consecutive days for 2, 4 and 8 hours/day. The wear time of acetate trays/dental bleaching was measured through a TheraMon microsensor (TheraMon® microelectronic system; Sales AgencyGschladt, Hargelsberhg, Austria). Sixty six volunteers, both sexes, with ages ranging from 18 to 22 years were selected and randonly distributed into 3 study groups (n=22). The volunters received information about presence of the microsensor in their trays. The fator studied was the wear time of the trays in three levels: during 2 (GI), 4 (GII) and 8 (GIII) hours/day. For the clinical analysis the response variables were: the degree of daily cooperation of the volunteers as the wear time/daily of the trays, microelectrically collected by micro sensor TheraMon®; the degree of satisfaction of volunteers with dental bleaching; the effectiveness of dental bleaching in the upper and lower incisors and canines teeth, by the visual method (Vita Classical) and digital (Vita Easyshade) and dental sensitivity was evaluated by the volunteers with a scale visual analog method on a scale of 0 to 10. The volunteers were evaluated at baseline period, at one, two and three weeks after the beginning of the bleaching treatment, and again two weeks after the bleaching treatment only for the observations of the color, sensitivity and degree of satisfaction. The data were analyzed using the ANOVA test and the Tukey post test. The digital analysis showed the same level of color change in all times of analysis and wear time of the trays; exception for the analysis time 7 days of the upper arch, which evidenced a greater color change for the longer time of wear time of the trays. The visual analysis evidenced that the greater wear time of the trays presented a greater color change, after the bleaching treatment. Dental sensitivity was observed throughout the bleaching treatment, but it was practically absent 14 days after treatment. Most of the volunteers did not follow the suggested prescriptions of the wear time daily of the trays, with those who used them for the shortest time presenting the highest degree of cooperation. The wear time of the trays/bleaching product for 8 hours/day, provided greater effectiveness of the color change in the visual and digital analysis, as well as greater degree of satisfaction of the volunteers. A discreet sensitivity was observed throughout the bleaching treatment, but it was practically absent 14 days after bleaching. It was observed that the volunteers did not follow correctly the prescriptions of the wear times of the trays/bleaching product, evidencing less the degree of collaboration of the volunteers for the greater wear times of the trays(AU)

The effects of at-home whitening on patients' oral health, psychology, and aesthetic perception.

BACKGROUND: The aesthetic self-perception and psychosocial impact of whitening is poorly explored in the literature; it is even less clear whether the effect of whitening may influence the psychology or social relations of patients. Therefore, the aim of this trial is to evaluate the impact of an at-home whitening procedure on patients' quality of life. Also, this study's secondary objective is the adaptation and validation of the Spanish version of the OES questionnaire (OES-SP). METHODS: Fifty eight patients underwent whitening with 10% carbamide peroxide (CP) gel for 1 h daily for 3 weeks. For these participants, the OHIP-Esthetics, PIDAQ, and OES surveys were applied before, one week after, and one month after the whitening procedure. Oral health-related quality of life was measured using the OHIP-Esthetics survey and the psychosocial impact using the PIDAQ survey. The orofacial aesthetics was measured by OES and validated for the Spanish Chilean context. The treatment efficacy (ΔE and ΔSGU) and data from the OHIP-Esthetics PIDAQ and OES surveys were compared using the Wilcoxon Signed-Rank test. RESULTS: The whitening procedure was effective (ΔE = 5.9 ± 1.8). The OHIP-Esthetics results were significant when comparing the initial baseline survey prior to the treatment and one week after whitening (p < 0.001) and when comparing the baseline and one-month results (p < 0.001). The overall score on the PIDAQ, after one week post-whitening, was separated into factors and all factors were statistically significant (p < 0.03); the factors for the one-month results were also all statistically significant (p < 0.001), except the social impact factor. The OES questionnaire had statistically significantly increased scores both one week and one month post-treatment (p < 0.0001). The reliability, validity, and responsiveness of the OES-SP were satisfactory. CONCLUSION: The at-home whitening procedure with carbamide peroxide 10% had a positive effect on patients' oral health-related quality of life, psychology, and aesthetic perception after one month post-whitening. The Chilean Spanish version of the OES showed satisfactory psychometric characteristics to evaluate dental whitening. TRIAL REGISTRATION: NCT02605239 . Date that the study was retrospectively registered: 11-11-2015.

Desire for tooth bleaching and treatment performed in Brazilian adults: findings from a birth cohort.

Population-based studies estimating the prevalence of tooth bleaching desire or the percentage of individuals who had performed this treatment are rare. Thus, the aim of this study was to evaluate the desire to perform tooth bleaching and the prevalence of adult individuals who had performed the treatment and investigate the association of these outcomes. A subsample (n = 536) of the 1982 Pelotas birth cohort in southern Brazil was investigated at the ages 15, 24 and 31 by clinical examinations and interviews. The prevalence of bleaching at 31 years was 15.6% [95%CI 12.6-18.9] while 85.9% [95%CI 82.7-88.7] reported they desired the treatment. Multivariate Poisson regression analysis showed that individuals who have visited the dentist within the last year showed a treatment prevalence ratio (PR) 2.31 times [95%CI 1.40-3.83] higher compared with those who had the last dental visit more than a year before the interview. Similarly, individuals with smoking habits presented an elevated PR of 1.60 [95%CI 1.00-2.55], and the low-income trajectory group showed the largest PR of desire for tooth bleaching (1.17 [95%CI 1.07-1.28]). Moreover, individuals from the high-risk caries trajectory group presented a higher prevalence of desire for tooth bleaching than individuals from low caries trajectory group. Individuals who have declared being "dissatisfied" with their dental color presented a prevalence of desire for tooth bleaching 16% greater than "satisfied" ones. Thus, the present findings confirm that tooth bleaching has become a frequently desired dental treatment to improve dental aesthetics in the population and a considerable rate of adults has performed the treatment.

Desire for tooth bleaching and treatment performed in Brazilian adults: findings from a birth cohort

Abstract: Population-based studies estimating the prevalence of tooth bleaching desire or the percentage of individuals who had performed this treatment are rare. Thus, the aim of this study was to evaluate the desire to perform tooth bleaching and the prevalence of adult individuals who had performed the treatment and investigate the association of these outcomes. A subsample (n = 536) of the 1982 Pelotas birth cohort in southern Brazil was investigated at the ages 15, 24 and 31 by clinical examinations and interviews. The prevalence of bleaching at 31 years was 15.6% [95%CI 12.6-18.9] while 85.9% [95%CI 82.7-88.7] reported they desired the treatment. Multivariate Poisson regression analysis showed that individuals who have visited the dentist within the last year showed a treatment prevalence ratio (PR) 2.31 times [95%CI 1.40-3.83] higher compared with those who had the last dental visit more than a year before the interview. Similarly, individuals with smoking habits presented an elevated PR of 1.60 [95%CI 1.00-2.55], and the low-income trajectory group showed the largest PR of desire for tooth bleaching (1.17 [95%CI 1.07-1.28]). Moreover, individuals from the high-risk caries trajectory group presented a higher prevalence of desire for tooth bleaching than individuals from low caries trajectory group. Individuals who have declared being "dissatisfied" with their dental color presented a prevalence of desire for tooth bleaching 16% greater than "satisfied" ones. Thus, the present findings confirm that tooth bleaching has become a frequently desired dental treatment to improve dental aesthetics in the population and a considerable rate of adults has performed the treatment.

One-year follow-up of at-home bleaching in smokers before and after dental prophylaxis.

OBJECTIVE: This clinical study evaluated the color longevity after one-year of at-home bleaching with 10% carbamide peroxide (CP) in smokers and nonsmokers. METHODS: Sixty patients, 30 smokers and 30 non-smokers were subjected to bleaching with 10% CP during three hours daily for three weeks. The color was measured at baseline and one week, one month and one year after the completion of dental bleaching using the spectrophotometer Vita Easyshade (ΔE*), shade guide Vita classical organized by value and Vita Bleachedguide 3D-MASTER (ΔSGU). In the one-year recall, the color was assessed before and after dental prophylaxis with Robinson brush and prophylaxis paste. Data from color evaluation were analyzed by two-way repeated measures ANOVA and Tukey's test for the contrast of means (α=0.05). RESULTS: Twenty-seven smokers and 28 non-smokers attended the one-year recall. For both study groups, only the main factor assessment time was statistically significant for ΔSGU (Vita classical) and ΔE* (p<0.001). Effective whitening was observed for both groups at baseline, which was stable at one-month and one year after dental prophylaxis. A slight darkening was observed after one year when the color was measured without prophylaxis. For the Vita Bleachedguide 3D-MASTER, color rebound was observed irrespectively of dental prophylaxis. CONCLUSION: The bleaching with 10% CP remained stable in both groups as long as extrinsic stains from diet and cigarette smoke were removed by professional dental prophylaxis. CLINICAL TRIALS REGISTRY: NCT02017873. CLINICAL RELEVANCE: The results of this study indicate that the bleaching is effective in smokers even after one-year, but dental prophylaxis may be necessary to remove extrinsic stains caused by diet and smoking.

Teeth whitening versus the influence of extrinsic factors on teeth stains.

The improvement of teeth colour is the effect of using whitening toothpastes, professional removal of dental deposits, pulpless teeth and vital teeth whitening. The aim of the study was evaluation of various methods of teeth whitening in relation to sex and age of the investigated as well as the extrinsic factors causing teeth stains such as cigarette smoking, consumption of coffee and tea. Questionnaire survey was conducted in the group of 204 patients, reporting for a dental treatment at the Chair and Department of Conservative Dentistry with Endodontics of the Medical University of Lublin as well as private dental practice in Lublin. Questionnaire survey was elaborated for the needs of the planned investigation and included questions concerning, among others, socio-demographic data of the investigated, methods of teeth whitening, cigarette smoking, consumption of coffee and tea. Statistic analysis was performed with the use of descriptive statistics, Chi2 test, Mann-Whitney test. The values of p < 0.05 were considered statistically essential. Women used whitening toothpastes more frequently in comparison with men (χ2 = 7.96, p < 0.01). People who declared drinking at least one coffee cup used whitening toothpastes more frequently in comparison with the people drinking coffee occasionally and those who didn't drink it (χ2 = 9.99, p < χ0.05).

Tooth whitening in the orthodontic practice: a survey of orthodontists.

INTRODUCTION: The demand for tooth whitening has grown almost exponentially in the last 20 years, but there are no published reports regarding how bleaching is used in contemporary orthodontic practices in the United States. METHODS: A weighted sample of American Association of Orthodontists members (3601) was surveyed via electronic and paper questionnaires to quantitatively, by logistic regression, and qualitatively assess orthodontists' current practices regarding tooth-whitening procedures. RESULTS: Of the surveys, 1222 were completed, and 1182 surveys were eligible for analysis. Nationwide, 88.8% of orthodontists had patients who requested tooth whitening, and 76.2% of orthodontists had recently recommended whitening procedures for some patients, typically less than 25% of their total patient population. Approximately a third (32.8%) of orthodontists provided whitening, and nearly two thirds (65.8%) referred whitening procedures to other dental professionals. The geographic region of the country had a statistically significant effect on the proportion of orthodontists who received whitening requests (P = 0.004), recommended whitening procedures (P <0.0006), and provided whitening services in their specialty practices (P <0.0001). CONCLUSIONS: Almost all orthodontists encounter patients who request whitening procedures, and most recommend whitening procedures for a small percentage of their patients. The proportion of orthodontists who refer such procedures to other providers is nearly double the proportion that provides them.

The prevalence of dentin hypersensitivity in general dental practices in the northwest United States.

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.

Contemporary dental practice in the UK in 2008: aspects of direct restorations, endodontics and bleaching.

OBJECTIVE: To investigate, by postal questionnaire, aspects of the selection and use of direct restorative materials, endodontic techniques and approaches to bleaching by general dental practitioners in the UK, and to compare and contrast the findings with those of a related study reported in 2004. METHODS: A questionnaire comprising 18 questions, each of a number of elements, was sent to 1,000 general dental practitioners in the UK, selected at random from the Dentists Register. Non-responders were sent a second copy of the questionnaire after a period of four weeks had elapsed. RESULTS: A total of 662 useable responses were returned, giving a response rate of 66%. Key findings included: dental amalgam was found to be the most commonly used material in the restoration of occlusoproximal cavities in premolar (59% of respondents) and molar teeth (75% of respondents); glass-ionomer cements and related materials were applied extensively in the restoration of deciduous molars (81% of respondents) and for the luting of indirect restorations (67% of respondents); the use of rubber dam was limited, in particular as an adjunct to procedures in operative dentistry (18% of respondents); relatively few respondents used preformed stainless steel crowns, and among the users only occasionally in the restoration of deciduous molars (23%); and bleaching, predominantly home-based (nightguard) vital bleaching (81% of respondents) was widely practised. CONCLUSION: It is concluded that, for the practitioners surveyed, factors other than best available evidence influenced various aspects of the use of direct restorative materials and the clinical practice of endodontics. As a consequence, many of the features of general dental practice revealed in the process of the investigation were at variance with teaching in dental schools. Bleaching, in particular home-based (nightguard), vital bleaching, was provided by >80% of respondents, indicating widespread interest among patients in enhanced dental attractiveness.

Factors influencing patient satisfaction with dental appearance and treatments they desire to improve aesthetics.

BACKGROUND: We assessed factors influencing patients' satisfaction with their dental appearance and the treatments they desired to improve dental aesthetics. METHODS: A cross-sectional study was performed out among 235 adult patients who visited the Hospital Universiti Sains Malaysia dental clinic. A structured, interviewer-guided questionnaire was used to identify patient satisfaction with their general dental appearance, cosmetic elements and desired treatments. RESULTS: The 235 patients consisted of 70 males (29.8%) and 165 females (70.2%), of mean age 31.5 years (SD 13.0). Of these patients, 124 (52.8%) were not satisfied with their general dental appearance. In addition, 132 patients (56.2%) were not happy with the color of their teeth, 76 (32.3%), regarded their teeth were poorly aligned, 62 (26.4%), as crowded and 56 (23.4%) protruded. Dissatisfaction with tooth color was significantly higher in female than in male patients (odds ratio [OR] of 1.99 (95% confidence interval [CI] 1.13-3.50). Tooth whitening was the treatment most desired by patients (48.1%). Results of multiple logistic regression analysis showed that patient dissatisfaction with general dental appearance was significantly associated with female gender (OR = 2.18; 95% CI: 1.18-4.03), unhappiness with tooth color (OR = 3.05; 95% CI: 1.74-5.34) and the opinion that their teeth protruded (OR = 2.91, 95% CI: 1.44-5.91). CONCLUSIONS: Most patients in this study were not satisfied with their dental appearance with a greater percentage of females expressing dissatisfaction than males. An age was not associated with satisfaction. Unhappiness with tooth color and feelings of having protruding teeth also had a significant negative influence on patient satisfaction with general dental appearance.

An investigation into the current practice of tooth whitening in a southern English city in the context of associated legal issues.

AIMS: This investigation examined the current practice of tooth whitening carried out by a sample of dentists and beauty therapists from Portsmouth in the context of the relevant law. METHODS: A random sample of dentists and all beauty salons in Portsmouth were invited to respond to two postal questionnaires, one for dentists and one for beauty salons. These questionnaires were used to assess whether tooth-whitening services were offered and if so, details of products and techniques employed. The findings were analysed and compared with the current United Kingdom law on tooth whitening. RESULTS: One hundred and seventy-nine dentists (88%) and 76 (75%) beauty salons responded. One hundred and nineteen (66%) of the responding dentists and eight (11%) responding beauty salons provided in-house and/or take-home tooth-whitening services. The vast majority employed whitening agents containing or releasing hydrogen peroxide at a concentration greater than that permitted by the Cosmetic Products (Safety) Regulations 2008. CONCLUSIONS: The current practice of tooth whitening by the dentists and beauty salons surveyed in this study is at odds with the criminal law that has been developed in order to safeguard consumers in relation to the products employed and the individuals carrying out the practice of dentistry. The practice also raises civil law issues, and compensation may be necessary in the event of injury. A change in the law, based on a scientific background and professional standards of care, is required at both European and domestic levels in order to align reasonable practice with the law, while upholding patient safety.

Preoccupation with one's appearance: a motivating factor for cosmetic dental treatment?

BACKGROUND: It has been estimated that among patients presenting for cosmetic treatments up to 15% suffer from Body Dysmorphic Disorder (BDD), a psychiatric condition characterised by a preoccupation with an imagined defect in appearance. OBJECTIVES: The main purpose of the current study was to establish the relationship between presence of BDD characteristics and interest in aesthetically motivated dental treatments. METHODS: Data were obtained by means of a survey within a sample of 879 Dutch citizens of 16 years and older. Characteristics of BDD were assessed based on DSM-IV criteria. RESULTS: Only one of the BDD features (ie a preoccupation with a defect of appearance) emerged as a significant predictor of undergoing cosmetic dental treatments. Patients with such preoccupation were nine times more likely to consider tooth whitening, and six times more likely to consider orthodontic treatment. They were also five times more likely to be dissatisfied about their most recent treatment. CONCLUSIONS: The results suggest that preoccupation with one's physical appearance is a motivating factor for undergoing certain types of cosmetic dental procedures.

Accelerated aging effects on color and translucency of bleaching-shade composites.

PURPOSE: This study was performed to evaluate the influence of accelerated aging on the color and translucency parameter (TP) of bleaching-shade resin composites. MATERIALS AND METHODS: Thirty-three bleaching shades and two control conventional shades of microhybrid (MH) and microfill (MF) resin composite specimens (n = 5) were aged in an accelerated aging chamber set to standard CAM 180 cycles. One side of each specimen was evaluated for surface color and TP changes compared with baseline in increments of 150 kJ/m2 for intervals up to 450 kJ/m2 using a spectrophotometer. A deltaE* > or = 3.7 was considered to be a poor match, and the total TP range was divided into three equal parts representing low, medium, and high translucency. Data were analyzed with analysis of variance. RESULTS: Compared to the baseline, deltaL*, deltaa*, deltab*, and deltaE* ranges at 450 kJ/m2 were -0.8 to 5.0, -0.6 to 1.2, -8.3 to 0.0, and 0.7 to 8.6 for MH and 0.2 to 1.3, 0.1 to 1.3, -2.5 to 1.1, and 1.7 to 2.7 for MF composites. Scheffé's S intervals (p = .05) for comparisons of deltaL*, deltaa*, deltab*, and deltaE* values of MH composites between baseline and 450 kJ/m2 were 1.6, 0.6, 1.7, and 1.5, respectively. Corresponding Tukey-Kramer intervals for MF composites were 0.7, 0.3, 0.6, and 0.6, respectively. TP values at baseline ranged from 0.9 to 4.3 for MH and from 1.4 to 2.2 for MF composites, whereas deltaTP for baseline minus 450 kJ/m2 ranged from -1.1 to 1.7 for MH and from -0.1 to 0.3 for MF composites. Scheffé's S interval (p = .05) for comparisons of deltaTP values of MH composites for baseline minus 450 kJ/m2 was 1.0. Corresponding Tukey-Kramer interval for MF composites was 0.4. CONCLUSIONS: Aging-dependent color changes at 450 kJ/m2 were above the limit that indicated a poor match for 18/26 MH, while corresponding values for microfills were within acceptable range. Accelerated aging generally caused decreases in L* (specimens became darker) and a* values (specimens became redder), while b* values increased (specimens became more chromatic) for both MH and MF composites. TP was relatively stable during aging for both MH and MF composites.

Effects of three concentrations of carbamide peroxide on the structure of enamel.

Carbamide peroxide bleaching agents have raised important questions on their potential adverse effects on the structure of enamel. The purpose of this study was to examine the effects of three carbamide peroxide bleaching agents in different concentrations (10, 16 and 35%) on the structure of enamel. Forty enamel slabs prepared from human third molars were divided equally among four groups. The specimens in the first and second group were subjected to 10% or 16% carbamide peroxide for 8 h per day for 6 weeks. Thirty-five percent carbamide peroxide was applied to the third group for 30 min a day for a 4 day period according to the manufacturers recommendation. The fourth group served as the control and was kept in artificial saliva during the test period. At the completion of the treatment, all the specimens were examined by infrared absorbtion spectroscopy and X-ray diffraction analysis. The results revealed that 10% or 16% carbamide peroxide did not seem to effect the structure of enamel, whereas 35% carbamide did affect the structure. The use of lower concentrations of carbamide peroxide (10-16%) is recommended over higher concentrations (35%) to avoid changes to the enamel.

Bleaching teeth: report of a survey, 1997.

Vital tooth bleaching is here--it is a viable, predictable concept providing great patient acceptance and satisfaction. Practitioners are advised to educate patients routinely about bleaching and to upgrade themselves and their auxiliary staff to be able to accomplish all aspects of bleaching.

In vitro adherence of bacteria to bleached or unbleached enamel surfaces.

The purpose of this in vitro study was to evaluate the effects of three 10% carbamide peroxide bleaching agents on adherence of bacteria to tooth enamel surface. Enamel specimens were subjected to one of three carbamide peroxide solutions for 8 h per day for 30 days. Control specimens were kept in saline solution. Profilometer evaluation of surface roughness was performed on all specimens. The adherence of Streptococcus mutans was determined bacteriologically. There was no significant difference in surface roughness between the untreated and treated enamel specimens but a statistically significant difference was found in the adherence of S. mutans to bleached and unbleached enamel specimens. Specimens treated with Opalescence showed the highest adherence.