Near-infrared imaging of demineralization on the occlusal surfaces of teeth without the interference of stains

Most new caries lesions are found in the pits and fissures of the occlusal surface. Radiographs have extremely low sensitivity for early occlusal decay, and by the time the lesion is severe enough to appear on a radiograph, it typically has penetrated well into the dentin and surgical intervention is required. The occlusal surfaces are often heavily stained, and visual and tactile detection have poor sensitivity and specificity. Previous near-infrared imaging studies at wavelengths beyond 1300 nm have demonstrated that stains are not visible and demineralization on the occlusal surfaces can be viewed without interference from stains. The objective of our study is to determine how the contrast between sound and lesion areas on occlusal surfaces varies with wavelength from the visible to 2350 nm and determine to what degree stains interfere with that contrast. The lesion contrast for reflectance is measured in 55 extracted teeth with suspected occlusal lesions from 400 to 2350 nm employing silicon and indium gallium arsenide imaging arrays. In addition, the lesion contrast is measured on 25 extracted teeth with suspected occlusal lesions from 400 to 1600 nm in reflectance and from 830 to 1400 nm in transillumination before and after stains are removed using a ultrasonic scaler. The highest lesion contrast in reflectance is measured at wavelengths >1700  nm. Stains interfere significantly at wavelengths <1150  nm (400 to 1150) for both reflectance and transillumination measurements. Our study suggests that the optimum wavelengths for imaging decay in the occlusal surfaces are >1700  nm for reflectance (1700 to 2350 nm) and near 1300 nm (1250 to 1350 nm) for transillumination.

The Smile Esthetic Index (SEI): A method to measure the esthetics of the smile. An intra-rater and inter-rater agreement study

PURPOSE

To propose a method to measure the esthetics of the smile and to report its validation by means of an intra-rater and inter-rater agreement analysis.

MATERIALS AND METHODS

Ten variables were chosen as determinants for the esthetics of a smile: smile line and facial midline, tooth alignment, tooth deformity, tooth dischromy, gingival dischromy, gingival recession, gingival excess, gingival scars and diastema/missing papillae. One examiner consecutively selected seventy smile pictures, which were in the frontal view. Ten examiners, with different levels of clinical experience and specialties, applied the proposed assessment method twice on the selected pictures, independently and blindly. Intraclass correlation coefficient (ICC) and Fleiss' kappa) statistics were performed to analyse the intra-rater and inter-rater agreement.

RESULTS

Considering the cumulative assessment of the Smile Esthetic Index (SEI), the ICC value for the inter-rater agreement of the 10 examiners was 0.62 (95% CI: 0.51 to 0.72), representing a substantial agreement. Intra-rater agreement ranged from 0.86 to 0.99. Inter-rater agreement (Fleiss' kappa statistics) calculated for each variable ranged from 0.17 to 0.75.

CONCLUSION

The SEI was a reproducible method, to assess the esthetic component of the smile, useful for the diagnostic phase and for setting appropriate treatment plans.

Color masking of developmental enamel defects: a case series

Developmental defects involving color alteration of enamel frequently compromise the esthetic appearance of the tooth. The resin infiltration technique represents an alternative treatment for color masking of these lesions and uniformization of tooth color. This technique is considered relatively simple and microinvasive, since only a minimal portion of enamel is removed. This article illustrates the color-masking effect with resin infiltration of fluorosis and traumatic hypomineralization lesions with a case series. The final esthetic outcomes demonstrated the ability of the resin infiltrant to mask the color of white developmental defect lesions, resulting in satisfactory clinical esthetic improvements. However, in more severe cases, the color-masking effect was not complete.

Use of high-magnification loupes or surgical operating microscope when performing prophylaxes, scaling or root planing procedures

The use of high-level magnification (6-8x loupes magnification, or higher degrees of magnification provided by the surgical operating microscope), combined with head-mounted, coaxial lighting, may improve the ability of a dentist or dental hygienist to perform prophylaxis or scaling and root planing procedures, compared to the performance of these tasks using unaided vision or entry-level (2.5x) magnification, combined with overhead operatory lighting. A magnified view of the supragingival contours of a tooth surface facilitates visualizing the dimensions and curvature of the unseen sub-gingival tooth surfaces, which facilitates detection and removal of calculus that is located on these subgingival surfaces. Improved calculus removal ability may lead to better periodontal disease outcomes.

Staining of dentin from amalgam corrosion is induced by demineralization

PURPOSE

To evaluate the effect of artificial demineralization upon color change of dentin in contact with dental amalgam.

METHODS

Sound human molars (n = 34) were embedded in resin and coronal enamel was removed. Dentin was exposed to artificial caries gel (pH 5.5) at 37 degrees C for 12 weeks (n = 24). Non-demineralized teeth served as controls (n = the 10). A dispersive high-Cu amalgam or conventional low-Cu amalgam was condensed onto dentin surfaces of all groups. After 10 weeks storage in saline, amalgam was removed and teeth were cut into three slices. Surfaces were inspected under optical microscopy and photographed.

RESULTS

Penetration of black pigments was observed in dentin underneath both high-Cu and low-Cu amalgams in demineralized specimens. Black deposits were unevenly distributed and observed predominantly in dentin near to pulp horns. Discoloration was not limited to outer demineralized dentin but extended beyond this zone. Evenly distributed bluish-green discoloration was observed underneath all high-Cu amalgam specimens independent of demineralization.

Are there metallic traces in black extrinsic dental stain?

OBJECTIVE

The detection of ferric ions in samples of black extrinsic dental stain led to the idea that it is comprised of insoluble ferric compounds. The present study examined the chemical composition of black extrinsic dental stain.

METHOD AND MATERIALS

Plaque was collected from 17 children with black extrinsic dental stain (study group A) and from 15 children without black extrinsic stain (control group), using sterile graphite curettes; and from 4 children with black extrinsic stain (study group B), using a standard sterile metal curette. Samples were analyzed with a scanning electron microscope (SEM) and subjected to quantitative chemical analysis (energy dispersive spectrometry).

RESULTS

Except for calcium and phosphorus levels, no significant differences were found between the chemical composition of black extrinsic dental stain and dental plaque. Metallic ions were not detected in samples collected with a graphite curette (study group A), but were detected in samples collected with a metal curette (study group B).

CONCLUSION

Metallic ions do not seem to be the origin of black extrinsic dental stain. Previous reports of the presence of metallic ions are probably due to contamination of the samples by the collection method.

Guidelines for the selection of tooth whitening products amongst those available on the market

BACKGROUND

Several tooth whiteners are available on the market, and the ideal choice should be determined by efficacy and optimal clinical results.

OBJECTIVES

The purpose of this study was to compare the reported clinical success rates of different tooth whitening products.

SEARCH STRATEGY

The relevant literature (1998 - 2011) was studied, using as sources the databases: Google Scholar, Science Direct, Medline and Pubmed.

SELECTION CRITERIA

The material was clearly identified, the manufacturers' instructions were respected and the sample size stated.

RESULTS AND CONCLUSIONS

This descriptive report on 49 papers focuses on the total colour change, measured with a calibrated shade guide and also numerically (colourimeter, chromameter or spectrophotometer), the relapse of the colour change and tooth sensitivity. In general, the dentist-supervised at-home bleaching and the in-office treatment gave approximately the same initial percentage improvement of tooth whitening. However, the relapse after a four week or longer period was significantly higher for the in-office treatment. The treatment of choice should be a dentist supervised at-home bleaching product which generally contains approximately 10% carbamide peroxide applied over about 14 days for about eight hours per night. Tooth sensitivity should not be a general problem although some subjects might choose to discontinue treatment as a result of sensitivity.

The influence of a continuous increase in thickness of opaque-shade composite resin on masking ability and translucency

OBJECTIVES

This study was conducted to determine the minimum thickness of opaque-shade composite resin required to mask discolored tooth structures or darkness of the oral cavity and to determine the effect of the brand and shade of composite resins on masking ability and translucency.

MATERIALS AND METHODS

Discs and beveled specimens were manufactured using six opaque-shade light-curing composite resins (Charisma, Heraeus Kulzer; Estelite Sigma Quick, Tokuyama; Gradia Direct Anterior, GC). The discolored tooth structures and darkness of the oral cavity were reproduced using background tiles. The disc specimen colors were measured using a spectroradiometer by increasing the thickness of the beveled specimens on the backing by 0.05 mm in series, and color difference (ΔE*(ab)) and translucency parameter (TP) were calculated.

RESULTS

The thicknesses of opaque-shade composite resins that masked the C4 shade and black backings were 0.80-1.45 and 1.85-2.00 mm, respectively. Overall, the ΔE*(ab) and TP values decreased as the thickness of the opaque-shade composite resins increased. When the shades of the composite resins were identical, the TP decreased in the order of Charisma, Estelite Sigma Quick and Gradia Direct Anterior. When the brand was fixed, the TP was higher in the OA3 shade than in the OA2 shade. A significant correlation was seen between ΔE*(ab) and TP (p < 0.05).

CONCLUSIONS

The brands and shades of the composite resins were shown to have a clear effect on TP, but an inconsistent tendency for ΔE*(ab).

Safety and efficacy of a high-adhesion whitening strip under extended wear regimen

OBJECTIVES

This randomized, parallel group, single centre clinical trial was conducted to evaluate the safety and compare the whitening efficacy for an extended wear of an experimental 9.5% H₂O₂ high-adhesion whitening strip, relative to a marketed 10% H₂O₂ control strip.

METHODS

Twenty-nine eligible adult volunteers were randomly assigned to either a treatment series with an experimental 9.5% H₂O₂ high-adhesion whitening strip at home for 2h, once a day, for 8 days; or a marketed 10% H₂O₂ whitening strip for 30 min, on a similar daily regimen. Tooth color/whitening progression was recorded under standardized lighting conditions at baseline, day 3, day 5, and day 9, via digital imaging. Outcomes were reported using the CIELAB system. Usage safety was also assessed at each follow-up visit. Whitening efficacy for each group was investigated using a paired-difference t-test. The treatment groups were compared among each other using the analysis of covariance, with the baseline value and age as the covariates.

RESULTS

Both treatment groups demonstrated statistically significant mean color improvement from baseline for b* (yellow ness) and L* (lightness) at each post-baseline visit. In addition, the 2-h high-adhesion strips demonstrated significantly greater improvement in b* and L* relative to the 30-min strip group at each follow-up visit.

CONCLUSIONS

The 2-h regimen for the 9.5% H₂O₂ high-adhesion whitening strip was more efficient for tooth whitening than the 30-min regimen of 10% H₂O₂ whitening strip. Both treatments were well tolerated and the use of the test products during the study time frame was considered safe.

CLINICAL RELEVANCE

Extending the daily wear time of whitening strips can improve the efficacy of the treatment and ultimately shorten the length of the treatment without any significant adverse effects.

Clinical color intensity of white spot lesions might be a better predictor of enamel demineralization depth than traditional clinical grading

INTRODUCTION

The aims of this study were to calculate the volume of white spot lesions by using microcomputed tomography and to determine which clinical attribute of the white spot lesion could better predict its volume: the clinically visible white spot lesion surface area or its color intensity.

METHODS

White spot lesions were induced in 8 patients in vivo on 23 healthy premolars destined for extraction during orthodontic treatment by using specially designed plaque-retaining orthodontic bands. After 7 weeks, the premolars were extracted. After extraction, the resulting white spot lesions were photographed and clinically graded. The teeth were analyzed with microcomputed tomography.

RESULTS

After 7 weeks, 70% of the teeth developed clinical white spot lesions. Clinically, the size of the lesions varied from minor to severe. Their volumes varied from 0 to 1.2931 mm(3). The traditional grades for white spot lesions correlated significantly with color intensity. A significant correlation was found between white spot lesion color intensity and lesion volume. This correlation was found to be better than that between the white spot lesion clinical score and lesion volume.

CONCLUSIONS

Our results indicate that white spot lesion color intensity might predict the depth of enamel demineralization as well as or better than traditional white spot lesion scoring. Therefore, the dentist could use this information when planning treatment for white spot lesions.

Rehydration of a reattached fractured tooth fragment after prolonged dehydration

Crown fractures of the anterior teeth are one of the most common outcomes of trauma to the orofacial region. The reattachment of dental fragments is a conservative treatment and should be considered a primary treatment choice in the restoration of anterior tooth fractures. This article presents a clinical technique for the restoration of a fractured maxillary lateral incisor by reattaching the tooth fragment that was kept in dry conditions for five days with the aid of adhesive dentistry. The esthetic compromise of white color (due to excessive dehydration of the segment) was reconciled after one month of service in the mouth by regaining the natural color by rehydration. The one-year clinical evaluation revealed a successful outcome for this technique, and the patient was pleased with the esthetic results of the conservative treatment modality.

Stain removal efficacy of a novel dentifrice containing papain and Bromelain extracts--an in vitro study

OBJECTIVE

To assess the in vitro stain removal efficacy of a novel commercially available dentifrice.

MATERIALS AND METHODS

Twenty four human molar teeth (12 in test and 12 in control group) were cut to obtain enamel specimens approximately 9 mm(2) and placed on a microscopic slide using mounting adhesive. They were cycled in human saliva, staining model and dried for brushing regimen using a customized brushing apparatus. Lightness values were recorded at baseline, after staining and after brushing regimen using Adobe Photoshop software. Stain removal efficacy was tested using the either of the two dentifrice slurries for 2 one minute brushing cycles.

RESULTS

The mean lightness increment for test and control after brushing regimen was 13.7 ± 6.35 and 3.16 ± 1.29 respectively. There was statistically significant difference in percentage removal of stains for test and control groups (66.99 ± 9.57 and 25.89 ± 16.2 P < 0.001).

CONCLUSION

There was significant stain removal with new whitening dentifrice when compared with control. Further clinical trials are recommended to evaluate this significant difference.

[Oral cavity features in patients suffering from osteogenesis imperfecta]

Osteogenesis Imperfecta (OI) is a rare hereditary connective tissue disorder. This pathology is characterized by disruption of biosynthesis of Type I collagen, and production of limited amount of defective and imperfect collagens. This causes decrease in bone mass of human body, bones become fragile and brittle, resulting in unreasonable multiple fractures. Reportedly, number of patients with OI ranges between 32-38 in Georgia. However, exact number of patients, including children and their parents, is unknown. Dentinogenesis Imperfecta (DI; DGI) and skeletal malocclusion occupy special place in varied spectrum of OI clinical symptoms. We studied 14 patients: 9 women (64.3%), 5 men (35.7%) and divided them in three age groups: I - 2.5-6 years - period of primary dentition (28.6%), II - 6-14 years - period of changing teeth dentition (35.7%) and III - above 14 years - period of permanent dentition (35.7%). 28.5% of screened patients had one of the symptoms of DI, such as tooth discoloration. Discoloration of primary teeth was revealed in 4 patients (primary dentition). Another symptom of DI, such as early abrasion, was detected in 5 patients i.e. 35.71%. This was divided in the following manner: I age group - 3 cases, II and III age groups - 1-1 cases. It was also observed that early abrasion of primary teeth prevails over permanent. One of DI's radiographic symptoms, such as peculiar form of teeth crown and root, was revealed in 21.4% or in 3 patients, 2 of whom had bulbous crown, and the third one deformed (curved) root. Peculiar characteristics of DI, such as increased constriction of the coronal-radicular junction, obliterated pulp chamber, short and narrow roots, were not observed in the patients examined. Interesting characteristic of DI, such as periapical destruction of intact tooth root, was revealed in the form of bone defect in 7.1% of those examined (1 patient). Therefore, out of examined 14 patients with OI - DI had 6 patients or 42.85% of cases. Also, interesting observation was revealed - DI is more common in primary teeth (66.66%) than in permanent (33.33%). Radiographic examination - orthopantomography - revealed secondary osteoporosis of jaw bones in 100% of cases. Mucous tissue of examined patients is within normal range. Among examined patients, 1 case of adenty, 1 case of retention and 1 case of overcomplex tooth were revealed. According to current literature, it is unknown whether there is a lgical relationship between adenty, retention, overcomplex teeth and OI. This will be defined by future research.

Prediction of color change after tooth bleaching using fuzzy logic for Vita Classical shades identification

Tooth bleaching is becoming increasingly popular among patients and dentists since it is a relatively noninvasive approach for whitening and lightening teeth. Instruments and visual assessment with respect to commercial shade guides are currently used to evaluate tooth color. However, the association between these procedures is imprecise and the degree of color change after tooth bleaching is known to vary substantially between studies; there are currently no objective guidelines to predict the effectiveness of a tooth-bleaching treatment. We propose a new methodology based on fuzzy logic as a natural means of representing the imprecision present when modeling the color change produced by a tooth-bleaching treatment on the basis of a tooth's initial chromatic values. This system has the advantage of producing a set of interpretable fuzzy rules that can subsequently be used by scientists and dental practitioners. The fuzzy system obtained has the special characteristic whereby the rule antecedents correspond to prebleaching shades of the well-known Vita commercial shade guide. Additionally, the rule consequents directly correspond with the expected CIELAB postbleaching values for each Vita shade, thanks to a modification of the system's inference structure. Finally, the values of these postbleaching CIELAB coordinates have been associated with Vita shades by evaluating their respective membership functions, thereby approximating which posttreatment Vita shades are to be expected for each prebleaching shade.

Color stability of bleached teeth over time: an in vitro study

OBJECTIVE

The aim of this study was to evaluate the in vitro color stability of bleached teeth by means of a 6-day staining procedure.

MATERIAL AND METHODS

20 caries-free randomly divided into two groups. Test group: a bleaching agent (Zoom 2, Discus Dental) was applied to the labial surfaces following the manufacturer's instructions.

CONTROL GROUP

no bleaching treatment. using a thermo-cycling device, all teeth were alternately immersed in a 0.9% saline solution at 37 °C for 1 hour, and in a coffee solution at 55 °C for another hour, in order to simulate the natural tooth-staining process. This procedure was repeated 12 times a day for 6 days. Teeth were polished once a day with a rubber cup and polishing paste. CIELAB color variables (L, a, b) were assessed by means of a spectrophotometer (VITA Easyshade®) and a custom alignment device at baseline, after bleaching, and once a day throughout the 6-day staining treatment. The bleaching result and the color stability of bleached and control group teeth were assessed by matched pair t test and MANOVA.

RESULTS

The bleaching agent had a significant whitening effect. The staining treatment did not produce any significant color change on bleached teeth, which maintained the same whiteness achieved after the bleaching treatment. The staining treatment did not produce any significant color change on control teeth. The two groups showed significant differences in both whiteness and lightness changes as a result of the polishing treatment.

CONCLUSIONS

The Zoom 2 whitening agent produced immediate and long-lasting bleaching results, even if the reduction of b value mainly occurred 24 and 48 hours after the bleaching treatment.

The parallel stratification masking technique: an analytical approach to predictably mask discolored dental substrate

Discolored dental substrates continue to challenge the restorative team when ultraconservative treatment modalities are chosen. An innovative laboratory concept--the parallel stratification masking technique--has been developed in order to achieve maximum preservation of dental hard tissues and predictably accomplish a desirable esthetic outcome. The major advantages of this technique are that the ceramist is able to: a)identify and map the discolored dental substrate, b)predictably mask the discolored dental substrate, and c) assess the appropriate masking efficacy of the fabricated restoration prior to laboratory delivery to the dentist in cases of bonded porcelain restorations.

Evaluation of radiographs, clinical signs and symptoms associated with pulp canal obliteration: an aid to treatment decision

Pulp canal obliteration (PCO) is a sequela of tooth trauma. The dental clinician faced with this condition has to make a difficult decision. The aim of this study was to evaluate the clinical signs and symptoms associated with teeth with PCO and to assess the status of the periapical tissues using the periapical index (PAI) as an aid in making a treatment decision. The study included teeth diagnosed with PCO in patients with a history of traumatic injury to the involved teeth. Histories of associated signs and symptoms including pain, swelling and drainage from a sinus tract were elicited. Tooth color, sensibility to electric pulp testing, mobility and percussion tenderness were recorded. The periapical status was assessed using the PAI. Two hundred and seventy-six teeth were diagnosed with PCO. One hundred and fifty-seven (56.9%) and 119 (43.1%) demonstrated partial or total PCO, respectively. Yellow discoloration presented most frequently, occurring in 186 (67.4%) teeth. Sixty-two (33.3%) of these had developed periapical lesions and reacted negatively to sensibility testing. Fifty-seven (30.7%) of these teeth presented radiographically with a normal periapical appearance and reacted normally to sensibility testing, whereas 67 (36.0%) presented with small changes in the periapical bone pattern and reacted in the high normal range to sensibility testing. Teeth with PAI scores < or =2 presented with occasional spontaneous pain. Teeth with PAI scores > or =3 presented with clinical symptoms and signs ranging from pain on percussion to spontaneous pain, and slight swelling to sinus tract drainage. Based on the findings of this study, endodontic treatment should be initiated in teeth with tenderness to percussion, PAI scores > or =3 and a negative response to sensibility testing.

Regional odontodysplasia: morphological, ultrastructural, and immunohistochemical features of the affected teeth, connective tissue, and odontogenic remnants

PURPOSE

Regional odontodysplasia (RO) is a rare developmental odontogenic defect. The affected teeth are described as "ghost teeth," due to malformation of dentin, enamel, and cementum. The purpose of this study was to describe the ultrastructural characteristics of the affected teeth as well as the immunohistochemical features of the soft tissue associated with 2 cases of regional odontodysplasia.

METHODS

Two cases diagnosed as RO were included on the study. After diagnosis, affected teeth and associated soft tissue were surgically removed from both patients and processed for light and scanning electron microscopy (SEM) analysis. For light microscopy, the specimens were decalcified in 5% nitric acid for 10 to 16 days and stained with hematoxylin and eosin. For SEM studies, specimens were cleaned with diamond paste and, after polishing, treated with 37% phosphoric acid for 5 minutes and covered by a thin layer of metallic gold. Soft tissues covering and surrounding the extracted teeth were routinely processed, and submitted to immunohistochemical reactions against pan-cytokeratins, cytokeratin 19, vimentin, laminin and collagen IV.

RESULTS

Both enamel and dentin showed gross alterations, including hypomineralization and discoloration, being more prominent on the coronal structures than the radicular structures. Ultrastructural features included alterations on the prismatic enamel surface, dentinal grooves, interglobular dentin, and hypoplastic and hypocalcified dental hard tissues. The soft gingival and alveolar tissue surrounding and covering the affected teeth showed calcifications and odontogenic remnants, positive for cytokeratin 19, laminin, and collagen IV.

CONCLUSIONS

Enamel and dentin are grossly altered in regional odontodysplasia, while cementum is less affected, and soft-tissue calcifications are associated with odontogenic cytokeratin-positive epithelial remnants, in addition to mesenchymal components.

Influence of a desensitizing agent on efficacy of a paint-on bleaching agent

PURPOSE

To evaluate the influence of a desensitizing agent (VivaSens) on efficacy of a paint-on bleaching agent (VivaStyle Paint On Plus).

METHODS

Bleaching was performed for 7 days with VivaStyle Paint On Plus. The varnish was applied twice a day for 10 minutes each. 80 subjects were included in the study and randomly distributed in two groups (n = 40) according to exposed cervical dentin and perceived hypersensitivities. Group A used VivaStyle without VivaSens while Group B used VivaStyle Paint On Plus after a single application of VivaSens. Tooth color was assessed on facial surfaces of first upper incisors with Vita shade guide at baseline and 10 days after bleaching therapy. Sensitivity, with intensity graded from 0 (no sensitivity) to 10 (high sensitivity), was assessed chair-side using a blow of air at baseline, at the end of therapy (7 days) and 10 days after bleaching therapy. Statistical evaluation was performed with non parametric ANOVA.

RESULTS

Thirteen subjects dropped out of the study; six due to gingival burning sensation (A: 3; B: 3) related to the bleaching regimen and seven due to lack of compliance. Directly after completion of bleaching therapy, tooth color had changed significantly compared to baseline in both treatment groups without difference among the groups. Color changes (Delta) according to Vita shade guide were as follows (mean +/- standard deviation): Group A: Delta 2.7 +/- 1.0, Group B: Delta 2.8 +/- 0.9. After bleaching (7 days) the intensity of tooth hypersensitivity (mean +/- standard deviation) was increased significantly compared to baseline in both groups (P < 0.05): Group A: 1.58 +/- 1.91 (baseline: 0.4 +/- 0.5); Group B: 1.3 +/- 1.8 (baseline: 0.5 +/- 0.7). The number of subjects reporting tooth hypersensitivity increased in Group A by 5 (n = 13) and in Group B by 1 (n = 10) subject. Although degree of hypersensitivities and number of subjects with hypersensitivities were lower in Group B, there was no significant difference between the groups.

Classification of clinical attributes in tooth appearance

In this article, the author proposes objective definitions in one area of tooth appearance that has historically been subjective and relative, without standardized descriptions. This concept has evolved from the need for a classification system that would enable defined, reliable, and repeatable communication between the dentist and ceramist. Following detailed observations of natural teeth, categories of appearance attributes have been developed with classifications assigned in each category. These definitions are comprehensive and provide a utilitarian description of all essential features that comprise tooth appearance other than shade. Subjective vagaries in the communication process between dentist and ceramist can be eliminated while the time, effort, and cost associated with delivering high-quality aesthetic restorations can be reduced.

Measurement of stain on extracted teeth using spectrophotometry and digital image analysis

AIM

The aim of this study was to assess the reliability and validate a customized image analysis system, designed for use within clinical trials of general dental hygiene and whitening products, for the measurement of stain levels on extracted teeth and to compare it with reflectance spectrophotometry.

METHOD

Twenty non-carious extracted teeth were soaked in an artificial saliva, brushed for 1 min using an electric toothbrush and a standard toothpaste, bleached using a 5.3% hydrogen peroxide solution and cycled for 6 h daily through a tea solution. CIE L* values were obtained after each treatment step using the customized image analysis system and a reflectance spectrophotometer. A statistical analysis was carried out in SPSS.

RESULTS

Fleiss' coefficient of reliability for intra-operator repeatability of the image analysis system and spectrophotometry was 0.996 and 0.946 respectively. CIE L* values were consistently higher using the image analysis compared with spectrophotometry, and t-tests for each treatment step showed significant differences (P < 0.05) for the two methods. Limits of agreement between the methods were -27.95 to +2.07, with a 95% confidence of the difference calculated as -14.26 to -11.84. The combined results for all treatment steps showed a significant difference between the methods for the CIE L* values (P < 0.05).

CONCLUSION

The image analysis system has proven to be a reliable method for assessment of changes in stain level on extracted teeth. The method has been validated against reflectance spectrophotometry. This method may be used for pilot in vitro studies/trials of oral hygiene and whitening products, before expensive in vivo tests are carried out.

Daytime use of a custom bleaching tray or whitening strips: initial and sustained color improvement

PURPOSE

To compare the clinical response of 6% hydrogen peroxide whitening strips and a 10% carbamide peroxide custom tray system under common daytime usage conditions, in an Italian dental research center.

METHODS

Informed consent and baseline measurements were collected, and 43 healthy adults were randomly assigned to 6% hydrogen peroxide whitening strips (Crest Whitestrips) or the 10% carbamide peroxide custom tray (Opalescence 10%). The maxillary arch was treated twice daily for 30 minutes at-home. Treatment was discontinued after 2 weeks, and subjects were monitored for an additional 4 weeks. Efficacy (initial and sustained) was measured objectively from standard digital images of the maxillary facial tooth surfaces using the international CIELAB system. Safety was assessed from interview and examination. Treatments were compared after 2 weeks (end-of-treatment) and 6 weeks (4 weeks post-treatment) using analysis of covariance methods.

RESULTS

Both groups exhibited color improvement at the Week 2 end-of-treatment visit. For yellowness, mean (SD) Deltab* at Week 2 was -2.10 (0.70) for the strip group and -1.61 (1.03) for the tray group. For lightness, mean (SD) DeltaL* at Week 2 was 1.25 (0.92) for the strip group and 1.17 (1.19) for the tray group. Compared to Week 2, the strip group retained 89-92% of the initial Deltab* and DeltaL* color improvement at Week 6 (4 weeks post-treatment), while the tray group had 80-90%. Groups differed significantly (P< 0.05) on end-of-treatment and post-treatment Deltab*, favoring the strips. Both daytime treatments were well-tolerated, with minor tooth sensitivity and oral irritation representing the most common findings.

Clinical trial of long-term color stability of hydrogen peroxide strips and sodium percarbonate film

PURPOSE

To compare initial and sustained clinical response of 6% hydrogen peroxide whitening strips and a 19% sodium percarbonate film in a randomized controlled trial.

METHODS

Informed consent was obtained, after which 72 subjects were randomized to 6% hydrogen peroxide whitening strips (Crest Whitestrips), 19% sodium percarbonate brush-applied gel that dries as a film (Crest Night Effects), or placebo brush-applied gel without peroxide. Efficacy (digital imaging) and safety (clinical examination and interview) were assessed after 2 weeks treatment, and again at up to eight post-treatment timepoints over an 18-month post-treatment period.

RESULTS

For Deltab* (yellowness), end-of-treatment adjusted means +/- standard errors (SE) were -2.37 +/- 0.088 for the strip group, -1.36 +/- 0.091 for the film group, and -0.08 +/- 0.090 for the placebo group. For DeltaL* (brightness), end-of-treatment adjusted means +/- SE were 2.40 +/- 0.121 for the strip group, 1.47 +/- 0.125 for the film group, and 0.06 +/- 0.122 for the placebo group. Groups differed significantly (P< 0.02) at end-of-treatment and throughout post-treatment. All treatments were well-tolerated, both peroxide-containing systems exhibited appreciable color retention throughout the 18-month post-treatment period, and there were no meaningful, persistent adverse events seen with long-term follow-up.

Randomized clinical trial comparing whitening strips, paint-on gel and negative control

PURPOSE

To evaluate efficacy and safety of peroxide-containing whitening strips and a paint-on gel relative to a non-peroxide experimental control.

METHODS

After informed consent, 52 healthy adults in Shanghai, China were randomized to one of three treatment groups: 6% hydrogen peroxide whitening strips (Crest Whitestrips), 5.9% hydrogen peroxide paint-on gel (Colgate Simply White), or water rinse which served as a negative experimental control. Strip use was twice daily over 7 days, while the paint-on gel and rinse were used twice daily over 14 days. Efficacy was measured from standard digital images of the maxillary anterior teeth, and safety was assessed from interview and intraoral examination.

RESULTS

Whitening strips provided the greatest end-of-treatment reduction in yellowness (Deltab*), with adjusted means +/- standard errors of -1.72 +/- 0.18 for the strip group, -0.48 +/- 0.10 for the paint-on gel group, and 0.13 +/- 0.09 for the water rinse group. For DeltaL* (lightness), end-of-treatment adjusted means +/- standard errors were 1.88 +/- 0.21 for the strip group, 0.60 +/- 0.15 for the paint-on gel, and -0.10 +/- 0.18 for the negative control. Groups differed significantly (P< 0.007) with respect to Deltab* and DeltaL* at end-of-treatment, as well as other color parameters. All treatments were well-tolerated.

Invasive cervical resorption: a case report

Invasive cervical resorption (ICR) is a relatively uncommon form of external resorption, which may occur in any tooth in the permanent dentition. Characterized by its cervical location and invasive nature, this resorptive process leads to progressive and usually destructive loss of the tooth structure, the clinical features of which often resemble internal resorption ("pink tooth"). This article describes a case report of ICR and its management. The salient features were a large resorptive defect and localized fibrous in-growth located almost wholly on the cervicolabial aspect of the maxillary incisor crown involving the enamel and dentin.

Efficacy and oral side effects of two highly concentrated tray-based bleaching systems

The aim of this study was to investigate the tooth-whitening efficacy and oral side effects of the two tray-based bleaching systems Visalys whitening (VW) and Opalescence PF (OP). A stratified, randomised distribution of the subjects (n = 60) to two treatment groups was performed according to baseline tooth brightness (L* values) as determined by colourimeter and to the criteria smoker/non-smoker. Tooth colour was evaluated by measuring L*a*b* values generated from standardised digital image analysis with Adobe Photoshop of the facial surfaces of the right central maxillary incisor. Tooth hypersensitivity, with intensity graded from 0 (no hypersensitivity) to 10 (high hypersensitivity), was assessed chair-side using an air syringe. After bleaching therapy, both treatment groups demonstrated significant improvements in tooth colour (p < or = 0.05). A shift towards less yellow (-Deltab*) and brighter (+DeltaL*) tooth colour was observed. Deltab* was significantly higher in the OP group in comparison to the VW group, DeltaL* showed no significant difference between the both treatment groups (p < or = 0.05). After bleaching, the intensity of tooth hypersensitivity was increased significantly compared to baseline in both groups (p < or = 0.05), with no significant difference between the both groups. Both highly concentrated bleaching systems are effective as tooth-whitening systems, with few reported side effects such as transient tooth hypersensitivity.

Clinical evaluation of the stain removal efficacy of a novel stannous fluoride and sodium hexametaphosphate dentifrice

PURPOSE

Recently, sodium hexametaphosphate has been introduced in dentifrice formulations to aid in the control of extrinsic stain. Two independent studies were conducted to evaluate the stain removal efficacy of a novel 0.454% stannous fluoride and sodium hexametaphosphate dentifrice (Crest Pro-Health) relative to a positive control whitening dentifrice (Colgate Total + Whitening) over a 2-week period in a subject population with pre-existing natural extrinsic stain.

METHODS

These studies were randomized, positive-controlled, parallel groups, double-blind, 2-week trials. Each study involved approximately 30 healthy adults with visible stain of the facial surfaces of the 12 anterior teeth. After baseline examination, subjects were randomly assigned to a treatment and instructed to brush unsupervised with the assigned dentifrice at least twice daily as they normally do. Efficacy was evaluated by modified Lobene examination on anterior teeth at baseline and end-of treatment (Week 2).

RESULTS

59 subjects, 29 in Study 1 and 30 in Study 2, were evaluable and included in the Week 2 analyses. Subjects ranged from 21-68 years of age. In each study, the positive control dentifrice statistically significantly (P < 0.0001) reduced stain scores following 2 weeks of brushing with median reductions of 61.9% and 94.4%. Similarly, the experimental 0.454% stannous fluoride and sodium hexametaphosphate dentifrice statistically significantly (P < 0.0001) reduced stain scores by 61.8% and 96.6% following 2 weeks of brushing. The adjusted mean changes between treatment groups did not differ significantly between the two dentifrice groups (P > 0.70 in each study). Both dentifrices were well tolerated. No subject discontinued treatment due to an adverse event.

Pink Teeth in a Series of Bodies Recovered From a Single Shipwreck

Pink teeth have most often been observed in victims of drowning but have also been reported in subjects who died suddenly and unnaturally. There is general agreement that there is no obvious connection between the occurrence of pink teeth and the cause of death, but the condition of the surroundings (especially humidity) must certainly play an important role in the development of the pink-tooth phenomenon. The frequency and distribution of postmortem pink coloration of the teeth have been studied among a representative sample of 52 cadavers. All the bodies were victims of a single shipwreck that occurred on March 13, 1997, in the middle of the Otranto Canal (Mediterranean Sea). The bodies were recovered from the seawater after approximately 7 months. A distinct pink coloration of the teeth was found in only 18 cadavers (13 females and 5 males) of ages ranging between 13 and 60 years. The phenomenon was more pronounced in younger individuals due to age-related changes of the root canal, less penetrable by the pigment responsible for the postmortem pink staining. By histochemical methods and autofluorescence, hemoglobin and its derivatives have been identified as the most likely pigments responsible for this postmortem process that can be considered analogous to postmortem lividity. These data are consistent with previous reports on pink teeth, indicating that the diffusion of the blood in the pulp into the dentinal tubules causes the red discoloration of the teeth. Based on the results, the pigmentation is more prominent on the teeth with single roots rather than in the posterior teeth with multiple roots.

Abnormal dentin structure in two novel gene mutations [COL1A1, Arg134Cys] and [ADAMTS2, Trp795-to-ter] causing rare type I collagen disorders

Histological and ultrastructural observations of dentin of two patients affected with rare types of type I collagen disorders are presented. In the first case, a homozygous nonsense mutation in ADAMTS2 (substitution of a codon for tryptophan by a stopcodon) causes type VIIC Ehlers-Danlos syndrome (EDS) with multiple tooth agenesis and focal dysplastic dentin defects. In the second case, a missense mutation in COL1A1 (substitution of arginine by cysteine) results in a type I EDS phenotype with clinically normal-appearing dentition. Tooth samples are investigated by using light microscopy (LM), transmission electron microscopy (TEM) and immunostaining for types I and III collagen, and tenascin. These are compared with samples from patients with types III and IV osteogenesis imperfecta (OI) in association with dentinogenesis imperfecta (DI), showing a consistently abnormal appearance of the dentin in all specimens, with variations being primarily those of degree of change. Similarities in histological changes include the alternating presence of normal and severe pathological areas in primary and secondary dentin, the latter being characterized by large canal-like structures in atubular areas. Ultrastructural evidence of pathological dentinogenesis include abnormal distribution, size and organization of collagen fibers, which may also be found in clinically unaffected teeth. The histological and ultrastructural changes seen can be explained on the basis of odontoblast dysfunction which may be secondary to the collagen defect, interfering with different levels of odontoblast cell function and intercellular communication. These observations on (ultra)structural dentin defects associated with the two novel gene mutations are the first ever reported.

Microbiological assessment of occlusal brown-spot lesions in primary molars

Conventional cultural methods were used to compare the plaque flora and the level of infection of the dentine underlying 51 occlusal brown-spot lesions and 21 sound occlusal sites on the primary dentition. Freshly extracted primary molar teeth were used, and occlusal brown-spot lesions and sound occlusal sites were identified using laser fluorescence (LF) and clinical visual methods. A standardized plaque sample was taken from each site, and an LF score was recorded for one discrete site per tooth. The teeth were carefully opened at each predetermined site to determine the clinical status of the underlying dentine, and samples were collected using a sterile bur. The microbiota of the plaque and dentine samples were enumerated and identified. The mean LF scores for the sound sites and brown-spot lesions were 1.2 and 30.5 (p < 0.001), and all the sound sites exhibited hard sound dentine, but 6 out of 51 brown spots exhibited softened dentine. Overall there was no significant (p > 0.1) difference between the level of infection of the dentine of the sound and brown-spot sites, although some sites in the brown-spot lesions yielded high numbers of bacteria. However, the numbers of bacteria as log10(CFU per sample + 1) +/- SE recovered from the plaque above the brown-spot lesions were significantly greater than above the sound sites, i.e. 2.89 +/- 0.24 and 0.89 +/- 0.33, respectively. These data indicate that brown-spot lesions may be more plaque retentive than sound sites and that they are either arrested or arresting lesions, which may require preventive intervention.

Clinical trial evaluating two peroxide whitening strips used by teenagers

Double-blind clinical research was conducted to compare the clinical response of a thin, concentrated peroxide whitening strip (relative to a marketed control) among a teenage population with preceding safety and efficacy data. Informed consent and child assent was obtained from 48 teens, 13-17 years of age. After baseline measurements were taken, subjects were divded randomly into two groups, one using a thin 10% hydrogen peroxide whitening strip, the other using a 6.5% hydrogen peroxide strip with a thicker gel layer. Strip use was 30 minutes twice per day for 22 days on the maxillary arch, followed by 22 days on the mandibular arch. Efficacy was measured objectively based on L*a*b* color change from digital images taken every 11 days, where L* indicates lightness and b* indicates blue-to-yellow shade. The mean age was 15.1 (+/-1.5) years. Relative to baseline, both strip groups experienced significant (p < 0.0001) color improvement for yellowness (deltab*) and lightness/brightness (deltaL*) beginning at the first visit (Day 11). Continued use resulted in significant color improvement through Day 22. Groups did not differ significantly (p > 0.33) with respect to combined deltab* or deltaL* at end-of-treatment. Tooth sensitivity and oral irritation represented the most common adverse events. No subject discontinued early due to a treatment-related adverse event. Teenagers who used either 10% hydrogen peroxide gel or 6.5% hydrogen peroxide gel whitening strips twice a day for 44 days saw significant tooth whitening without serious adverse events.

[Improvement of aesthetics by porcelain laminate veneers]

PATIENT

The patient consulted our department with a chief complaint of aesthetic problems due to anterior tooth discoloration. Since improvement by bleaching was considered impossible, porcelain laminate veneer restorations were performed.

DISCUSSION

Insertion took too long for the patient's satisfaction due to the repetition of color adjustment and recontouring. The veneer preparation area should be limited to enamel; however when dentin is exposed, it is important to treat with primer before adhesion.

CONCLUSION

In this case, establishing a selection criterion for bleaching, a combined approach was also considered. Although the preparation area is limited to enamel, phosphoric acid etching should be avoided when dentin is exposed. The treatment process should be arranged so as to reduce the manipulation period.

Comparative Fluorescence Spectroscopy Shows Differences in Noncavitated Enamel Lesions

The aim of this study was to compare emission spectra from noncavitated enamel caries with different degrees of discoloration under a wide range of excitation wavelengths. Freshly extracted human molars with white spot, light discolored and dark discolored brown spot enamel caries were selected (n = 4 each). Rectangular blocks (3.5 x 3.5 mm) were cut from the carious area and a corresponding sound area of the same tooth. Emission spectra were recorded from carious and the corresponding sound areas using a fluorescence spectrophotometer at excitation wavelengths from 360 nm up to 580 nm in steps of 20 nm. The specimens were submerged in water during measurement. The spectra were corrected and normalized to peak intensity for comparisons between spectra from sound and carious areas of each tooth. Excitation spectra were recorded for selected emission wavelengths that showed maximum intensity. Emission spectra of all types of carious lesions were shifted towards longer wavelengths (red shift) when compared to the spectra of the corresponding sound enamel. The red shift was highest for dark brown spot lesions and lowest for white spot lesions (p <or= 0.001). Distinct fluorescence bands within 600-700 nm typical for porphyrin compounds were strongest for excitation wavelengths from 400 to 420 nm and present in most of the lesions investigated.

A six-month study of two self-applied tooth whitening products containing carbamide peroxide

Bleaching offers a non-interventive way of improving the appearance of sound, yet discolored anterior teeth. Until recently, the whitening agent was applied using a tray, but now other methods of delivering whitening agents, such as those using brush applicators, are available. This study investigated the tooth whitening efficacy of two novel, self-applied tooth whitening systems containing either 18% (Group 1) or 16.4% (Group 2) carbamide peroxide. Ninety-five subjects, ranging in age from 18 to 70 with anterior teeth A3 or darker, were recruited and randomly allocated to a group. The subjects were instructed to apply the formulation to all maxillary anterior teeth after brushing in the morning and evening. At baseline, two weeks and six months the upper six anterior teeth of the subjects were measured using the Vita shade guide tab system. In addition, the gingival health of the labial surfaces of the upper six anterior teeth was assessed using the Loee and Silness Gingival index (Loee & Silness, 1963) at baseline and at two weeks. The mean (SD) reduction in shade guide scores was 4.1 (2.4) shade guide tabs for subjects in Group 1, compared to 3.7 (2.6) shades for those in Group 2. This difference was not statistically significant (p=0.5). During the course of study, the gingivitis scores reduced from a mean (SD) of 0.91 (0.62) at baseline to 0.44 (0.55) at final examination (48% reduction). At the six-month recall, the mean (SD) reduction in shade guide scores was 2.3 (2.7) shade guide tabs for subjects in Group 1, compared to 2.5 (2.5) shades for those in Group 2. The different concentrations tested were found to be equally effective in improving the whiteness of upper anterior teeth by approximately four shades over a two-week period and the majority of the whitening benefit (c.60%) was sustained at six-month recall.

Effect of toothpaste with natural calcium carbonate/perlite on extrinsic tooth stain

OBJECTIVE

The current study was designed to determine the effect of natural calcium carbonate toothpaste containing Perlite and microgranules (Whitening toothpaste) on extrinsic tooth stain compared to a standard commercial toothpaste formulation with precipitated calcium carbonate (PCC) as abrasive and a commercial toothpaste with dicalcium phosphate dihydrate (DCPD) as abrasive.

METHODS

The toothpastes were evaluated in a double blind, three-cell, stratified (tobacco use; baseline tooth stain level), parallel group design study involving 600 subjects with extrinsic tooth stain. Subjects brushed twice daily with their allocated toothpaste for four weeks. Extrinsic tooth stain was measured using the Macpherson modification of the Lobene stain index.

RESULTS

ANCOVA showed significant differences between toothpastes (p=0.037). Subsequent multiple comparisons using pairwise t-tests, showed the Whitening toothpaste to be superior to the DCPD toothpaste (p=0.014) and the PCC toothpaste (p=0.067). When a Box-Cox transformation was made to the data (y0.6) to improve normality, these two differences were more accurately estimated at p=0.004 and p=0.03 respectively.

CONCLUSION

The Whitening toothpaste has been shown to be significantly more effective in tooth stain removal than the two standard commercial toothpaste formulations.

Tetracycline and other tetracycline-derivative staining of the teeth and oral cavity

Tetracyclines (TCN) were introduced in 1948 as broad-spectrum antibiotics that may be used in the treatment of many common infections in children and adults. One of the side-effects of tetracyclines is incorporation into tissues that are calcifying at the time of their administration. They have the ability to chelate calcium ions and to be incorporated into teeth, cartilage and bone, resulting in discoloration of both the primary and permanent dentitions. This permanent discoloration varies from yellow or gray to brown depending on the dose or the type of the drug received in relation to body weight. Minocycline hydrochloride, a semisynthetic derivative of tetracycline often used for the treatment of acne, has been shown to cause pigmentation of a variety of tissues including skin, thyroid, nails, sclera, teeth, conjunctiva and bone. Adult-onset tooth discoloration following long-term ingestion of tetracycline and minocycline has also been reported. The remarkable side-effect of minocycline on the oral cavity is the singular occurrence of "black bones", "black or green roots" and blue-gray to gray hue darkening of the crowns of permanent teeth. The prevalence of tetracycline and minocycline staining is 3-6%. The mechanism of minocycline staining is still unknown. Most of the reviewed literature consisted of case reports; longitudinal clinical trials are necessary to provide more information on the prevalence, severity, etiology and clinical presentation of tetracycline and TCN-derivative staining in the adult population.

Prevalence of self-assessed tooth discolouration in the United Kingdom

AIMS

To determine the prevalence of perceived tooth discolouration in the United Kingdom and to investigate socio-demographic variations and satisfaction with own tooth colour.

METHODS

A national cross-sectional questionnaire study was carried out using a multistage random probability sample. Assessment of people's perceptions of their own tooth colour was conducted by asking study participants to match colour to the closest of a set of photocards demonstrating different levels of tooth discolouration. A separate question asked how satisfied they were with their tooth colour. Information on socio-demographic characteristics of the population were gathered at the same time.

ANALYSIS

Data was coded and entered into SPSS software. Descriptive statistics were used to determine the prevalence of perceived discolouration and satisfaction with own tooth colour. Bivariate and regression analyses were performed to explore the effect of socio-demographic variations.

RESULTS

The self-assessment exercise was completed for 3215 subjects. Half of the study population perceived their tooth colour to be normal and 6% perceived that they had severe discolouration, the remainder reported themselves to have levels of tooth discolouration between these two extremes. Satisfaction with tooth colour decreased with increased discolouration. Sex, age, income and smoking, had statistically significant effects on the prevalence of perceived discolouration (P< 0.01).

CONCLUSIONS

Half of the people in this study perceived themselves to have tooth discolouration. Results suggest that the general public is concerned about dental appearance in terms of tooth colour, indicated by public dissatisfaction with relatively mildly discoloured teeth. Findings may suggest that a further increase in the demand of tooth whitening services and cosmetic dentistry in general is likely. The changing emphasis and level of perceived dissatisfaction need to be taken into account in planning dental services. Evidence based approaches are needed for the appropriate management of patients who demand treatment of mild discolouration.

A chewing gum containing 7.5% sodium hexametaphosphate inhibits stain deposition compared with a placebo chewing gum

The 2-period, randomized, double-blind, placebo-controlled, crossover study compared the stain-prevention and stain-removal benefit of a chewing gum containing 7.5% sodium hexametaphosphate (measured by digital image analysis) with a placebo chewing gum. The results of this study support that sodium hexametaphosphate delivered from a chewing gum prevents dental stain formation and facilitates stain removal, which leads to a perceptible whitening benefit. The long-term clinical benefits of sodium hexametaphosphate delivered from chewing gum have not been reported in the literature.

Effects of the hydroxyl radical and hydrogen peroxide on tooth bleaching

The mechanisms of bleaching of discolored coronal teeth using hydrogen peroxide (H2O2) were investigated. In a scanning-electron-microscopy study, the intertubular dentin and peritubular dentin were dissolved by high concentrations of H2O2, which is used for bleaching. The X-ray diffraction study showed that hydroxyapatite was not influenced by H2O2. In an electron-spin-resonance study, more hydroxyl radical (* OH) was detected as the H2O2 concentration was increased. When amino acids that are core components of dentin proteins, such as proline and alanine, were added to H2O2, the generation of * OH decreased, but there was no change when glycine was added. A nuclear-magnetic-resonance study showed that proline was degraded completely by H2O2, the structure of alanine changed slightly, and glycine was not affected by H2O2. It is suggested that H2O2 and * OH do not influence the inorganic tissue of dentin but attack the organic component of dentin. These facts suggest that * OH has the main role in tooth bleaching with H2O2.

Tooth colour: a review of the literature

OBJECTIVES

To review current knowledge with respect to tooth colour and its measurement.

METHODS

'Medline' database for the period 1966 to the present day and 'ISI Web of Science' database for the period 1974 to the present day were searched electronically with key words tooth, teeth, colour and color.

CONCLUSIONS

The colour and appearance of teeth is a complex phenomenon, with many factors such as lighting conditions, translucency, opacity, light scattering, gloss and the human eye and brain influencing the overall perception of tooth colour. The measurement of tooth colour is possible via a number of methods including visual assessment with shade guides, spectrophotometry, colourimetry and computer analysis of digital images. These methods have successfully been used to measure longitudinal tooth colour changes when the dentition has undergone tooth whitening procedures.

Clinical studies on the appearance of natural anterior teeth in young and old adults

OBJECTIVES

To evaluate the typical appearance of natural anterior teeth in young and elderly people and to develop guidelines for the natural appearance of dentures.

DESIGN

Clinical examination and photography. Inclusion criteria were a dental state with natural anterior teeth and no more than two crowns.

SUBJECTS

A study group (SG) consisting of 64 patients ranging in age from 60 to 86 years (67.3 +/- 5.8) and a control group (CG) composed of 64 dental students aged 21-33 years (25.8 +/- 2.4).

SETTING

Dental schools of the Johannes-Gutenberg-University Mainz and the University of Leipzig.

RESULTS

Most participants were content with the appearance of their own natural teeth. With relaxed lips a mean of 1.5 (+/-0.19) mm of upper incisors and 1.6 (+/-0.19) mm of lower incisors were visible in the SG compared with 2.5 (+/-0.16) and 0.4 (+/-0.07) mm in the CG, respectively. The subjects in the SG showed a greater diversity in position of teeth in the anterior arch and this was more often with incisors than with canines. Features such as stains, cracks and defects were much more noticeable in the SG. An inter-dental 'black triangle' seemed to be a typical feature of an aged dental appearance.

CONCLUSION

The majority of people older than 60 years who still have their own natural anterior teeth would not wish for a change in appearance if they needed a prosthodontic reconstruction. Thus techniques for customisation should be promoted to obtain a natural appearance in dentures.

Placebo-controlled clinical trial evaluating a 10% hydrogen peroxide whitening strip

OBJECTIVE

A placebo-controlled clinical trial was conducted to evaluate the effectiveness and safety of a 10% hydrogen peroxide strip-based whitening system in subjects with tooth discoloration and no previous history of tooth whitening.

METHODOLOGY

Informed consent was obtained, and 39 healthy adults were randomly assigned to either 10% hydrogen peroxide whitening strips (Crest Whitestrips Premium) or placebo strips with no peroxide. Strips were used unsupervised twice daily for 30 minutes over a seven-day period. At day four and day eight, tooth color (L*a*b*) was measured on the maxillary anterior teeth from standard digital images, and safety was assessed from examinations and subject reports.

RESULTS

After three treatment days, the 10% hydrogen peroxide strip group had significant (p < 0.0001) color improvement from baseline, with means (SD) for deltab* and deltaL* of -1.57 (0.472) and 1.72 (0.619), respectively. Continued strip use from day four to day eight resulted in significant (p < 0.002) incremental improvement in both yellowness and lightness. By the end of treatment (day eight), the adjusted mean (SE) color change between groups was -2.20 (0.275) for deltab* and 2.24 (0.254) for deltaL*, a highly significant (p < 0.0001) color improvement for the 10% hydrogen peroxide group relative to placebo, of similar absolute magnitude for deltab* and deltaL*. Treatment with the 10% hydrogen peroxide strips was well-tolerated, with tooth sensitivity and oral irritation representing the most common findings.

CONCLUSION

In this double-blind, placebo-controlled clinical trial, statistically significant tooth whitening was evident after three days' treatment with 10% hydrogen peroxide whitening strips, and color improved with continued usage over seven days.

Correlation between fissure discoloration, Diagnodent measurements, and caries depth: an in vitro study

PURPOSE

This in vitro study was performed to correlate the presence of discoloration on occlusal surfaces with its histological depth and assess its influence on Diagnodent measurements in a group of permanent and primary teeth.

METHODS

Ninty-five primary and 95 permanent third molars were randomly selected from a pool of macroscopically intact teeth. One site of the fissure on each occlusal surface was selected and categorized according to its discoloration. Each site was measured 3 times with Diagnodent. The teeth were prepared histologically and evaluated according to their caries extent under a microscope (final magnification x 12.8).

RESULTS

In the group of permanent teeth with dark brown or black discoloration (N=23), 13% showed dentinal caries, 57% were sound or had an initial enamel lesion, and 30% had a deep enamel lesion. In the group of primary teeth with dark brown and black discoloration (N=19), 42% presented dentinal caries, 42% showed deep enamel caries, and 16% had an initial enamel lesion. The difference between permanent and primary teeth was statistically significant (P<.05). Discolored fissures showed higher Diagnodent values than nondiscolored or opaque fissures in both groups (independent of their caries status).

CONCLUSIONS

The presence of brown or dark spots on fissures were not useful for the prediction of dentinal caries for permanent teeth. In primary teeth, however, a higher correlation between fissure discoloration and dentinal lesions was found. Diagnodent tends to overscore discolored surfaces.

Results after two years of non-operative treatment of occlusal surface in children with high caries prevalence

The aim of this study was to describe the 2-year results of an individualized treatment program designed to control occlusal caries in erupting first permanent molars. The sample consisted of 145 five-to-six-year-old students divided into a control group (n = 71) and a test group (n = 74). All test children received a biannual basic preventive program and a recall system according to individual disease activity. The basic program consisted of 3 (March) and 2 (August) sessions of oral hygiene orientation and toothbrushing with fluoride gel. The analysis of the baseline and 1-2-year data showed a significant reduction in the number of active lesions in the test group. In the control group, there were initially 70 active lesions and after two years 68 surfaces remained with disease and 24 surfaces had been filled. The children in the test group had 80 surfaces with active lesions initially and after two years only 3 surfaces with disease remained. From the 15 cavitated lesions, only 5 surfaces needed to be filled. This program showed that care of erupting teeth on an individualized basis can control occlusal caries.