Vertical shoulder preparation design for porcelain laminate veneer restorations

The clinical success of porcelain laminate veneers depends on numerous factors that include the framework of the dental and gingival structures and their ability to withstand masticatory forces. In order to ensure aesthetic harmony, the clinician must reproduce numerous anatomical components (e.g., cementoenamel junction, points of concavity, developmental lobes, line angles, incisal edge survey form) in restorations while simultaneously providing sufficient functional integrity. This article demonstrates the vertical shoulder preparation design, which enhances the aesthetics and stabilization factors of porcelain laminate veneer restorations.

Combined professional and home care nightguard bleaching of tetracycline-stained teeth

The effectiveness of combining in-office and at-home nightguard vital bleaching on tetracycline-stained teeth was evaluated. Grade 1 and grade 2 tetracycline stains were eliminated completely in two months by this combination approach. Grade 3 stains, the most severe, were lightened significantly with a reduction in the banding effect. The most common side effect was an increase in tooth sensitivity, especially to cold, while actively in treatment. All patients reported disappearance of the sensitivity after termination of the treatment phase.

The efficacy of reservoirs in bleaching trays

Thirty patients were selected to bleach their maxillary teeth. Vacuum-formed trays were fabricated for the maxillary arch so that only one quadrant of bleaching tray had reservoirs. Nupro Gold 10% carbamide peroxide gel was given to patients. They were instructed to place a drop of gel in each tooth area and wear the trays twice a day for two-hour periods. After 10 days the patients were evaluated for shade changes in each quadrant. No clinical difference was observed in the after-shade match of the two quadrants. It appears that the addition of blockout spacers to create reservoirs does not increase the success of home bleaching.

Comparison of 10% carbamide peroxide and sodium perborate for intracoronal bleaching

The purpose of this study was to compare 10% carbamide peroxide to the combination of sodium perborate and water as intracoronal bleaching agents. Forty-four extracted teeth were discolored in vitro. Bleaching agents were placed intracoronally to the level of the cemento-enamel junction for 12 days; solutions were replaced after four and eight days. Standardized slides were used to rank color changes; a colorimeter was used to quantify color change. After 12 days, 65% of the discolored teeth in the 10% carbamide peroxide group and 67% of the discolored teeth in the sodium perborate group had lightened to their original shade or lighter. While there was no statistical difference between the two treatments, sodium perborate was easier to use.

Clinical evaluation of bleaching agents of different concentrations

OBJECTIVE

The purpose of this study was to evaluate the degree of color change, any rebound effect, and sensitivities associated with using 2 different concentrations of carbamide peroxide in vivo.

METHOD AND MATERIALS

Twenty-five subjects used 10% and 15% agents in trays for 14 days on different sides of their maxillary arches. Subjects returned in 3 days and at 1, 2, 3, and 6 weeks for evaluation of color change and rebound effect. Shade matching, photographic means, and a colorimeter were used for evaluation. Subjects self-reported gingival and tooth sensitivity on a scale of 1 (no sensitivity) to 5 (severe sensitivity).

RESULTS

After 2 weeks, delta L*, delta a*, delta b*, delta E* and delta shade guide rank means for the 10% whitening agent were 6.50, -1.37, -4.63, 8.79, and -15.40, respectively; for the 15% agent, they were 8.72, -1.63, -5.90, 11.03, and -16.59, respectively. After 6 weeks, delta L*, delta a*, delta b*, delta E*, and delta shade guide rank means for the 10% whitening agent were 3.04, -0.99, -3.19, 5.13, and -13.13, respectively; for the 15% agent, they were 3.48, -1.01, -3.60, 5.58, and -13.65, respectively. Means for gingival sensitivity were 1.18 and 1.21 for the 10% and 15% agents, respectively; means for tooth sensitivity were 1.21 and 1.26 for the 10% and 15% agents, respectively.

CONCLUSION

All 3 methods of evaluation revealed a significant difference in the tooth lightness achieved by 10% and 15% products at 2 weeks but no significant difference at 6 weeks. No statistically significant difference was found in gingival or tooth sensitivity.

Enamel microabrasion

A significant number of patients complain of discoloured teeth. The enamel microabrasion technique described in this article is a simple conservative method for improving the appearance of discoloured enamel.

A comparison of the Braun Oral-B 3D plaque remover and the Sonicare plus electric toothbrush in removing naturally occurring extrinsic staining

PURPOSE

To compare the extrinsic stain-removing properties and the safety of the Braun Oral-B 3D Plaque Remover and the Sonicare Plus electric toothbrush.

MATERIALS AND METHODS

This randomized, parallel group, investigator-blinded study involved 67 subjects and was conducted over 6 weeks. After recruitment, the subjects received a baseline stain assessment (Lobene stain index) and a soft and hard tissue examination, and were then randomized to use either the Sonicare or the 3D device. All subjects were trained to use both devices, and instructed to brush twice daily with their assigned device for 2 min. The subjects' brushing technique was checked after 2 weeks. After a further 4 weeks, the subjects underwent a final stain assessment and soft and hard tissue examination. A questionnaire was also completed.

RESULTS

At 6 weeks, oral hard and soft tissue examinations revealed no abrasion or damage in either group. Both brushes produced significant (P < 0.001) reductions from baseline in total stain score, stain area and intensity, but group comparisons showed that these reductions were significantly (P < 0.001) greater for the 3D device.

Enamel color change by microabrasion and resin-based composite

A simple technique using microabrasion with hydrochloric acid/pumice and resin-based composite to improve the esthetics of discolored anterior teeth is described.

Use of a whitening dentifrice for control of chlorhexidine stain

A major drawback to clinicians prescribing and patients using chlorhexidine rinse is the development of extrinsic staining. In order to assess the effectiveness of a whitening dentifrice in controlling chlorhexidine stain, fifty-seven subjects rinsed with chlorhexidine twice daily while brushing twice daily with either fluoridated whitening or a fluoridated regular dentifrice. Stain was assessed at 1, 2, and 3 month intervals using a stain index with two components; one with parameters for color intensity and one for tooth percentage covered with stain. Facial surfaces accumulated less stain than lingual surfaces. For many, although not all surfaces, and at many, although not all time periods, the group utilizing the whitening dentifrice exhibited less staining. It is advantageous to recommend a whitening dentifrice that has demonstrated stain suppression when prescribing a chlorhexidine rinse. Improved patient satisfaction leading to increased compliance with the antimicrobial regimen is a desired outcome.

Nightguard vital bleaching beneath existing porcelain veneers: a case report

Dentist-prescribed, at-home bleaching with 10% carbamide peroxide was used to lighten the apparent color of teeth with preexisting porcelain veneers. Veneers had been placed over unprepared, tetracycline-stained teeth; the translucency of the veneers over the discolored teeth resulted in a graying of the veneers. A custom-fitted tray with no reservoirs and no gingival scalloping was fabricated. A 10% carbamide peroxide material was applied nightly for 9 months to achieve the maximum change in the underlying tooth color. The patient was pleased with the apparent color change. Tooth sensitivity during treatment was minimal (lasting 4 days total); the patient treated sensitivity by brushing with a potassium nitrate-containing toothpaste or applying fluoride in the tray.

Preliminary report: laboratory-induced stain removal as assessed by environmental scanning electron microscopy

Environmental scanning electron microscopy (ESEM) was employed to observe stain removal during brushing with Arm & Hammer Dental Care and Crest Regular Toothpaste. ESEM allows serial examinations of the same sample, and does not require a destructive preparative process. Three extracted molars were cleaned, placed into a 96-hour broth culture of Streptococcus mutans, and stain was produced with undiluted chlorhexidine rinse, concentrated coffee and tea for a period of 23 days. After staining, the teeth were examined by ESEM, then brushed using a toothbrushing machine. Imaging was repeated after 5, 10, 15 and 30 seconds of brushing. As seen with ESEM, the Arm & Hammer product had different effects than those from the distilled water control, suggesting something other than that expected from abrasive and mechanical forces alone. There were also differences from the Crest dentifrice removal on this single sample, suggesting a possible difference between the two products. Further studies are needed to confirm and explain these effects.

[The efficacy on natural extrinsic stain of Colgate whitening dentifrice--eight-week study]

OBJECTIVE

To assess the effect on natural extrinsic dental stain by use of a dentifrice containing 1% tetrasodium polyphosphate (TSPP), 7% sodium tripolyphosphate (STPP), 0.243% sodium fluoride and 10% high cleaning silica (HCS) over an eight-week period was compared to a sodium fluoride/silica placebo dentifrice without stain removal ingredients.

METHODS

Ninety one subjects were selected and stratified into two balanced groups randomly assigned to use the test dentifrice or the placebo dentifrice. The two groups were well balanced with regard to their mean baseline stain index scores, gender and tobacco habits. Subjects were instructed to brush their teeth twice daily (morning and evening) for one minute with their assigned dentifrice and a commercially available soft bristled toothbrush. Extrinsic dental stain examinations, which included mean stain area and mean stain intensity, were conducted at baseline, four and eight weeks. The same dental examiner conducted examinations on the subjects at each examination.

RESULTS

After eight-week use of their assigned products, those subjects in the TSPP/STPP/HCS dentifrice group demonstrated a statistically significant (P = 0.0001) stain reduction of 37.1%, as compared to the fluoride placebo dentifrice group without stain removal ingredients.

CONCLUSION

The use of a dentifrice containing 1% tetrasodium polyphosphate, 7% sodium tripolyphosphate, 0.243% sodium fluoride and 10% high cleaning silica is effective in reducing natural extrinsic dental stain, when compared to a placebo fluoride dentifrice.

The role of cosmetic dentistry in restoring a youthful appearance

BACKGROUND

Dentistry is faced with a population that is getting older and keeping more of its natural teeth. Smiles show physical and esthetic signs of aging. Advances in the area of cosmetic dentistry now offer the dental profession new opportunities in conservative and esthetic restorative procedures that have the potential to reverse the signs of dental aging, thereby making patients appear younger.

CASE DESCRIPTION

The physical and esthetic attributes of an aged dentition are identifiable. Tooth wear over time alters the appearance of the teeth and smile in a way that is perceptible to dentists and laypeople. Bonding and adhesive ceramic restorative procedures have the potential of reversing the esthetic manifestations of the aging process for teeth. Specific diagnostic tools, including a composite resin mock-up and construction of an incisal putty matrix, allow for previsualization of possible treatment outcomes and allow clinicians to resolve occlusal as well as esthetic treatment concerns before initiating actual treatment.

CLINICAL IMPLICATIONS

The ability to make patients look younger through cosmetic enhancement of teeth and smiles has tremendous implications for the future practice of dentistry. Dentists who have the training and skills to meet the increasing demand for esthetic procedures by patients seeking to restore a youthful appearance may find an expanded role within their practices for this type of treatment.

Efficacy of two dentifrices on removal of natural extrinsic stain

PURPOSE

To evaluate the 6-week effect on natural extrinsic dental stain from the use of a dentifrice containing 10% aluminum oxide, 1500 ppm sodium monofluorophosphate in a precipitated calcium carbonate (PCC) base or a second dentifrice containing 0.5% calcium peroxide (CP), 1500 ppm sodium monofluorophosphate in a PCC base compared to a fluoride placebo dentifrice without stain removal ingredients.

MATERIALS AND METHODS

A total of 94 subjects were entered in the study, and stratified into three balanced groups according to their baseline mean Lobene Stain Index scores. The three groups were randomly assigned to use one of the two test dentifrices or the placebo dentifrice. The three groups were well balanced with regard to their mean baseline stain index scores, gender and tobacco habits. Subjects were instructed to brush their teeth twice daily (morning and evening) for 1 minute with their assigned dentifrice and a commercially available soft bristled toothbrush. Extrinsic dental stain examinations, which included mean stain area and mean stain intensity, were conducted at baseline and 6 weeks. Examinations were conducted by the same dental examiner (F.A.) on the subjects at each examination.

RESULTS

After 6 weeks' use of their assigned products, those subjects in the aluminum oxide/PCC dentifrice group and those subjects in the CP/PCC dentifrice group demonstrated statistically significant improvements, as compared to the fluoride placebo dentifrice group without stain removal ingredients.

Minocycline-induced staining of the adult permanent dentition: a review of the literature and report of a case

Tetracycline staining of teeth during tooth development is well documented. We report here the rarer condition of tetracycline staining of adult teeth. This occurrence appears to involve enamel surface demineralization/remineralization and can produce staining clinically indistinguishable from that occurring during tooth development.

Carbamide peroxide whitening of nonvital single discolored teeth: case reports

Patients who present with a single discolored tooth represent a significant restorative challenge. These case reports describe an economic and conservative treatment option for these patients. The situations presented demonstrate techniques for bleaching with carbamide peroxide in a traditional nightguard or with an inside-outside technique to achieve acceptable esthetic results on isolated nonvital discolored teeth. Although these techniques may not be effective in all cases, they do not compromise or eliminate any future treatment options.

Porcelain veneers: a challenging case

A patient in his early 20s with teeth badly discoloured by tetracycline was seeking treatment to improve his esthetics. Because retreatment and cost were important considerations, porcelain veneers were the treatment of choice. The challenge in this case was to mask the underlying tetracycline stain before the final cementation and thus gain more control over the final shade of the veneers.

Porcelain for veneers

An ideal porcelain veneer placed on a non-discolored tooth requires the least amount of tooth preparation and the use of a translucent porcelain that interferes minimally with the transmission of light. In contrast, veneering a discolored tooth requires additional tooth preparation and the use of a chromatic or opacious porcelain. This article discusses several criteria for the selection of porcelain for porcelain veneers, including some steps to enhance the esthetic properties of these restorations.

In vitro tooth whitening by a sodium bicarbonate/peroxide dentifrice

The main purpose of this laboratory study was to determine the tooth whitening effect of a baking soda dentifrice containing stabilized 1% hydrogen peroxide following repeated applications to intrinsically stained teeth. Additional objectives were to investigate (1) the influence of tooth surface curvature and moisture on color measurements, (2) preliminary treatment parameters using 1% hydrogen peroxide solution, and (3) the relationship between Vita shade guide standards and instrumental color readings. Human tooth specimens with intrinsic stain were specially prepared and measured for color (L*a*b*) by means of diffuse reflectance spectrophotometry. Specimens were measured under wet and dry conditions with natural and flattened enamel surfaces. A preliminary test was conducted with 1% H2O2 solution to establish tooth whitening versus treatment time. Then, new tooth specimens were treated repeatedly with slurries of silica, baking soda, or baking soda/peroxide dentifrices at 30-minute intervals, and color measurements were taken under both wet and dry conditions after 4, 8, 16 and 24 hours. L*a*b* color measurements of the Vita shade guide teeth were also made in order to relate laboratory color changes to clinical effects. The parameter testing results showed that flattening the enamel surface had no effect on tooth color, but the teeth rapidly became lighter and less yellow upon air-drying. The 1% H2O2 solution caused both a significant decrease in yellow (b*) and an increase in lightness (L*). Since the reduction for b* occurred more rapidly and to a greater extent than the L* factor, the b* component may be the more important indicator of tooth whitening by bleaching. Compared to the silica and baking soda dentifrices, the baking soda/peroxide dentifrice significantly decreased the yellow color (b*) of the teeth after 8 or more hours of topical treatment. The instrumental color readings of the Vita Shade guide teeth showed that the color differences between the standards were not linear or consistent, and their accuracy for assessing clinical changes in tooth whiteness is questionable.