Prevention efficacy of dentin tubule sealing with Nd:YAG laser against tooth discoloration induced by vital pulp treatment

BACKGROUND

The discoloration potential of dental materials and applications such as vital pulp therapy also cause discoloration due to the presence of blood. Dentin tubule sealing methods could be used for the prevention of discoloration.

AIM

The purpose of this study was to evaluate the effect of sealing pulp chamber walls with Nd:YAG laser against discoloration caused by tricalcium silicate-based materials in the presence and absence of blood contamination.

DESIGN

Eighty-one extracted human maxillary incisors were prepared and randomly divided into nine groups according to the Nd:YAG laser application, the cement to be used (NeoMTA Plus/Biodentine), and the presence or absence of blood. The color measurements were obtained with a spectrophotometer at baseline and then at the sixth (T1) and 12th (T2) months thereafter.

RESULTS

Sealing with Nd:YAG laser and placing NeoMTA Plus or Biodentine on human blood significantly increased discoloration at T1 and T2 (p < .05). Similarly, without sealing the cavity and placing NeoMTA Plus or Biodentine on human blood significantly increased discoloration at T1 and T2 (p < .05).

CONCLUSION

Regardless of sealing the dentin tubules with Nd:YAG laser, NeoMTA Plus and Biodentine caused more discoloration in the presence of blood contamination.

Coffee-stained tooth enamel color restoration and surface abrasion with whitening and regular toothpaste

PURPOSE

To evaluate the effectiveness of whitening toothpaste in restoring tooth color after coffee staining and its potential impact on enamel surfaces compared with regular toothpaste.

METHODS

Bovine tooth enamel specimens were prepared and stained with coffee solutions before undergoing brushing simulation with different toothpaste slurries (whitening, regular, reference). For precise evaluation, spectrophotometric measurements were taken at intervals to assess color changes using the CIELAB (Commission Internationale de l'Éclairage Lab*) color space. Additionally, profilometric measurements were taken to determine the impact of toothpaste type on the roughness and abraded depth of the enamel surface. To understand the effects of toothpaste and brushing on color change, surface roughness, and abraded depth, while also considering correlations between these factors, the findings were analyzed using mixed-effects models.

RESULTS

The whitening toothpaste group demonstrated the highest recovery rate (71%) after 10,000 brushstrokes, followed by the regular toothpaste group (48%) and the reference slurry group (43%). The mixed-effects model analysis revealed that the reference group had a smaller change in lightness (ΔL) than those in the regular toothpaste group. The whitening toothpaste group showed a greater change in lightness on average than those in the regular toothpaste group, with an increase in lightness as the number of brushstrokes increased. According to the roughness and abraded depth data, the whitening toothpaste group was least affected by brushing, while the reference and regular toothpaste groups showed higher levels of roughness and abraded depth at all intervals.

CLINICAL SIGNIFICANCE

Gaining a thorough understanding of the effectiveness of whitening toothpaste and its impact on the enamel surface plays a crucial role in refining toothpaste formulations and advancing tooth whitening techniques in dental care.

Evaluation of the effectiveness of different treatment approaches in preventing coronal discoloration caused by regenerative endodontic treatment

OBJECTIVES

This study aimed to evaluate the effectiveness of Teethmate desensitizer, a dentin bonding agent (DBA), Nd:YAG laser, and Er:YAG laser, which provides dentin tubule occlusion in the pulp chamber with different mechanisms, in preventing tooth discoloration due to regenerative endodontic treatment.

MATERIALS AND METHODS

One hundred five extracted maxillary human incisors with single roots and single canals were included in the study. The apical third of each tooth was resected below the enamel-cementum junction (CEJ) to obtain a standard root length as 10 ± 1 mm. Root canal preparation was performed using the ProTaper Next files up to X5. Root canals were prepared with Gates Glidden (# 2-4) burs to simulate the immature root apex and an apical diameter of 1.1 ± 0.1 mm was obtained. The teeth were randomly divided into 7 groups (n = 15): DBA, Teethmate, Nd:YAG, Er:YAG, Biodentine, Blood, and Negative Control. Relevant dentin tubule occlusion methods were applied to DBA, Teethmate, Nd:YAG, and Er:YAG groups. Following dentin tubule occlusion procedures, Biodentine was placed on the blood clot after filling the root canals with blood up to 4 mm below the CEJ. No dentin tubule occlusion procedure was applied for Blood and Biodentine groups. Color measurement was performed with the spectrophotometer Vita Easyshade Advance before treatment, immediately after treatment, and at days 7, 30, and 90. Data were converted to L*a*b color values of Commission International de I'Eclairage (CIE L*a*b) and ΔE values were calculated. Two-way ANOVA and post hoc Tukey test (p = 0.05) were performed for statistical analysis.

RESULTS

A clinically detectable color change was observed in all groups except for the negative control (ΔE ≥ 3,3). It was observed that Biodentine used alone has a potential for discoloration. It was determined that as the contact time with blood increased, tooth discoloration increased. However, no significant difference was found between dentin tubule occlusion methods in preventing color change (p > 0.05).

CONCLUSIONS

It was determined that no dentin tubule occlusion method could 100% prevent discoloration caused by RET.

CLINICAL RELEVANCE

DBA and Teethmate, which do not have a significant difference in terms of preventing color change, are considered to be suitable for dentin tubule occlusion due to their ease of application and low cost compared to Nd:YAG laser and Er:YAG laser.

Inhibition of Silver Diamine Fluoride-induced Tooth Discoloration by Using Natural Antioxidant: In Vitro Study

AIM

Silver diamine fluoride (SDF) is a well-known caries preventive aid capable of arresting carious lesions and preventing secondary caries formation. Despite having the caries prevention potential, the clinical use of SDF is limited due to the tooth discoloration caused by SDF. The objective of this study was to evaluate the efficiency of natural antioxidants to inhibit SDF-induced tooth discoloration.

MATERIALS AND METHODS

A total of 32 bovine teeth were polished to create a 6 mm circular window on the middle 1/3 (for enamel) or on the cervical 1/3 (for dentin) of the labial surface. Specimens were treated either with SDF alone or SDF followed by ascorbic acid (AA)/alpha lipoic acid (ALA)/7th generation bonding materials. The color parameters Lightness (L*), Chroma (C*), and Hue (H*) of the tooth window were measured at pretreatment, 1-hour, 1-week, and 1-month posttreatment using a digital color chromometer.

RESULTS

Repeated measure ANOVA showed a significant tooth color alteration at 1-hour posttreatment. The L* and H* values dropped and C* value elevated significantly in 1-hour posttreatment measurement. All experimental groups showed significant tooth color alteration after treatment (p < 0.05) and were unable to reverse the discoloration even after 1-month period except the ALA group which did not show any significant (p > 0.05) color alteration compared with the pretreatment value.

CONCLUSIONS

Within the limitation of the in vitro model and according to the results of this study, it can be concluded that ALA has the potential to prevent SDF-induced tooth discoloration; however, AA was unable to prevent the discoloration.

CLINICAL SIGNIFICANCE

SDF induces discoloration of enamel and dentin can be reversed by applying Alpha lipoic acid immediacy after SDF application.

Design and characteristics of new experimental chlorhexidine dental gels with anti-staining properties

BACKGROUND

Chlorhexidine-based products are often used in medicine and dentistry as dental hygiene and therapeutic products, especially by patients with various oral tissue diseases. However, these products have disadvantages, such as low stability, as well as discoloration of the teeth and dental reconstruction materials.

OBJECTIVES

The aim of this study was to create and evaluate experimental chlorhexidine (CHX) gels with anti-staining properties and to compare them with 3 commercially available products.

MATERIAL AND METHODS

For this study, 4 new formulations containing 1% CHX and different anti-staining agents were developed. The properties of these gels were compared with 3 commercial CHX-based dental products. The pH, viscosity, disintegration in water, and anti-staining properties were evaluated.

RESULTS

The pH level of the 4 new CHX gels ranged from 5.92 to 6.33. The viscosity of the experimental gels was higher (85.7÷217.7 Pa∙s) than the commercial ones (11.6÷72.7 Pa∙s). Among the experimental formulations with 1% CHX, the formulation with 5% polyvinylpyrrolidone (PVP) and 0.2% citric acid and the formulation with 1% citric acid were the most stable in terms of pH and viscosity. The disintegration times of the experimental gels were longer (50-70 min) as compared with the commercial products (approx. 20 min). These 2 CHX gels caused less color change of glass ionomer cements in black tea solution.

CONCLUSIONS

To conclude, 2 new experimental dental gels based on 1% CHX, one with 1% citric acid and the second with 5% PVP and 0.2% citric acid, had the most favorable physicochemical properties. Further research is needed to evaluate their therapeutic potential in the treatment of diseases of the oral cavity.

Crossover Clinical Trial of Tablets Containing Sodium Tripolyphosphate on Dental Stain Formation

OBJECTIVES

The purpose of this clinical investigation was to evaluate the effectiveness of sugar-free tablets containing sodium tripolyphosphate 2% or sodium tripolyphosphate 0.65%, compared to a no-tablet control in preventing the formation of extrinsic stains over a 12- week period of regular unsupervised use preserving daily oral hygiene with dentifrice and usual tooth brushing.

METHODS

This was a single-center, examiner-blind, randomized, 12-week crossover clinical trial. Sixty-six adult participants were enrolled in the study and were submitted to a professional cleaning to have a stain-free baseline. They either consumed two sugar-free tablets four times per day or not for 12 weeks. At the crossover, all procedures were repeated and subjects were assigned to another group. Extrinsic stain was measured at each 12-week period by the Modified Lobene Stain Index (MLSI).

RESULTS

After the three legs of 12 weeks, 60 subjects completed the trial, their MLSI stain scores showed a significant 35.5% reduction (p < 0.001) in new stain formation for those using the sodium tripolyphosphate 2% tablets, and a significant 23.3% reduction (p < 0.001) in new stain formation for those using the sodium tripolyphosphate 0.65% tablets versus the control group.

CONCLUSIONS

This clinical study showed that regular use of sugar-free tablets added with sodium tripolyphosphate 2% or 0.65% can reduce stain formation on the anterior teeth respectively by 35.5% (p < 0.001) or 23.3% (p < 0.001), both on facial and lingual/palatal surfaces.

Randomized controlled trial evaluating concurrent gingivitis and stain effects of a two-step dentifrice/gel sequence

PURPOSE

A randomized controlled trial was conducted to evaluate the clinical efficacy of a two-step dentifrice/whitening gel oral hygiene sequence on natural gingivitis and extrinsic stain.

METHODS

The population consisted of healthy adults with clinical evidence of gingivitis and extrinsic stain. Consent, demographic information and clinical measurements were collected, after which subjects were randomized to treatment. Eligible subjects were dispensed blinded test kits containing over-labeled two-step 0.454% SnF₂ dentifrice then 3% H₂O₂ whitening gel sequence or a regular 0.76% NaMFP dentifrice control (Colgate Cavity Protection), plus a regular soft manual toothbrush and instructions for use. Efficacy was assessed blind-to-treatment using the Gingivitis Bleeding Index (GBI) measured whole-mouth and the composite Lobene Stain Index (LSI) measured on the anterior dentition. Treatments were compared at Week 1 and Week 3 versus baseline for ΔGBI and ΔLSI using a two-sided 5% level of significance.

RESULTS

A total of 61 subjects with a mean (SD) age of 33.4 (12.0) years were enrolled. Overall baseline means (SD) were 0.16 (0.05) for GBI and 1.30 (0.94) for LSI. After 1 week, only the two-step 0.454% SnF₂ dentifrice then 3% H₂ O₂ whitening gel sequence demonstrated significant (P< 0.0001) reductions in both gingivitis and stain. Adjusted means for the changes with the dentifrice/gel sequence and control were -0.055 and -0.001 for ΔGBI, and -0.619 and -0.095 for ΔLSI, with groups differing significantly (P< 0.0001) on gingivitis and stain improvement. Outcomes at Week 3 were generally similar, with groups differing on bleeding and stain. Treatments were generally well-tolerated.

CLINICAL SIGNIFICANCE

In a randomized controlled trial, use of a two-step 0.454% SnF₂ dentifrice then 3% H₂ O₂ whitening gel sequence yielded concurrent improvements in gingivitis and stain compared to regular oral hygiene.

Can Coloured Fluoride Gel Stain Demineralised Enamel?

PURPOSE

This study evaluated the colour changes of demineralized enamel after treatment with coloured fluoride gel.

MATERIALS AND METHODS

Enamel blocks obtained from bovine incisors were submitted to artificial caries induction by pH cycling followed by fluoride gel applications (2% sodium fluoride, pH 6.8) using a colourless gel (control group), pink or blue gels. The enamel optical properties were evaluated by spectrophotometry, using the CIE L*a*b* system at baseline (sound enamel), after artificial caries induction (demineralised enamel) and after each of the five fluoride gel applications (weekly intervals). Changes in enamel optical properties (ΔE) were analysed by two-way ANOVA and Tukey's test (α = 0.05).

RESULTS

No significant differences were found among fluoride gels (p = 0.476) regardless of the presence of pigments in the gel. ΔE values were significantly different (p < 0.001) between baseline evaluation and treated enamel (after fluoride gel application).

CONCLUSION

This in vitro study demonstrated that colour changes in enamel do not occur during fluoride gel treatment, regardless of the presence or absence of coloured pigments in the gel.

Protection Against Discolouration by Two Over-the Counter Desensitising Products

PURPOSE

To determine in vitro the protection potential against discolouration of two OTC (over-the-counter) desensitising products on enamel and dentin in comparison to a standard toothpaste and water by means of a spectrophotometer.

MATERIALS AND METHODS

A total of 96 samples of bovine enamel-dentin complex and 48 of bovine dentin were alternatively immersed in red wine, tea, coffee or water after having been treated by a sodium monofluorophosphate- and calcium phosphate-based product (Curodont Protect), an amine fluoride-based toothpaste (Elmex Red), a stannous chloride-based toothpaste (Elmex Protection Erosion) or distilled water (negative control). Initial (T0) and final colour (T1, after 4 weeks of immersion in staining solutions) of each specimen were assessed by a spectrophotometer. Statistical analysis was done by means of repeated measures ANOVA followed by Fisher's LSD post-hoc test. Differences between T0 and T1 were considered stastistically significant at p ≤ 0.05.

RESULTS

When enamel samples were measured over a black background, ΔE00 values (T0-T1) varied from 2.2 (SD 0.7) for amine fluoride-based product/water to 53.9 (SD 7.6) for amine fluoride-based-product/red wine. When dentin samples were measured over a black background, ΔE00 values (T0-T1) varied from 5.4 (SD 0.9) stannous chloride based product/water to 61.6 (SD 3.7) amine fluoride-based product/red wine.

CONCLUSION

Specifically, the application of the sodium monofluorophosphate was able to statistically significantly (p ≤ 0.05) reduce discolouration induced by the staining solutions tested only on the enamel-dentin complex, while distilled water and the stannous fluoride-based product were able to statistically significantly (p ≤ 0.05) reduce discolouration induced by the staining solutions tested in pure dentin samples.

Silver diamine fluoride, potassium iodide, and esthetic perception: An in vitro pilot study

PURPOSE

To assess if there was a perceptible difference in staining of restorations in silver diamine fluoride (SDF)-treated teeth, with or without the subsequent application of potassium iodide (KI).

METHODS

20 extracted teeth with frank cavitated carious lesions were prepared with a spoon excavator to remove superficial soft carious dentin and then randomly divided into two groups of 10. The control group was treated with 38% SDF and then restored with glass-ionomer. The experimental group received similar treatment, with the additional step of KI applied before restoration. All teeth were subjected to 500 thermocycles between 5°C and 55°C, followed by storage in artificial saliva at 37°C for 30 days. Three blinded examiners evaluated all 20 teeth for intensity of staining on a scale from 0-5. Wilcoxon rank sum test compared average staining intensity between control and experimental groups of teeth as perceived by each examiner.

RESULTS

No significant differences were found (P values: 0.93, 0.67, and 0.97). An aggregate comparison of staining perception between control and experimental groups by repeated measure analysis was done treating the outcome as Poisson distribution also finding no significant difference (P= 0.82).

CLINICAL SIGNIFICANCE

The application of potassium iodide after silver diamine fluoride on caries-affected teeth may improve initial esthetic appearance, but after placement of a glass ionomer restoration, potassium iodide does not seem to result in any significant difference in staining.

Toothpastes containing abrasive and chemical whitening agents: efficacy in reducing extrinsic dental staining

This in vitro study evaluated the efficacy of toothpastes containing abrasive and chemical whitening agents in reducing the extrinsic discoloration of dental enamel. Sixty slabs of dentin from human teeth were sealed so that only the enamel surface was exposed. The enamel surfaces were photographed for initial color assessment. Staining was performed by immersing the dental slabs in 0.2% chlorhexidine solution for 2 minutes and then in black tea for 60 minutes. This process was repeated 15 times. Photographs were taken at the end of the staining process, and the slabs were divided into 5 groups (n = 12), 3 to be brushed with toothpastes containing chemical whitening agents (2 containing phosphate salts and 1 containing phosphate salts plus hydrogen peroxide) and 2 to represent control groups (ordinary/nonwhitening toothpaste and distilled water). The dental slabs were subjected to mechanical toothbrushing with toothpaste slurry or distilled water, according to each group's specifications. After brushing, more photographs were taken for color analysis. The results showed a significant reduction in luminosity after the staining process in addition to an increase in the colors red and yellow (P < 0.001). After brushing, there was a significant increase in luminosity and a reduction in both red and yellow (P < 0.001). However, there was no observed difference between the changes in color values in dental enamel slabs brushed with whitening toothpastes and the changes found in slabs brushed with ordinary toothpaste. The whitening toothpastes did not outperform an ordinary toothpaste in the removal of extrinsic staining.

Effects of Novel 3-dimensional Antibiotic-containing Electrospun Scaffolds on Dentin Discoloration

INTRODUCTION

Although intracanal application of the triple antibiotic paste (TAP) may offer advantages (eg, disinfection), this practice has been associated with significant drawbacks, including tooth discoloration. In this study, the color change of dentin was monitored during treatment with distinct TAP pastes and novel tubular-shaped 3-dimensional electrospun scaffolds containing minocycline (MINO) or doxycycline (DOX).

METHODS

Two TAP pastes (TAPMINO [MINO, metronidazole, and ciprofloxacin] and TAPDOX [DOX, metronidazole, and ciprofloxacin]), 4 scaffold-based groups containing MINO or DOX at distinct concentrations, 1 antibiotic-free scaffold, and 1 untreated group (control) were investigated. Human canines were sectioned at the cementoenamel junction and tubular-shaped scaffolds or paste were placed into the root canals and sealed. Color measurements (CIEL(*)a(*)b(*) parameters) were performed at baseline and after 1, 3, 7, 14, 21, and 28 days. Color changes were expressed as ΔE(*) values. In addition, scanning electron microscopy and energy-dispersive X-ray spectroscopy were also performed on the specimens after treatment. Data were analyzed using repeated measures analysis of variance (alpha = 0.05).

RESULTS

All antibiotic-containing groups led to greater discoloration than the antibiotic-free groups. A severe discoloration occurred after 1 day. At the end of the experiment, antibiotic-treated samples exhibited crusts/agglomerates over the dentin surface, which totally or partially obliterated the dentinal tubules. The presence of MINO resulted in a greater color change than DOX.

CONCLUSIONS

Scaffolds containing MINO or DOX produced similar color change to dentin when compared with their respective TAP systems, although DOX-related discoloration was less pronounced.

Dental plaque, gingival inflammation and tooth -discolouration with different commercial -formulations of 0.2% chlorhexidine rinse: a double-blind randomised controlled clinical trial

PURPOSE

To investigate the efficacy of various formulations of chlorhexidine 0.2% (CHX) in terms of plaque and gingival bleeding control compared to each other and to saline rinse (CTRL) over a 35-day rinsing period.

MATERIALS AND METHODS

Seventy subjects were randomly allocated to one of 4 groups rinsing twice daily for 35 days. The different groups used CHX 0.2% rinse with alcohol (CHX1) and without alcohol (CHX2), with an antidiscolouration system (CHX3) or saline rinse (CTRL). Clinical examinations to evaluate full-mouth plaque scores (FMPS) and periodontal parameters were performed at baseline, 7, 21 and 35 days. Tooth discolouration (TD) was measured at each time point using digital photographs and spectrophotometric analysis.

RESULTS

At 35 days, CTRL showed the highest levels of plaque. The mean changes in FMPS from baseline were 69.8% ± 6.8 for CHX1, 57.5% ± 9.8 for CHX2, 43.7% ± 9.8 for CHX3 and 25.8% ± 7.7 for CTRL. Statistically significant differences were demonstrated between CHX1 and CHX3 (p = 0.02), CHX2 vs CHX3 (p ≤ 0.05) and CHX1/CHX2 vs CHX3 (p < 0.05). In contrast, CHX3 appeared more effective in reducing inflammatory indexes. TD increased over time in 60% to 70% of participants, although lighter staining was found in the CHX3 group. Greater FMPS reduction was observed in participants with staining vs without staining (26.0% ± 12.3, p = 0.04).

CONCLUSION

Conventional CHX appeared more effective in terms of plaque reduction. Interestingly, the newest formulation showed a higher control of gingival inflammation. Staining was associated with lower plaque levels.

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).

[Keep an eye on the side effects]

A 52-year-old man presented with a progressive grey-black pigmentation of facial skin, sclera and teeth. The cause was long-term ingestion of minocycline, as confirmed by history and skin biopsy. Minocycline-induced hyperpigmentation can be divided into four main patterns based on clinical appearance, distribution, light- and electron microscopic characteristics. Some patterns can manifest within weeks of initiating therapy. One must be alert to the early signs and warn the patient about the often cosmetically disturbing and persistent minocycline-induced hyperpigmentation.

Management of the single discoloured tooth. Part 1: Aetiology, prevention and minimally invasive restorative options

The single discoloured tooth is commonly encountered in general practice. This is the first of two articles covering the broad range of management options for the single discoloured tooth. This first part outlines the common causes of discoloration and possible methods of prevention. Minimally invasive techniques are covered. Clinical procedures are outlined and clinical cases used to demonstrate outcomes that can be achieved.

CLINICAL RELEVANCE

The single discoloured tooth is a commonly encountered clinical problem in general dental practice. A wide variety of management options exist and any one in particular may be most appropriate given the clinical scenario. It is therefore essential that general dental practitioners are familiar with the range of options that exist, as well as their indications, and consider adopting minimally invasive techniques in the first instance before moving to more invasive therapies.

Placebo-controlled clinical trial evaluating 9.5% hydrogen peroxide high-adhesion whitening strips

OBJECTIVE

To evaluate the effectiveness and tolerability of an experimental 9.5% hydrogen peroxide whitening strip relative to a placebo control over a three-week period.

METHODS

In this parallel-design, double-blind clinical trial, 54 adult volunteers were randomized to an experimental 9.5% hydrogen peroxide whitening strip or placebo strip balancing for age and baseline tooth color, and received treatment. Strips were worn on the maxillary arch 30 minutes daily for 20 days. Efficacy was measured objectively as L*a*b* color change from digital images at Days 4, 7, 15, and 21.

RESULTS

As early as Day 4 and at all subsequent visits, the 9.5% strip group experienced significant (p < 0.004) color improvement relative to placebo for b* and L* color parameters. The amount of color improvement increased with continuing peroxide strip use. Mean ± SE between-group differences in Ab* were -0.6 ± 0.16, -0.8 ± 0.15, -1.6 ± 0.19, and -1.9 ± 0.20 at Days 4, 7, 15, and 21, respectively. Similar results were noted for AL*. Minor tooth sensitivity was the most common adverse event, as reported by 12% of subjects in the 9.5% strip group and 11% of subjects in the placebo group. No subjects discontinued treatment due to an adverse event.

CONCLUSION

This placebo-controlled clinical trial demonstrated that an experimental 9.5% hydrogen peroxide strip yielded significant tooth whitening relative to a placebo strip as early as after three days of product use.

Anti-calculus and whitening toothpastes

In terms of novel formulations, there seems to have been a shift in emphasis from anti-caries/anti-gingivitis to anti-calculus/whitening toothpastes in recent years. The anti-calculus and whitening effects of toothpastes are to some extent based on the same active ingredients: compounds of high affinity for tooth mineral. Due to this affinity, crystal growth may be hindered (anti-calculus) and chromophores be displaced (whitening). Besides these common ingredients, both types of toothpaste may contain agents specifically aimed at each condition. Clinical studies have shown that these active ingredients can be successfully formulated in fluoride toothpastes to give significant reductions in supragingival calculus and stain formation and facilitate their removal. Some of the ingredients are formulated in toothpastes that additionally contain anti-plaque and anti-gingivitis ingredients, making these toothpastes (together with the fluoride) truly multi-functional. The development of these products is not straightforward because of interaction between formulation components and because the active ingredients must maintain their beneficial characteristics during the shelf life of the paste. Neither a therapeutic benefit (in terms of less gingivitis or less caries) nor a societal benefit (in terms of less treatment demand) has been demonstrated as a result of the anti-calculus and whitening effects of toothpastes.

A randomized clinical study investigating the staining profile of an experimental stannous fluoride dentifrice

PURPOSE

The primary objective of this study was to investigate the staining profile of an experimental test dentifrice containing 0.454% w/w stannous fluoride compared to that of a marketed control dentifrice containing 0.76% w/w sodium monofluorophosphate (Colgate Cavity Protection) following regular and repeat use, with twice daily brushing over 8 weeks. As an exploratory objective, the staining profile of the test dentifrice was compared to that of a marketed comparator dentifrice containing 0.454% w/w stannous fluoride (Crest Pro-Health - Clean Mint).

METHODS

This was a single-center, examiner-blind, randomized, three arm, parallel group study, stratified by pre-baseline stain score [total Lobene Stain Index (LSI) (area x intensity) score < 31, > or = 31] and smoking status. Following initial screening, 137 healthy subjects, aged 18 years and above, with 12 gradable anterior teeth returned for baseline assessments. At the baseline visit, subjects received an oral soft tissue (OST) examination and an assessment of extrinsic dental stain using the LSI on the facial and lingual surfaces of the 12 anterior teeth, LSI area, LSI intensity and LSI area x intensity (the LSI area x intensity score was termed the pre-baseline LSI score). Subjects who met study requirements received a dental prophylaxis of the anterior teeth to remove all visible stain from their tooth surfaces such that an LSI (area x intensity) score of 0 was achieved. Randomized subjects brushed with their assigned dentifrice at home twice daily for 1 timed minute and returned after 4 and 8 weeks for an OST examination and dental stain assessment of the anterior teeth using LSI.

RESULTS

There were no statistically significant differences in dental stain build-up between the test dentifrice containing 0.454% w/w stannous fluoride and a marketed control dentifrice (Colgate Cavity Protection), after 4 and 8 weeks of twice daily brushing, in terms of LSI area x intensity, LSI area or LSI intensity scores. Exploratory analysis indicated that the marketed stannous fluoride dentifrice (Crest Pro-Health) exhibited more dental stain build-up at 4 and/or 8 weeks compared to the other two study dentifrices. However, post-hoc analysis revealed an imbalance in LSI baseline stain levels between the treatment groups, with higher stain levels in the marketed comparator group, which made it difficult to draw robust conclusions from the exploratory data. This imbalance was not considered to impact the other study analyses. Study treatments were well tolerated.

Stannous fluoride dentifrices

Stannous fluoride has a long history of use in the improvement of oral health, and was the fluoride source first proven to provide anti-caries benefits when delivered from a dentrifrice formulation. This paper provides an account of the early use of stannous fluoride, primarily for an anti-caries benefit, and the subsequent attempts to formulate stannous fluoride into stable formulations where additional benefits of the stannous cation can be realized.

Case series: management of immature permanent teeth with pulpal necrosis: a case series

The management of immature permanent teeth with necrotic pulps has changed in recent years from apexification techniques to regenerative endodontic procedures, which enable apexogenesis with physiologic maturation of the roots. This regenerative technique lies squarely in the endodontist's scope of practice, but children presenting with necrotic immature incisors may pose behavior management problems that endodontists are untrained and unwilling to handle. Treatment of these immature permanent teeth provides an excellent opportunity for collaboration and shared patient management between pediatric dentists and endodontists that can yield optimal clinical outcomes. The purpose of this paper was to report a series of 32 regenerative endodontic cases in 28 children treated at the Nationwide Children's Hospital, Columbus, Ohio. The report describes procedural and patient management issues and the need for a collaborative relationship between pediatric dentists and endodontists in tackling these challenging cases.

The oral health benefits of chewing gum

The use of sugar-free gum provides a proven anti-caries benefit, but other oral health effects are less clearly elucidated. Chewing sugar-free chewing gum promotes a strong flow of stimulated saliva, which helps to provide a number of dental benefits: first, the higher flow rate promotes more rapid oral clearance of sugars; second, the high pH and buffering capacity of the stimulated saliva help to neutralise plaque pH after a sugar challenge; and, lastly, studies have shown enhanced remineralisation of early caries-like lesions and ultimately prospective clinical trials have shown reduced caries incidence in children chewing sugar-free gum. This paper reviews the scientific evidence for these functional claims and discusses other benefits, including plaque and extrinsic stain reduction, along with the possibility of adding specific active agents, including fluoride, antimicrobials, urea and calcium phosphates, to enhance these inherent effects. The evidence for a specific effect of xylitol as a caries-therapeutic agent is also discussed. In conclusion, it is asserted that chewing gum has a place as an additional mode of dental disease prevention to be used in conjunction with the more traditional preventive methods.

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

BACKGROUND

In addition to its general and periodontal health effects smoking causes tooth staining. Smoking cessation support interventions with an added stain removal or tooth whitening effect may increase motivation to quit smoking. Oral health professionals are well placed to provide smoking cessation advice and support to patients. The objective of the present study was to evaluate the effect of Nicorette(®) Freshmint Gum used in a smoking cessation programme administered in a dental setting, on extrinsic stain and tooth shade among smokers.

METHODS

An evaluator-blinded, randomized, 12-week parallel-group controlled trial was conducted among 200 daily smokers motivated to quit smoking. Participants were randomised to use either the Nicorette(®) Freshmint Gum or Nicorette(®) Microtab (tablet). Tooth staining and shade were rated using the modified Lobene Stain Index and the Vita(®) Shade Guide at baseline, weeks 2, 6 and 12. To maintain consistency with other whitening studies, the primary end-point was the mean change in stain index between baseline and week 6. Secondary variables included changes in stain measurements and tooth shade at the other time points the number of gums or tablets used per day and throughout the trial period; and the number of cigarettes smoked per day. Treatments were compared using analysis of covariance (ANCOVA), using treatment and nicotine dependence as factors and the corresponding baseline measurement as a covariate. Each comparison (modified intention-to-treat) was tested at the 0.05 level, two-sided. Within-treatment changes from baseline were compared using a paired t-test.

RESULTS

At week 6, the gum-group experienced a reduction in mean stain scores whilst the tablet-group experienced an increase with mean changes of -0.14 and +0.12 respectively, (p = 0.005, ANCOVA). The change in mean tooth shade scores was statistically significantly greater in the gum-group than in the tablet group at 2 (p = 0.015), 6 (p = 0.011) and 12 weeks (p = 0.003) with greater lightening in the gum-group at each examination period.

CONCLUSION

These results support the efficacy of the tested nicotine replacement gum in stain reduction and shade lightening. These findings may help dentists to motivate those wishing to quit smoking using a nicotine replacement gum.

TRIAL REGISTRATION

NCT01440985.

Adverse effects associated with the clinical use of 4% TiF₄ on teeth enamel: case report

Titanium tetrafluoride (TiF₄) has been studied in dentistry as a promissory alternative for prevention and treatment of carious lesions. However, there are few in vivo studies concerning the consequences of its use on tooth enamel. The goal of this study was to report the effects of a 4% TiF₄ application on the remineralization of an incipient carious lesion of a permanent tooth. This research found an unexpected clinical outcome. A patient with active white spots had two of these lesions treated with 4% TiF₄ associated with fluoridated dentifrice and another lesion treated with fluoridated dentifrice only, thus the remineralization of the two kinds of treatment administered could be observed and compared. An extrinsic pigment appeared in the regions that received the TiF₄ treatment, which was partially removed by professional prophylaxis. Also, regular recidivists of this pigmentation in the review consultations were noted. The authors concluded that although the use of 4% TiF₄ was effective in treating incipient carious lesions on enamel, it was also responsible for an undesired pigmented layer on the tooth to which it was applied. Beyond the varied fluoridated materials used in dentistry, titanium tetrafluoride (TiF₄) deserves attention. This compound has the common properties of fluorides, and researchers are exploring its role in carious lesion prevention, fissure sealing, and tooth erosion prevention in in vitro and in situ studies. Research is also exploring its use for microinfiltration prevention in tooth restoration and hypersensitivity treatment. However, when compared to other fluoridated products TiF₄ demonstrates additional, specific particularities, such as the formation of a titanium dioxide (TiO₂) layer, which is tough, hydrophobic, and resistant in acidic environments. Nevertheless, there are insufficient in vivo studies concerning the consequences of TiF₄-containing products affecting tooth enamel. Thus, the goals of this study were to report the effects of a 4% TiF₄ application on the remineralization of an incipient carious lesion of a permanent tooth and to show the results of a backscattered scanning electron (BSE) analysis that was performed on the primary tooth. The clinical outcome was unexpected.

In vitro effect of chlorhexidine mouth rinses on polyspecies biofilms

The aim of this study was to use the Zurich polyspecies biofilm model to compare the antimicrobial effects of chlorhexidine mouth rinses available on the Swiss market. As positive and negative controls, aqueous 0.15% CHX solution and water were used, respectively. In addition, Listerine® without CHX was tested. Biofilms in batch culture were grown in 24- well polystyrene tissue culture plates on hydroxyapatite discs in 70% mixed (1:1 diluted) unstimulated saliva and 30% complex culture medium. During the 64.5-hour culturing period, the biofilms were exposed to the test solutions for 1 minute twice a day on two subsequent days. Thereafter, the biofilms were dip-washed 3 times in physiological NaCl. Following the last exposure, the incubation of biofilms was continued for another 16 h. They were then harvested at 64.5 h. The dispersed biofilms were plated on 2 agar media. After incubation, colonies (CFU) were counted. All solutions containing CHX as well as Listerine ® significantly reduced the number of microorganisms in biofilms. According to their efficacy, the mouth rinses were classified into 2 groups. The two Curasept ADS solutions, Parodentosan, and the Listerine® mouth rinse reduced the number of total CFU by 3 log10 steps. This seems sufficient for a long-lasting prophylactic application. The two PlakOut® mouth rinses and the CHX control fell into the other group, where the number of CFU was reduced by 7 log10 steps. These mouth rinses are predestined for short-term therapeutic use. However, reversible side effects must be taken into account. It has thus far not been possible to formulate CHX products with effective ADS (Anti Discoloration System) additives without reducing antimicrobial activity.

Effect of toothpaste containing d-limonene on natural extrinsic smoking stain: a 4-week clinical trial

PURPOSE

To determine whether natural smoking stain could be removed/inhibited effectively by a toothpaste containing 5% d-limonene. For comparison and contrast, the effects of d-limonene on tea stain were also assessed.

METHODS

The design was a randomized controlled double-blind trial with parallel groups. Toothpastes were: A: positive control with perlite whitening formulation; B: A+5% d-limonene; C: D + 5% d-limonene; D: negative control. The extrinsic stains were measured using Lobene Stain Index. Following baseline examination, all subjects were randomly assigned to one of the four toothpaste groups and instructed to brush with the assigned products twice daily. Subjects returned to the clinic after 4-week brushing for stain removal assessment, then all extrinsic stains, plaque and supragingival calculus were removed and use of assigned products was continued for another 4 weeks, and the stain scores were repeated for inhibition assessment.

RESULTS

A total of 408 subjects, 201 with smoking stains and 207 with tea stains, participated in the trial. 5% d-limonene combined with Perlite whitening formulation significantly reduced stain scores both for smoking stain removal and inhibition (P < 0.05). Furthermore, 5% d-limonene alone (in negative formulation) exhibited an additional advantage for smoking stain inhibition (P < 0.05), but the advantage was not found for long-standing smoking stain removal (P > 0.05). The additional advantage of 5% d-limonene was shown neither for removal nor for inhibition in the tea stain study (P > 0.05). All test products were well tolerated over the study period.

Effect of surface sealant and repolishing procedures on the color of composite resin exposed to cigarette smoke

This study evaluated the effect of cigarette smoke on the color of composite resins, with and without the application of a surface sealant and before and after the restorative material was repolished. Twenty composite resin specimens were divided into two groups (n = 10); one of which received a surface sealant. Both groups were exposed daily to the smoke of 20 cigarettes. Color analyses were performed using a spectrophotometer at different intervals: prior to cigarette smoke exposure (baseline), 21 days after cigarette smoke exposure, and after the specimens were repolished using aluminum oxide discs. Cigarette smoke caused a decrease in lightness (L*), especially in samples that received the sealant (p = 0.014). At 21 days, there was an increase in yellow pigment for both groups, with higher values (p = 0.00001) and predominant red pigmentation in the samples that received sealant. An increase in lightness and a decrease in yellow pigments (p < 0.05) were reported in both groups after repolishing. Cigarette smoke significantly altered the color of the composite resin (DeltaE > or = 10.34), especially in the specimens that received the sealant. In this study, the sealant tested intensified cigarette staining, and although repolishing decreased surface pigmentation, it was unable to restore the original color of the composite resin.

Effect on dental stain occurrence by chewing gum containing sodium tripolyphosphate--a double-blind six-week trial

OBJECTIVE

A six-week controlled double-blind clinical study was conducted to assess and to measure the efficacy of a sugar-free chewing gum containing sodium tripolyphosphate (1%) on dental stain occurrence versus a placebo sugar-free chewing gum.

METHODS

One-hundred and eleven subjects who had a Lobene Modified Index for stain extent score between 0.33 and 1.5 in their frontal teeth joined this study. Each subject entered in the test or the control group using a random table which allowed for an equal distribution of smokers and habitual tea users. Participants agreed to chew two gums (two grams each) three times per day, after meals, for ten minutes over six weeks. All received the same dentifrice containing only fluoride as the active agent. After six weeks, participants were scored for dental stain with the Lobene Modified Index. Data were scored by the same blinded operator for all measurements. Comparisons between the groups with respect to baseline scores were performed using an unpaired t-test, and inside the groups with a paired t-test (alpha = 0.05).

RESULTS

One-hundred and eight subjects completed the trial; three left, but none reported problems linked to sodium tripolyphosphate. The mean difference for stain extent index after the six-week trial was 0.04 (+/- 0.08) in the control group, and -0.05 (+/- 0.08) in the test group (p < 0.001). A statistically significant reduction was also reported for intensity and composite indexes. The initial mean for stain extent index in the test group was 0.8 (+/- 0.34), and at six weeks was 0.74 (+/- 0.33; p < 0.001). The initial mean for extent index in the control group was 0.78 (+/- 0.3), and at six weeks was 0.81 (+/- 0.32; p < 0.005).

CONCLUSION

This trial showed a reduction in dental stain by a chewing gum containing sodium tripolyphosphate after six weeks.

Stannous fluoride dentifrice with sodium hexametaphosphate: review of laboratory, clinical and practice-based data

Dentifrice was originally used to promote oral hygiene by cleaning teeth. However, with advances in product formulation, it has become a valuable vehicle for the delivery of agents offering health and cosmetic benefits. Stannous fluoride, introduced in 1955 in dentifrice, is one of the longest established of such agents. The well-known anti-caries efficacy of stannous fluoride is based on its impact on the tooth surfaces and on its antibacterial activity. More recently, the demand for tooth whitening products has increased, and sodium hexametaphosphate has been shown to be helpful in whitening surface stains and in controlling calculus. A dentifrice formulation that combines the benefits of stannous fluoride with those of sodium hexametaphosphate is now available. A review of the evidence shows that in addition to effective anti-caries action, this formulation is effective in fighting plaque, gingivitis, and gingival bleeding while inhibiting calculus and extrinsic stain. A practice-based evaluation including data from over 1,200 dental professionals and 1,000 patients demonstrates the product's benefits and excellent acceptability. Collectively, the research shows this stannous fluoride/sodium hexametaphosphate dentifrice provides multiple benefits to meet the oral health and cosmetic needs of patients.

Ion uptake into demineralized dentine from glass ionomer cement following pretreatment with silver fluoride and potassium iodide

BACKGROUND

Diamine silver fluoride (Ag(NH3)2F), referred to as AgF, has been shown to provide a pronounced antimicrobial action against caries. The clinical application of this material has been limited by the staining associated with both teeth and tooth coloured restorative materials. The application of potassium iodide (KI) after AgF eliminates stain formation. The purpose of this study was to determine if a prior application of silver fluoride and potassium iodine to demineralized dentine affected the uptake of strontium and fluoride from a glass ionomer cement restoration.

METHOD

Three cavities were prepared in each of five recently extracted human third molars. The cavities were demineralized and treated as follows. In each tooth, one cavity was left as a control, one cavity was restored with glass ionomer cement and one cavity was treated with 1.8M AgF and a saturated KI solution and then restored with glass ionomer cement. The penetration of the various elements into demineralized dentine was measured by their relative percentage weights using electron probe microanalysis (EPMA).

RESULTS

Fluoride uptake was significantly higher in the AgF and KI treated samples compared to the other two samples and significantly higher in the glass ionomer restored sample compared to the control. The application of AgF and KI did not significantly interfere with the transfer of strontium from glass ionomer cement into dentine. Silver and iodine deposits were present in the demineralized dentine treated with AgF and KI.

CONCLUSIONS

The application of AgF and KI onto dentine prior to the placement of glass ionomer cement did not significantly affect the strontium uptake into the subjacent demineralized dentine and the fluoride levels in this zone were significantly increased.

Clinical studies to assess the extrinsic stain prevention and stain removal efficacy of a variant of a commercially available dentifrice containing a new dual silica system

OBJECTIVE

The objective of these two six-week, double-blind clinical studies was to compare the extrinsic stain prevention (Study #1) and stain removal (Study #2) efficacy of a new dentifrice (Colgate Total Advanced Toothpaste) containing 0.3% triclosan/ 2.0% polyvinylmethyl ether/maleic acid (PVM/MA) copolymer/0.243% sodium fluoride in a 17% dual silica base, to a commercially available fluoride dentifrice without tooth whitening ingredients (Crest Cavity Protection Toothpaste) containing 0.243% sodium fluoride in a silica base.

METHODS

Following baseline examinations for extrinsic tooth stain and an oral tissue examination, qualifying adult male and female subjects from the northern and central New Jersey, USA areas were randomized for each study into two treatment groups which were balanced for gender and level of extrinsic tooth stain. Subjects received a full oral prophylaxis at the start of Study #1 only. All subjects were provided with their assigned product and a soft-bristled adult toothbrush for home use. Subjects were instructed to brush their teeth for one minute twice daily (morning and evening) using only the dentifrice and toothbrush provided, and to refrain from using any other oral hygiene products for the entire six weeks of the study. There were no restrictions regarding diet or smoking habits during the course of the study. Examinations for extrinsic tooth stain and oral tissue assessments were repeated after three weeks and six weeks of product use.

RESULTS

One-hundred fourteen (114) subjects participating in Study #1 and 119 subjects participating in Study #2 complied with the protocol and completed the entire study. In both studies, at the three-week and the six-week examinations, subjects who used the new dentifrice exhibited statistically significantly lower levels of extrinsic tooth stain area and extrinsic tooth stain intensity than did those subjects who used the commercially available fluoride control dentifrice.

CONCLUSION

A new dentifrice containing 0.3% triclosan/2.0% PVM/MA copolymer/0.243% sodium fluoride in a 17% dual silica base is more efficacious in the prevention and removal of extrinsic tooth stain than a commercially marketed fluoride dentifrice.

Extrinsic stain removal efficacy of a dual-phase dentifrice

PURPOSE

To evaluate the extrinsic stain removal benefit of a sodium hexametaphosphate containing dual-phase dentifrice (Crest Vivid White) relative to a marketed negative control (Colgate Cavity Protection).

METHODS

This was a parallel groups, examiner-blind, randomized and controlled clinical trial. A total of 200 healthy adults with natural stain on their anterior teeth were enrolled into the study. Following baseline examination, subjects were randomly assigned to one of the two treatment groups based on baseline Lobene composite scores, smoking status (yes/no), tea/coffee consumption (yes/no), and gender. Subjects brushed twice daily, at least 1 minute every time over 6 weeks. Clinical examinations including extrinsic stain evaluation and oral soft tissue examination were conducted at BL, Weeks 3 and 6. Extrinsic stain removal was evaluated on the anterior teeth by a dental examiner using Lobene stain index.

RESULTS

Of the 200 subjects who were randomized to treatment, 195 were available for the 3-week examination and 193 subjects completed the study. The dual-phase dentifrice exhibited a statistically significant (P< 0.01) reduction in Lobene stain composite scores when compared to the negative control dentifrice at Week 6. Adjusted mean Lobene composite reduction for the dual-phase dentifrice group (0.32) was twice as big as the negative control group (0.16). Change in Lobene stain extent (area) contributed primarily to the overall composite score reduction. All test products were well tolerated over the 6-week treatment period.

Combined effects of staining substances on resin composites before and after surface sealant application

The objective was to measure the combined effect of mucin, chlorhexidine and tea solution on the staining of four dental resin composites, and to determine the effect of surface sealant on staining. One side of cured resin composite specimens of 10 mm in diameter and 2 mm in thickness were polished with 600-grit silicon carbide paper. One group of specimens (n = 5) was treated with a surface sealant [BisCover, Bisco, USA; SS (surface sealant) group], and the other group was not (NO group; control). Specimens were sequentially immersed in the following substances: Mucin in phosphate buffered saline (PBS); chlorhexidine; tea solution; and ultrasonic cleaning and then immersion in PBS. Color was measured on a reflection spectrophotometer. Changes in color (DeltaE (*) (ab)) and color parameters, such as hue, chroma and value, after immersion in tea solution and subsequent cleaning were analyzed by repeated measures, analysis of variance at the 0.05 level of significance. The range of DeltaE (*) (ab) values after immersion in tea solution was 11.4-21.1 for NO group and 10.5-19.6 for SS group, and that after cleaning was 2.4-10.0 for NO group and 2.7-8.3 for SS group. After staining, CIE L (*) value (lightness) decreased, and CIE a (*) and b (*) values increased. Color changes of resin composites were not acceptable after sequential immersion treatment (DeltaE (*) ( ab ) > 3.3). The changes in color and color parameters of sealant applied group were not significantly different from those of control group except for a few combinations of color parameters and resin composites.

The effect of different fluoridation methods on the red wine staining potential on intensively bleached enamel in vitro

PURPOSE

To study the effect in vitro of different fluoridation methods after intensive bleaching on the color of enamel slabs during a severe staining challenge with red wine.

METHODS

75 specimens were equally divided among five groups. Group 1 (no bleaching, no wine) served as control. Groups 2, 3 and 4 underwent bleaching with 35 % H2O2 for 10 minutes followed by home-bleaching for 8 hours/day with 10% carbamide peroxide on 14 consecutive days. Groups 2 and 3 were fluoridated for 1 hour with either Elmex gelée or Duraphat, respectively whereas Group 4 remained without fluoridation. Group 5 (no bleaching, no fluoride, wine) served as control for the influence of red wine on the color of untreated enamel. Color determination was accomplished using the CIE-Lab System.

RESULTS

Nine successive cycles of wine saliva treatment (10 minutes wine, 23 hours 50 minutes saliva) for Groups 2-5 revealed the highest changes of a-values (deltaa= 4.17) (towards red) for the Duraphat-treated group (bleaching, Duraphat, wine) with significantly higher deltaa-values compared with Group 4 (bleaching, no fluoride, wine) (deltaa= 2.97). After final cleaning no differences were found between the three bleached groups (Groups 2, 3 and 4) for deltaL, deltaa, deltab and deltaE, respectively. Exposure to red wine led to an increase in a-values (deltaa= 0.44) of the intrinsic tooth color in Group 5 (no bleaching, no fluoride, wine) that was significantly different from baseline.

Potential Iatrogenic Tetracycline Staining of Endodontically Treated Teeth via NaOCl/MTAD Irrigation: A Preliminary Report

This study reported red-purple staining of light-exposed, root-treated dentin when root canals were rinsed with 1.3% NaOCl as initial rinse followed by the use of BioPure MTAD as final rinse. This intrinsic dentin staining occurred irrespective of whether the root canals were filled, and could be observed even in crown dentin when the latter was sequentially immersed in NaOCl and MTAD. Bench-top reproductions of the phenomenon revealed that the exothermic reaction is not an acid-base reaction. Conversely, the reaction is of a redox nature that highly resembled the previously reported mechanism of tetracycline staining, in which photo-oxidation of tetracycline resulted in a red-purple tetracycline degradation product that has a high affinity for hydroxyapatite. This photo-oxidative degradation process is probably triggered by the use of NaOCl as an oxidizing agent, and may be prevented by rinsing the NaOCl-treated dentin with ascorbic acid, a reducing agent, before the application of MTAD.

Self-bonding polymers as surface coatings of restorative resins to prevent staining

OBJECTIVE

Discoloration caused by staining of resin restorations can pose a serious esthetic problem. The aim of this study was to evaluate the efficacy of a self-bonding polymer (KISSCARE) in reducing extrinsic stains in an in vitro study model.

METHODOLOGY

Thirty-six specimen disks were prepared using a composite resin (Vitalescence: shade A2 and A4), and divided into three experimental groups with different surface coatings: Group 1--Control (no coating); Group 2--Self-bonding polymer (SBP; KISSCARE Concentrated Gel), and Group 3--Composite Sealer (PermaSeal). These groups were further divided into Brushing and Non-brushing subgroups. The specimens in the Brushing groups were brushed daily with 40 strokes in two directions at a 90-degree angle using a toothbrush. Specimens were immersed in a coffee solution at 37 degrees C in a dark environment for 10 days. The color changes of each group were quantitatively measured using a spectrophotometer. Means and standard deviations were calculated, and data were analyzed using ANOVA/Scheffe post-test.

RESULTS

The SBP group showed less color change compared to the Control and the Sealer groups (p < 0.05). The Sealer group resulted in greater discoloration compared to the Control and the SBP group (p < 0.01).

CONCLUSION

Application of self-bonding polymers was an effective method of surface coating in reducing staining of restorative resins, especially in the absence of brushing procedures.

Whitening effect by stain inhibition from a chewing gum with sodium hexametaphosphate in a controlled twelve-week single-blind trial

OBJECTIVE

A twelve-week clinical study was conducted to assess the effect of a chewing gum containing sodium hexametaphosphate (4%) on the inhibition of stain formation.

METHODOLOGY

Fifty-four subjects were entered and completed all aspects of the study. Twenty-seven of the subjects were smokers, and the other half did not smoke. Subjects were randomly assigned to the test gum or no-gum group. Each participant received a full oral prophylaxis at the beginning of each period of observation. Those chewing the test gum agreed to chew four times a day, for five minutes each time, over twelve weeks. Those assigned to the no-gum group agreed not to chew any gum. After twelve weeks, participants were scored for stain deposits (Lobene Index), received a second oral prophylaxis, and joined the alternate group in this cross-over format. At the end of the twenty-fourth week, all subjects were again scored for stain deposits and the study was completed. In order to enhance stain formation during the entire 24-week study period, all participants received a supply of a chlorhexidine (0.12%) dentifrice without anionic agents to use three times a day. Stain levels were scored by the same examiner for all measurements and recorded on computer. The examiner was blinded to all treatment assignments.

RESULTS

There were no reported problems associated with the chewing gum. The Lobene Index mean score for stain extent was 0.54 +/- 0.36) in the test-gum group and 0.81 +/- 0.47) for the no-gum group. The difference between the mean scores was highly significant with paired sample t-test (p < 0.001). Mean stain intensity was 0.57 +/- 0.38) in the test group and 0.95 (+/- 0.72) in the control group, with a statistically significant difference at p < 0.01.

CONCLUSION

The results indicated that chewing gum containing sodium hexametaphosphate reduced induced stain formation by 33% compared to a no-gum treatment.

An in vitro model to measure the effect of a silver fluoride and potassium iodide treatment on the permeability of demineralized dentine to Streptococcus mutans

BACKGROUND

Diamine silver fluoride (Ag(NH3)2F), referred to as AgF, has been used to reduce the incidence of caries in primary dentitions but has been limited by the associated staining of both teeth and restorative materials. The application of potassium iodide (KI), following AgF prevents staining but its effects on the ability of AgF to reduce caries are not known. The aim of this study was to develop an in vitro model that would provide an indication of the permeability of demineralized dentine to Streptococcus mutans after treatment of the dentine with AgF followed by KI.

METHODS

Forty dentine discs were bonded to the base of forty 5mL polycarbonate screw top vials (that had had their bases removed), filled with nutrient medium, sterilized and placed into a continuous culture of S. mutans. Samples were divided into four groups as follows: 10 samples of demineralized dentine as a control, 10 samples of demineralized dentine treated with AgF/KI, 10 samples of demineralized dentine treated with KI and 10 samples of demineralized dentine treated with AgF. After two weeks the optical density of the growth medium chambers was measured to determine bacterial penetration and growth. Cultures were plated out to determine migration through the discs by S. mutans.

RESULTS

S. mutans migrated through all dentine discs. However, the samples treated with AgF and AgF/KI had significantly lower optical densities than the corresponding controls. The range of optical densities was least amongst demineralized samples treated with AgF/KI.

CONCLUSIONS

Under the conditions of this study, treatment of demineralized dentine discs with AgF followed by KI allowed the penetration of S. mutans. Based on optical density measurements, the treatment resulted in significantly fewer microorganisms being present subjacent to the discs treated with AgF and KI than the control discs at the end of the experimental period.

A comparative study of white and grey mineral trioxide aggregate as pulp capping agents in dog's teeth

Mineral trioxide aggregate (MTA) is widely used for different perforation repairs, root-end filling, pulp capping and many other endodontic procedures. Because of potential discoloration effect of gray MTA, white MTA has been introduced into endodontic treatment for the same purposes. This study examined the dental pulp responses in dogs to both types of MTA used as a pulp-capping agent. The pulps of 24 teeth of four male dogs were exposed with a No.1 round bur and capped with either gray or white MTA. Histologic analysis was performed one and 2 weeks after treatment. Calcified bridge could be seen 1 week after treatment with both types of MTA, with no significant differences between the two treatments.

Results after replantation of avulsed permanent teeth. I. Endodontic considerations

Following avulsion and replantation, teeth are at risk for infection and infection related resorption (IRR). Severe discolorations of tooth crowns and cervical root fractures are common. This study presents data on endodontic related complications of avulsed teeth replanted following an extraoral endodontic treatment. Periodontal aspects will be discussed in the second part of the present publication. Twenty-eight permanent teeth in 24 patients aged seven to 17 years were replanted after avulsion. All teeth could be evaluated. In all teeth extraoral endodontic treatment by retrograde insertion of ceramic or titanium posts was performed. Mean observation period was 31.2 months (median: 24.1 months). Nine teeth healed with a functional periodontal ligament (PDL) (functional healing, FH), 19 teeth exhibited replacement resorption (RR), which was succeeded by IRR in three teeth after observation periods of more than 14 months. Diagnosis was set to tunneling resorption (one case) and to cervical resorption preceded by complete RR (two cases). No early IRR was observed. All six teeth rescued in physiologic conditions (cell culture medium of tooth rescue box) exhibited FH. Discolorations of tooth crowns or other complications (cervical root fractures, fractures of posts) were not observed. No differences in the healing results of immature and mature teeth were observed which is in contrast to previous studies. This finding is explained with the different endodontic treatment protocols. Extraoral endodontic treatment by retrograde insertion of posts prevents early IRR and minimizes the overall incidence of IRR. The method does not negatively influence periodontal healing. As there are further advantages (no discoloration, no root fractures, patient not involved, less radiographs, less time consumption, less costs) the method is recommended in isolated teeth before replantation. Especially immature teeth profit from the prevention of complications.