Extrinsic Stain Research Articles

Procedures And Adverse Effects Of Teeth Whitening

Now a days people are giving much more importance to perfect smiles. Expectations about aesthetic appearance has been increasing day by day in the recent times. Aesthetic smiles including tooth colour and appearance is very important to patients. So teeth whitening procedures are one of the most frequently demanded treatment options by public. Besides oral health and hygiene, there is an increasing number of oral care products that focus on teeth whitening. There are various reasons for people to choose teeth whitening as a treatment option which includes: staining of teeth which may include extrinsic or intrinsic stains, to improve their smiles etc. Among all of these, teeth discolouration is the most common cause. Discolouration of teeth are mostly associated with staining. Therefore, excellent approach to discolouration of teeth is teeth whitening techniques. There are various procedures of teeth whitening. Here we are going to discuss about vital and non-vital teeth whitening techniques which is also called bleaching and the adverse effects associated with these procedures. Both vital and non-vital teeth whitening procedures come up in in either at-home technique or in-office procedure and over-the- counter modalities. carbamide peroxide, hydrogen peroxide or sodium perborate are the different types of chemical agents that are being used for these procedures which are going to be discussed in the coming sections. These procedures not only produce excellent whitening effects but also some of the adverse effects which are discussed in this paper. Finally, the result of the treatment is whiter teeth and perfect smiles. Dentist plays an important role to bring about a perfect smile on people’s face

Combination bleaching technique for an aesthetic upgrade in vital teeth- A case report of two cases

Teeth stains can broadly be classified into two types; Extrinsic and Intrinsic stains, the latter being harder to remove. The etiology of discolouration is vast which could be due to diet, medication, fluorosis or any systemic illness. Extrinsic stains are mainly on the outer surface of the tooth (Ex: Tea stains, Tobacco stains) and Intrinsic stains are present mainly within the tooth structure (Ex: systemic stains, fluorosis). Tooth bleaching is a cosmetic dental procedure aimed at improving the aesthetics of the smile and thereby increasing the patient satisfaction. This case report documents the successful application of a combination therapy for vital tooth bleaching by using walk in bleach as well as laser bleaching for the patients aesthetic considerations

Competitive swimming and dental staining among Australian children.

Swimming has classically been associated with a distinctive type of extrinsic dental staining. However, its prevalence and characteristics have not been explored in Australia. This case controlled cross-sectional cohort study aimed to determine the prevalence and severity of dental staining among children who swim competitively compared to non-swimmers and its impact on oral health-related quality of life (OHRQL). Parents and children from Western Australian swimming clubs completed a survey assessing swimming routine, risk factors for staining and OHRQL. Intra-oral photographs were taken and staining of anterior teeth was assessed using a modified Lobene Stain Index. A Global Stain Score (GSS) was calculated and compared against age-matched non-swimmer controls. Maxillary anterior teeth from swimmers (n = 400) and non-swimmers (n = 400) were analysed. Staining prevalence was greater in swimmers (83%) than non-swimmers (44%). GSS scores were positively correlated with both the total lifetime swimming hours and practice time (P < 0.05), with a significant difference in GSS between swimmers and non-swimmers (P = <0.001, OR: 6.21). Dietary factors for staining were not significantly correlated with GSS. Swimmers had a greater risk of developing staining than non-swimmers, and this negatively impacted their OHRQL. The extent and intensity of staining were associated with the amount of swimming.

Potency of Strawberry Extract (Fragaria X Annanassa) as Stain Removal Strips Against Extrinsic Stain on the Surface of the Teeth of Adolescents Aged 18-25 Years

Extrinsic stain is a staining of teeth that is attached directly to the surface of the tooth. Disorders caused by stains are causing aesthetic problems that can have a considerable psychological impact, especially if they occur in the anterior tooth. Stains are difficult to clean just by brushing your teeth. Utilizing natural strawberry ingredients as Stain Removel Strips for an alternative to cleaning extrinsic stains on the surface of teeth. Objective: Proven administration of Stain Removal Strips strawberry extract (Fragaria x Ananassa) effectively cleans extrinsic stains on the surface of teeth. Method: This study used the Quasy experimental method with a pretest posttest design with control group. Research sampling was carried out by purposive sampling. The sample consisted of 20 people divided into 2 groups. The control group with 6% hydrogen peroxide strips and the intervention group with 40% strawberry extract stain removal strips twice a day with a duration of 30 minutes for 7 days. Results: The results showed that giving strawberry extract Stain Removal Strips was 40% effective in cleaning extrinsic stains on day 3 and day 7 against extrinsic stains on the tooth surface with values of p = 0.009 and p = 0.002 (p &lt; 0.05) compared to the control group. Conclusion: Stain Removal Strips 40% strawberry extract has potential as an alternative to cleaning extrinsic stains on tooth surfaces.

Development of optical coherence tomography incorporated image processing algorithms for the multidimensional assessment of concealed enamel micro-crack

Enamel microcracks (EMCs) are tiny fractures that occur in the outer layer of teeth, allowing some extrinsic stains and leading to an unaesthetic tooth. Additionally, the EMCs enhance the accumulation of plaque and thus EMCs could be highly suspectable zones for caries development. Therefore, the assessment of EMCs is crucial for early diagnosis and to prevent unwanted damage to teeth. In this study, a concealed EMCs detection and length-measuring algorithm, and an EMCs width-measuring algorithm were applied for optical coherence tomography (OCT) image analysis to assess the EMCs progression in both length and width. Additionally, a surface noise-removing algorithm was developed to obtain a better visualization of OCT cross-sectional and volumetric images. The developed algorithms were successfully used to detect concealed EMCs and track their progression in both length and width directions before and after the orthodontic treatment. Obtained results revealed a micro-scale progression of EMCs in both length and width directions after the orthodontic treatment, where the averaged progression of EMCs in length and width were 712.5 and 92.75 µm, respectively. Therefore, high-resolution, non-invasive OCT imaging with developed image processing algorithms can be a fruitful solution to use as a diagnostic tool to monitor the precise coordinates of concealed EMCs throughout the orthodontic treatment.

Strawberry Gel with a Concentration of 83% and 75% as an Extrinsic Stain Remover

Strawberries have many benefits, where the malic acid contained in strawberries acts as a substance that will erode and remove several stains on the surface of teeth, including cleaning extrinsic stains. Gel preparations are widely used in medicines, cosmetics and food products, including toothpaste and teeth whitening agents. The purpose of this study was to determine the effectiveness of strawberry gel with a concentration of 83% and 75% in cleaning teeth with extrinsic stain on academic member of the Health Polytechnic Jakarta I. This study was an Experiment on 30 people who had upper and lower anterior teeth with extrinsic stain as samples. Data collection was done by applying strawberry gel on the surface of the anterior teeth, allowed to stand for 5 minutes, then brushed and rinsed with water. This procedures was done 2 times a day for 5 consecutive days. Changes in extrinsic stain are measured using the Lobene Stain Index which measures the intensity and area of the stain, as well as a combined score of both. The average of combined score with measurements using the Lobene Stain Index for extrinsic stain before being treated with strawberries. Hopefully the score will decreased every day starting from day 1 to day 5 of treatment.

Assessment of efficacy of Kankshi Bhasma Dhantadhavana in extrinsic dental stain an observational study

Chewing tobacco and use of SLT (smokeless tobacco) products cause considerable staining of teeth among users. Discolouration of the teeth is a common complication of tobacco chewing. The stains bind and penetrate the enamel, dentin, root surfaces causing a brown to black discolouration. Tobacco stains cause the enamel to wear away over time. This exposes the dentin (a softer layer of teeth underneath the enamel), which starts to show through, teeth will look increasingly more yellow. These stains can also lead to gum diseases. Artificial dentures, prosthesis is also discoloured by prolonged tobacco chewing. The coarse abrasives in tobacco products when constantly chewed cause abrasion or tooth wear. Chewing tobacco also increases the incidence of dental caries and thereby causes tooth loss. Epidemiology suggests tobacco users have 67 per cent tooth loss compared to non-users. The high content of sweetening and flavouring agents in tobacco products is responsible for tooth decay. To overcome this Kankshi Bhasma Dantadhavan can be an efficient way Kankshi (Potash alum [K2SO4, Al2(SO4)3.24H2O] having antiseptic and antibacterial properties along with that Vruna Ropana, Lekhana, Mukha Rogahara, Dantadadryakara. Danta Paichilyahara, Dantasharkarahara Karma. It is the high time to intervene Ayurveda as remedy in dental stains specific to tobacco chewing.

Stain removal, abrasion and anticaries properties of a novel low abrasion dentifrice containing micro-fibrillated cellulose: in vitro assessments

ObjectivesThis laboratory study assessed the performance of a novel fluoride dentifrice containing micro-fibrillated cellulose (MFC) and entrapped silica. MethodsRemoval of extrinsic stains was assessed using the pellicle cleaning ratio (PCR) method, and radioactive dentin abrasivity (RDA) was measured, to calculate a cleaning efficiency index (CEI). Fluoride efficacy was evaluated using widely used remineralization and fluoride uptake methods. The test product (Protegera™) was compared to common dentifrices (Crest - Cavity Protection™ and ProHealth™, Sensodyne Pronamel™, Arm & Hammer™ Advanced Whitening, Crest ProHealth™, and Colgate Optic White™). ResultsThe PCR for the MFC dentifrice (141) was comparable to three known marketed stain-removing dentifrices (Arm & Hammer™ Advanced Whitening, Crest ProHealth™, and Colgate Optic White™) but it had a significantly lower RDA (88 ± 6) than 5 other products. This gave it the highest CEI of the tested products (2.0). In a 10-day pH cycling study, the fluoride efficacy of the MFC product was comparable to Sensodyne Pronamel and Crest Cavity Protection. The MFC dentifrice was superior for promoting fluoride uptake into incipient enamel lesions compared to the USP reference dentifrice. ConclusionThe MFC dentifrice has low abrasion, but despite this, it is highly effective in removing stained pellicle. It also is an efficacious fluoride source when compared to relevant commercially available fluoride dentifrices with high dentin abrasivity. Clinical significanceThe addition of micro-fibrillated cellulose to a fluoride dentifrice gives a low abrasive product that can effectively remove external stains, and serve as an effective fluoride source. This combination of benefits seems well suited to enamel protection and caries prevention.

Effectiveness of Pineapple (Ananas comosus (L) Merr) Ethanol Extract in Inhibiting Microbes in Biofilm on Acrylic Resin Denture Plates

Artificial acrylic resin tooth plates can get stained and accumulate plaque with various harmful microorganisms. Hence, a natural ingredient-based denture cleanser is required to prevent or remove extrinsic stains and plaque on the dental plates of acrylic resin dentures. The research objective is to demonstrate the efficacy of pinelapplel elxtract in relmoving or minimizing plaqulel on artificial telelth and to asselss thel elffelct of ulsing pinelapplel elxtract as a clelaning agelnt on thel qulality of lifel of delntulrel welarelrs. This relselarch is a laboratory elxpelrimelnt with a post telst only control groulp delsign. Thel stuldy samplels welrel pulrel culltulrel isolatels of Staphylococculs aulreluls, Elntelrococculs facialis, and Strelptococculs gordonii. This relselarch had six groulps, namelly pinelapplel elthanol elxtract 5%, 10%, 25%, 50%, positivel and nelgativel controls by calcullating thel samplel sizel ulsing thel Feldelrelr formulla and geltting relplication for elach groulp 4 timels. Data welrel elxamineld ulsing onel-way ANOVA and Posthoc LSD statistical melthods. According to thel relselarch findings, it can bel claimeld that pinelapplel elthanol elxtract is elffelctivel in prelvelnting thel growth of Staphylococculs aulreluls, Elntelrococculs faelcalis, and Strelptococculs gordonii bactelria. Thel relselarch conclulsion is that pinelapplel elthanol elxtract can elliminatel or minimizel plaqulel-caulsing microbels on artificial acrylic relsin tooth platels to elnhancel thel qulality of lifel of delntulrel welarelrs

POTENTIAL OF VIRGIN COCONUT OIL PASTE AS EXTRINSIC DENTAL STAIN REMOVAL

Introduction: Dental stain is a common condition in society, apart from being an aesthetic problem it can be a predisposing factor for periodontal disease.One type of dental stain is extrinsic dental stain. Virgin Coconut Oil contains lauric acid which has the potential to remove extrinsic dental stains through the foaming mechanism. This research is to determine the effectiveness of Virgin Coconut Oil paste on removing extrinsic dental stain through an in vitro study. Material and Methods: Twenty-five post extraction premolars with extrinsic dental stain on buccal area were divided into 5 groups that is : K1/Control(given artificial saliva), K2(given placebo paste), K3(given 50% Virgin Coconut Oil paste), K4(given 75% Coconut Oil Paste) and K5(given 100% Virgin Coconut Oil Paste). Difference colour intensity (ΔE) before and after treatment were observed using Adobe Photoshop CC 2018 in the CieLAB system. Results and Discussion: Data were analyzed using One Way ANOVA and Post-Hoc Multiple Comparison test. One Way ANOVA test showed that there were significant differences within groups (p&lt;0.05). Post-Hoc Multiple Comparison test showed that there were significant differences between each groups, except for K2 and K3 groups also K4 and K5 groups (P&gt;0.05). Conclusion: Virgin Coconut Oil Paste is effective on removing extrinsic dental stain in vitro

Beyond Surface Beauty: Exploring the Intricate Histopathological Finding in Intrinsic Dentin Discoloration

Dental stains are pigmented deposits that can be intrinsic or extrinsic in origin and are seen on the surface of the teeth. Discoloration of teeth can be due to developmental defects, traumatic injuries, or the intake of several medications. Extrinsic stains create discoloration outside the tooth surface and lay on the surface or in the acquired pellicle, whereas stains within dentin or intrinsic discoloration sometimes come from pulpal or systemic origin. To plan a specific treatment approach and its associated result, it is important to identify the etiologic cause that is creating the stain, in an attempt to provide esthetic treatment for the same. This case report describes the successful management of intrinsic staining of anterior teeth in a 10-year-old girl. The treatment plan included esthetic rehabilitation using composite veneer. The fluoride-releasing composite used provided an acceptable color match and exceptional handling properties and was relatively easy to maintain with its antiplaque effect. This case also represents a unique histopathological finding from ground sections of a retained extracted deciduous tooth.

RELATIONSHIP OF SMOKING HABITS AND COFFEE CONSUMPTION WITH TEETH DISCOLORATION IN ALALAK BANJARMASIN

Background: Teeth discoloration is a problem in dental practice, among others, the occurrence of teeth discoloration in coffee consumers as much as 77.13%, smokers who experience discoloration 76.7%. Based on data from Riskesdas South Kalimantan in 2018, the prevalence of daily smokers in Banjarmasin City is 18.02%. The highest smoking prevalence is in the population aged 30-34 years, which is 30.01%. Teeth discoloration is affected by extrinsic stains through the deposition of chromogenic materials on the teeth surface such as tobacco, tea and coffee. Teeth discoloration can cause discomfort when speaking, smiling and lack of confidence. Purpose: To analyze the relationship between smoking habits and coffee consumption with teeth discoloration in people aged 30-34 years in Alalak Tengah Village. Method: This research is an analytic observational with a cross sectional approach. The sampling technique used is probability sampling technique with a sample size of 87 people. Result: there was a significant relationship between the number of cigarettes and teeth discoloration 0.018 (p&lt;0.05), the relationship between smoking duration and teeth discoloration was 0.006 (p&lt;0.05), a significant relationship between the type of cigarette and teeth discoloration was 0.002 (p&lt;0.05) and vice versa. There is no significant relationship between coffee consumption and duration of drinking coffee with teeth discoloration. Conclusion: Based on the research, there is a relationship between smoking habit and teeth discoloration. Keywords: Cigarettes, Coffee, Teeth Discoloration.

Evaluation of Stain Removal Efficacy and Color Stability of Three Different Dentifrices on Artificially Stained Enamel Surface-An In Vitro Study.

The aim of the present study was to assess the stain removal ability and color stability of three distinct dentifrices on artificially stained enamel surface. This study included 75 intact, healthy premolars free of dental caries that were extracted during orthodontic therapy. The samples were allowed to dry for 6 hours after being submerged in the prepared tea solution for roughly 18 hours every day. Then this procedure was repeated for seven successive days. All samples were randomly divided into three experimental groups with 25 samples in each group. Group I: control dentifrice, group II: dentifrice containing hydrogen peroxide, group III: dentifrice containing papain and bromelain. A specially designed toothbrushing simulator was used to brush every sample in the relevant group. Using a spectrophotometer and a measurement program, color measurement was evaluated after staining process after 4 weeks and 8 weeks of teeth cleaning. Using a profilometer, the surface roughness values (Ra) were assessed. After 8 weeks of brushing of stained samples, the color stability was better in dentifrice containing hydrogen peroxide (1.14 ± 0.11) followed by dentifrice containing papain and bromelain (1.22 ± 0.08) and control group (1.30 ± 0.09). And after 8 weeks of brushing of stained samples, the surface roughness was more in dentifrice containing hydrogen peroxide (0.237 ± 0.02) followed by dentifrice containing papain and bromelain (0.229 ± 0.13) and control group (0.207 ± 0.05). The present study concluded that the dentifrice containing hydrogen peroxide showed a superior whitening effect on the stained enamel surface than dentifrice containing papain and bromelain and control dentifrice. The development of various dentifrice products has been greatly aided by the increased demand for an improved esthetic appearance. Teeth's natural color and any external stains that could accumulate on the tooth surface combine to determine a tooth's color. Additionally, the use of whitening dental pastes to remove external stains has grown in favor. With the development of these whitening toothpastes, dentifrices' ability to lessen or eliminate extrinsic dental stains has increased. How to cite this article: Mishra D, Kamath DG, Alagla M, et al. Evaluation of Stain Removal Efficacy and Color Stability of Three Different Dentifrices on Artificially Stained Enamel Surface-An In Vitro Study. J Contemp Dent Pract 2024;25(1):68-71.

Combining single-molecule and expansion microscopy in fission yeast to visualize protein structures at the nanostructural level.

In this work, we have developed an expansion microscopy (ExM) protocol that combines ExM with photoactivated localization microscopy (ExPALM) for yeast cell imaging, and report a robust protocol for single-molecule and expansion microscopy of fission yeast, abbreviated as SExY. Our optimized SExY protocol retains about 50% of the fluorescent protein signal, doubling the amount obtained compared to the original protein retention ExM (proExM) protocol. It allows for a fivefold, highly isotropic expansion of fission yeast cells, which we carefully controlled while optimizing protein yield. We demonstrate the SExY method on several exemplary molecular targets and explicitly introduce low-abundant protein targets (e.g. nuclear proteins such as cbp1 and mis16, and the centromere-specific histone protein cnp1). The SExY protocol optimizations increasing protein yield could be beneficial for many studies, when targeting low abundance proteins, or for studies that rely on genetic labelling for various reasons (e.g. for proteins that cannot be easily targeted by extrinsic staining or in case artefacts introduced by unspecific staining interfere with data quality).

A novel air-polishing powder from natural eggshell.

This study compares the ability of extrinsic stain removal and surface roughness changes on tooth surfaces after using two different types of dental air polishing powder: Sodium bicarbonate and novel eggshell powder. For the study of extrinsic stain removal, twenty bovine teeth were soaked in coffee for extrinsic stain formation. Group 1 and Group 2 were polished with sodium bicarbonate powder and novel eggshell powder, respectively. The acquired stains of teeth were recorded as baseline, and color changes after cleaning with two different powders were also measured by colorimeter. Sixteen samples from eight human posterior teeth were used for the surface roughness test. Surface roughness values (Sa) of two groups (sodium bicarbonate and novel eggshell powder) were measured by a contact-type profilometer before and after polishing with two types of powders. The data showed that the average ΔE* value of the sodium bicarbonate group was higher than that of the novel eggshell powder group (P < 0.05). The average ΔSa value of the sodium bicarbonate group was higher than that of the novel eggshell powder group (P < 0.05). Sodium bicarbonate powder showed higher stain removal ability and surface roughness changes than the novel eggshell powder.

Esthetic rehabilitation of a patient with moderate fluorosis: a digital workflow

Dental fluorosis is considered as a worldwide dental health problem. Its prevalence is increasing in different parts of the world. It is described as a disorder of enamel development caused by chronic and excessive exposure to high concentrations of fluoride during the formation of enamel, which could be responsible for the hypermineralization of enamel increasing its porosity. It is clinically identified as white lines covering all or a part of the enamel surface. Posteruptively, these subsurface porosities may attract various extrinsic stains and /or bacteria and change the color of the affected enamel. In some cases, occlusal trauma may cause its detachment. The therapeutic management of dental fluorosis includes bleaching, microabrasion, veneering and crowning. The choice of the appropriate alternatives is closely linked to damages within the enamel matrix. Thylstrup-Fejerskov categorized these damages with severity scores based on their histological features. Mild-to-moderate fluorosis are often managed with bleaching and/or microabrasion, while severe fluorosis, is generally treated by veneering and crowning. The clinical case describes the treatment of discolored teeth with veneers using lithium disilicate-reinforced glass-ceramic material and highlights the different guidelines to optimize veneer bonding on fluorosis teeth.

Non-invasive vital teeth whitening for enhanced facial esthetic: A case report

For ages, a bright white smile symbolizes beauty, wellness, and vitality. The translucency and thickness of the enamel, hue of the underlying dentin, vitality, and color of the pulp all contribute to the pigmentation of teeth. Color changes in the crown can be due to physiologic or pathologic and endogenous or exogenous factors. Extrinsic or intrinsic stains are the most common causes of tooth discoloration. Discoloration, especially in the anterior teeth, seriously impairs esthetics and might make a patient feel less confident. In the treatment of discolored teeth, various invasive and non-invasive options, such as veneers and bleaching, are available, respectively. However, the urge for esthetic dentistry, particularly teeth whitening, has grown significantly in recent decades. As compared to invasive treatment options, non-invasive methods like bleaching (teeth whitening) are the most conservative choice for stained teeth and are preferred in situations where tooth structure is intact. Teeth whitening has developed into a well-liked and commonly requested dental procedure as a result of the public need for a brighter smile and enhanced looks. This paper aims to describe a case of vital, discolored anterior teeth due to fluorosis lightened using 35% hydrogen peroxide. A 19-year-old female patient reported to the department with discolored upper front teeth. After the procedure was completed, a pleasing esthetic result was achieved.

Longevity of extrinsic stains on monolithic zirconia restorations: An in vitro study

Three-mol% yttria-stabilized tetragonal zirconia polycrystal (3Y-TZP) has been commonly used for fixed prosthodontic restorations. The opacity of 3Y-TZP may be masked with external staining, although the longevity of extrinsic stains applied to monolithic zirconia is unclear. The purpose of this in vitro study was to analyze the color and surface roughness of extrinsically stained zirconia specimens after thermocycling and toothbrushing. Monolithic Ø12.5×1.25-mm zirconia disks were milled from 3Y-TZP blocks, sintered according to manufacturer instructions, and then divided into 3 groups (C, J, and O; n=16) for application of stain and glaze. All specimens underwent 10 000 thermocycles in distilled water before being further divided into 2 dentifrice groups (n=8): normal grit, low relative dentin abrasivity (RDA) (Subgroup N) and abrasive grit, high RDA (Subgroup A). Specimens were brushed in a multistation brushing machine under 1.47N of force using a 5:8 toothpaste and distilled water slurry for 10 000 cycles with a straight (American Dental Association Standard) toothbrush to simulate 1 year of toothbrushing. Color and surface roughness measurements were obtained at 3 time points: baseline, after thermocycling, and after brushing. A 2-way repeated measures ANOVA was used to independently assess changes in color and surface roughness with respect to thermocycling and brushing (α=.05). Group J displayed no significant change in color for either dentifrice system (P>.05). However, a significant change in surface roughness was observed for both dentifrice subgroups (P<.001). Group C specimens displayed significant changes in color (P<.001) and surface roughness (P<.001) for both dentifrice systems. Group O specimens displayed significant changes in color (P<.025) for both dentifrice systems and significant changes in surface roughness (P<.004) for subgroup A, but no significant changes for subgroup N (P=.075). Artificial aging of monolithic zirconia resulted in changes in color and surface roughness that did not surpass the thresholds for perceptibility and acceptability. This study failed to establish durability limits for extrinsic stains applied to 3Y-TZP.

Evaluation of the antibacterial activity of cinnamon essential oil and its individual compounds on Aggregatibacter actinomycetemcomitans isolated from black extrinsic tooth stain: an in vitro study.

Black extrinsic tooth stain (BETS) is a health challenge that commonly affects children. Aggregatibacter actinomycetemcomitans (Aa) presents in higher prevalence within the polymicrobial community of BETS. In this study, the anti-planktonic and anti-sessile activities of cinnamon essential oil (CEO) and its individual compounds against Aa were evaluated. The preventive effect of CEO and its active substances on BETS formation was also studied in vitro. Aa was isolated from a preschool child with BETS and was identified based on the morphological characteristics, MALDI-TOF mass spectroscopy and 16S rRNA sequencing. The effect of CEO and its individual compounds on the growth kinetics of planktonic and sessile Aa cells as well as their antibacterial efficacy and their rate of bacterial killing were examined. The preventive effect of CEO and its active substances on the formation of BETS was evaluated using an ex vivo model. The data were analysed using one-way analysis of variance (ANOVA) and the significance level was set at p < 0.05. Out of eight individual compounds of CEO, only eugenol, cinnamaldehyde and α-methyl cinnamaldehyde showed anti-Aa activities. The values of the minimum inhibitory concentrations (MICs) were in the following order: CEO (421.5mg/ml) > α-methyl cinnamaldehyde (26.37mg/ml) > cinnamaldehyde (0.209mg/ml) > eugenol (0.052mg/ml). CEO, eugenol, cinnamaldehyde and α-methyl cinnamaldehyde, respectively, exhibited two-, four-, four- and eightfold increase of sessile MIC compared to their planktonic MIC. The growth kinetics of both planktonic and sessile Aa in the presence of CEO, eugenol, cinnamaldehyde and α-methyl cinnamaldehyde revealed a complete inhibition at the MICs and 5.3%-37.4% biofilm inhibition at sub-MICs. The time-killing study demonstrated that CEO, eugenol and cinnamaldehyde were capable of reducing the survival rate of both planktonic and sessile Aa cells after 15-20 and 25-30min, respectively. However, α-methyl cinnamaldehyde showed a superior anti-planktonic to anti-biofilm activity. The daily incorporation of CEO, eugenol and cinnamaldehyde at their MICs for 14days totally prevented the formation of BETS in the ex vivo model; however, in the case of α-methyl cinnamaldehyde, BETS was visually detectable after 10days. CEO and its individual compounds have marked antibacterial activity against Aa. The effective results against planktonic and sessile Aa within reasonable time indicate that they can be used to prevent BETS.

Effect of Finishing Protocols on the Surface Roughness and Fatigue Strength of a High-Translucent Zirconia.

In case of need for esthetical improvement of zirconia restorations, an individualization using extrinsic staining can be applied. This study aimed to evaluate the surface roughness and fatigue strength (survival) of high-translucency zirconia (3Y-TZP, YZ®HT, Vita Zanhfabrik) with extrinsic characterization and/or glaze. Sixty (60) zirconia discs (12 × 1.2 mm) were obtained, sintered, and randomly distributed among three groups (n = 20) according to the surface finishing protocol: C (control), C + G (extrinsic characterization followed by a glaze layer), and G (glaze layer). The surface roughness (Ra) was analyzed with a contact profilometer. Subsequently, the specimens were subjected to a fatigue load profile starting at 120 N during 20,000 cycles at 4 Hz frequency, with a 5% increase at each step until failure. The failed specimens were evaluated under a stereomicroscope. Surface roughness analysis was evaluated by using one-way ANOVA and post hoc Tukey tests (95%); while fatigue survival probability was analyzed with Kaplan-Meier and Mantel-Cox (log- rank, 95%). One-way ANOVA revealed that surface roughness was affected by the finishing protocol, where C + G showed the highest mean value (0.46 ± 0.18 µm)A followed by G (0.30 ± 0.10 µm)B, and C (0.19 ± 0.02 µm)C. While for fatigue strength, the G protocol presented a higher mean value (243.00, and 222.36-263.63)A, followed by C + G (192.75 and 186.61-198.88)B and C (172.50 and 159.43-185.56)C. Surface finishing protocols modify the surface roughness and fatigue strength of high-translucent zirconia. Regardless of the surface roughness, both glazing protocols improved the ceramic fatigue strength, favoring the restoration's long-term survival.