Effects of erosion and abrasion on resin-matrix ceramic CAD/CAM materials: An in vitro investigation.

The aim of the study was to evaluate the effects of erosion and abrasion on resin-matrix ceramic CAD/CAM materials [CERASMART (GC); VITA ENAMIC (VITA Zahnfabrik); Lava Ultimate (3 M)] in comparison to feldspar ceramic (VITABLOCS Mark II, VITA Zahnfabrik) and resin composite materials (ceram.x universal, Dentsply Sirona). Daily brushing and acid exposure were simulated using a brushing apparatus and a solution of 0.5 vol% citric acid. Microhardness, surface roughness, and substance loss were measured at baseline and after simulation of 1 and 3 years of function. All materials showed a decrease in microhardness after 3 years and an increase in surface roughness (Ra) after 1 and 3 years. The Ra increase was statistically significantly lower for the resin-matrix ceramics than for feldspar ceramic and similar to composite material. After 3 years, only feldspar ceramic showed no significant substance loss. In conclusion, resin-matrix ceramics demonstrate reduced roughening compared to feldspar ceramics, potentially improving restoration longevity by preventing plaque buildup, but differences in abrasion resistance suggest the need for further material-specific research. Future research should aim to replicate clinical conditions closely and to transition to in vivo trials.

Impact of air-polishing with erythritol on exposed root dentin: A randomized clinical trial.

INTRODUCTION: The effects of air-polishing on exposed root dentin surfaces are largely unknown, as there are only few studies which show heterogeneous results. Thus, this study was to investigate roughness changes of exposed dentin surfaces after air-polishing and the influence of subsequent polishing with cup and paste. METHODS: Totally 54 teeth with exposed root dentin surfaces were treated using a split-mouth design by either air-polishing with erythritol and a rubber cup with polishing paste on the test side, or rubber cup and paste alone. Teeth were finally cleaned using a sonic tooth brush. Impressions were taken at relevant time points and replicated using epoxy resin. The resulting casts were profilometrically analysed to obtain the average surface roughness (sRa) and maximum peak-to-valley height (sRz), which are given as the mean ± standard deviation in µm. RESULTS: After air-polishing, in comparison to the baseline, there was a slight but significant increase in sRa (0.168 ± 0.143, p < 0.001), but sRz did not change (-0.471 ± 4.857, p = 0.936). Subsequent polishing with cup and paste and cleaning with a sonic toothbrush did not reduce the surface roughness (sonic toothbrush-air-polishing, sRa -0.044 ± 0.081, p = 0.218; sRz -0.551 ± 3.563, p = 0.903). CONCLUSION: The use of erythritol led to a slight increase in the roughness of the dentin surface, which was not reduced by polishing with a cup and paste. Polishing paste did not seem to conceal surface irregularities.

Optimizing the use of low-frequency ultrasound for bacterial detachment of in vivo biofilms in dental research-a methodological study.

OBJECTIVES: Low-frequency, low-intensity ultrasound is commonly utilized in various dental research fields to remove biofilms from surfaces, but no clear recommendation exists in dental studies so far. Therefore, this study aims to optimize the sonication procedure for the dental field to efficiently detach bacteria while preserving viability. MATERIALS AND METHODS: Initial biofilm was formed in vivo on bovine enamel slabs (n = 6) which were worn by four healthy participants for 4 h and 24 h. The enamel slabs covered with biofilm were then ultrasonicated ex vivo for various time periods (0, 1, 2, 4, 6 min). Colony-forming units were determined for quantification, and bacteria were identified using MALDI-TOF. Scanning electron microscopic images were taken to also examine the efficiency of ultrasonications for different time periods. RESULTS: Ultrasonication for 1 min resulted in the highest bacterial counts, with at least 4.5-fold number compared to the non-sonicated control (p < 0.05). Most bacteria were detached within the first 2 min of sonication, but there were still bacteria detached afterwards, although significantly fewer (p < 0.0001). The highest bacterial diversity was observed after 1 and 2 min of sonication (p < 0.03). Longer sonication periods negatively affected bacterial counts of anaerobes, Gram-negative bacteria, and bacilli. Scanning electron microscopic images demonstrated the ability of ultrasound to desorb microorganisms, as well as revealing cell damage and remaining bacteria. CONCLUSIONS: With the use of low-frequency, low-intensity ultrasound, significantly higher bacterial counts and diversity can be reached. A shorter sonication time of 1 min shows the best results overall. CLINICAL RELEVANCE: This standardization is recommended to study initial oral biofilms aged up to 24 h to maximize the outcome of experiments and lead to better comparability of studies.

Improving the microbial sampling and analysis of secondary infected root canals by passive ultrasonic irrigation.

OBJECTIVE: The persistence of pathogenic microorganisms in root canals is the most common reason for the failure of root canal treatment and the necessity of a root filling treatment, which results in an uncertain prognosis due to technical complexity and the variety of highly adaptable microorganisms. This study evaluated the effect of passive ultrasonic irrigation (PUI) on the outcome of the microbial analysis of root canal-treated teeth with persistent or recurrent apical inflammation in vivo. MATERIALS AND METHODS: Sample collection was performed after root filling removal (sample S1, control group) and after PUI with NaCl (sample S2) using sterile paper points. In total, 19 samples were obtained. Quantification was performed by means of serial dilution of the samples. Subcultivated pure cultures were identified using MALDI-TOF MS complemented by the Vitek-2-System or PCR, followed by sequencing of the 16S rRNA gene. The results of the samples (S1 and S2) were evaluated regarding their bacterial count and composition. RESULTS: The total count of bacteria and the number of aerobic/facultative anaerobic microorganisms significantly increased in the S2-samples after application of PUI. The number of obligate anaerobic microorganisms showed an increase after PUI, although it was not significant. We detected 12 different aerobic/facultative anaerobic microorganisms before PUI, and in 21 cases after PUI. Two different obligate anaerobic microorganisms were found in S1 samples compared to nine different species in S2 samples. CONCLUSIONS: PUI is a powerful method for detaching bacteria in infected root canals and enables a more precise analysis of the etiology of persistent endodontic infections. CLINICAL RELEVANCE: This study indicates that PUI exerts a positive cleansing effect and adds to the accessibility of microorganisms during the application of bactericidal rinsing solution in root canal treatments.

The antimicrobial effect of Rosmarinus officinalis extracts on oral initial adhesion ex vivo.

OBJECTIVE: In the last few decades, there has been a growing worldwide interest in the use of plant extracts for the prevention of oral diseases. The main focus of this interest lies in the identification and isolation of substances that limit the formation of microbial biofilm which plays a major role in the development of caries, periodontitis, and peri-implantitis. In this clinical ex vivo study, we investigated the antimicrobial effects of Rosmarinus officinalis extract against oral microorganisms within in situ initial oral biofilms. MATERIALS AND METHODS: Initial in situ biofilm samples (2 h) from six healthy volunteers were treated ex vivo with R. officinalis extract at concentrations of 20 mg/ml and 30 mg/ml. The number of viable bacterial cells was determined by counting the colony-forming units. All surviving bacteria were isolated in pure cultures and identified using MALDI-TOF and biochemical testing procedures. Additionally, live/dead staining in combination with epifluorescence microscopy was used for visualizing the antimicrobial effects in the initial biofilms. RESULTS: The number of colony-forming units in the R. officinalis-treated biofilms was significantly lower than in the untreated controls (p < 0.001). The reduction range of log10 was 1.64-2.78 and 2.41-3.23 for aerobic and anaerobic bacteria, respectively. Regarding the bacterial composition, large intra- and interindividual variability were observed. Except for Campylobacter spp., the average amount of all bacterial taxa was lower after treatment with R. officinalis than in the untreated biofilms. A total of 49 different species were detected in the untreated biofilms, while only 11 bacterial species were detected in the R. officinalis-treated biofilms. Live/dead staining confirmed that the R. officinalis-treated biofilms had significantly lower numbers of surviving bacteria than the untreated biofilms. CONCLUSIONS: The treatment with R. officinalis extract has a significant potential to eliminate microbial oral initial biofilms. CLINICAL RELEVANCE: The results of this study encourage the use of R. officinalis extracts in biofilm control and thus in the treatment of caries and periodontitis as a herbal adjuvant to synthetic substances.

Colonization of Helicobacter pylori in the oral cavity - an endless controversy?

Helicobacter pylori is associated with chronic gastritis, gastric or duodenal ulcers, and gastric cancer. Since the oral cavity is the entry port and the first component of the gastrointestinal system, the oral cavity has been discussed as a potential reservoir of H. pylori. Accordingly, a potential oral-oral transmission route of H. pylori raises the question concerning whether close contact such as kissing or sharing a meal can cause the transmission of H. pylori. Therefore, this topic has been investigated in many studies, applying different techniques for detection of H. pylori from oral samples, i.e. molecular techniques, immunological or biochemical methods and traditional culture techniques. While molecular, immunological or biochemical methods usually yield high detection rates, there is no definitive evidence that H. pylori has ever been isolated from the oral cavity. The specificity of those methods may be limited due to potential cross-reactivity, especially with H. pylori-like microorganisms such as Campylobacter spp. Furthermore, the influence of gastroesophageal reflux has not been investigated so far. This review aims to summarize and critically discuss previous studies investigating the potential colonization of H. pylori in the oral cavity and suggest novel research directions for targeting this critical research question.

In vivo and in vitro analysis in a rat model using zoledronate and alendronate medication: microbiological and scanning electron microscopy findings on peri-implant rat tissue.

BACKGROUND: The aim of the present study was to assess the development of bacterial deposits and morphological parameters around dental zirconia and titanium implants compared with natural teeth during systemic bisphosphonate medication. MATERIALS AND METHODS: Fifty-four rats were randomly allocated into one control group and two experimental groups (drug application of zoledronic and alendronic acid), with 18 animals in each group. After 4 weeks of drug delivery, either a zirconia or a titanium implant was immediately inserted. Microbiological analysis conducted 1 week, 8 weeks, and 12 weeks after surgery included total bacterial count and composition measurements. Samples were analyzed in a scanning electron microscope (SEM) equipped with energy-dispersive X-ray spectroscopy (EDX). Bone cell morphology was analyzed by transmission electron microscopy (TEM). RESULTS: One week after surgery, titanium and zirconia implants of the alendronic acid and control group showed a significantly higher bacterial count when compared to natural teeth in rats with zoledronic acid administration (p < 0.01). Less significant differences were recorded after 3 months, at which time no inter-material differences were evaluated (p > 0.05). I n the control group, TEM analysis showed that the osteoblasts had a strongly developed endoplasmic reticulum. In contrast, the endoplasmic reticulum of the osteoblasts in drug-treated animals was significantly less developed, indicating less activity. CONCLUSIONS: Within the limits of this study, neither implant material was superior to the other at 3-month follow-up. With regard to the treatment and complications of patients with bisphosphonates, the implant material should not be an influencing factor. Bisphosphonates can be used in the rat model to reduce not only the activity of osteoclasts but also osteoblasts of the peri-implant bone.

Cetylpyridinium Chloride: Mechanism of Action, Antimicrobial Efficacy in Biofilms, and Potential Risks of Resistance.

Antimicrobial resistance is a serious issue for public health care all over the world. While resistance toward antibiotics has attracted strong interest among researchers and the general public over the last 2 decades, the directly related problem of resistance toward antiseptics and biocides has been somewhat left untended. In the field of dentistry, antiseptics are routinely used in professional care, but they are also included in lots of oral care products such as mouthwashes or dentifrices, which are easily available for consumers over-the-counter. Despite this fact, there is little awareness among the dental community about potential risks of the widespread, unreflected, and potentially even needless use of antiseptics in oral care. Cetylpyridinium chloride (CPC), a quaternary ammonium compound, which was first described in 1939, is one of the most commonly used antiseptics in oral care products and included in a wide range of over-the-counter products such as mouthwashes and dentifrices. The aim of the present review is to summarize the current literature on CPC, particularly focusing on its mechanism of action, its antimicrobial efficacy toward biofilms, and on potential risks of resistance toward this antiseptic as well as underlying mechanisms. Furthermore, this work aims to raise awareness among the dental community about the risk of resistance toward antiseptics in general.

Long-Term Fluctuation of Oral Biofilm Microbiota following Different Dietary Phases.

Caries development is associated with shifts in the oral biofilm microbiota and primarily linked to frequent simple carbohydrate consumption. Different nutritional ingredients can either promote or prevent caries development. To investigate the effects of selected ingredients on the oral biofilm microbiota in situ, 11 study participants underwent 3-month-long dietary phases with intake of a regular diet (PI), additional frequent sucrose (PII), milk and yoghurt (PIII), and a diet rich in dietary fiber (PIV) and then returned to their regular diet (PV). Oral biofilm was sampled and analyzed applying 16S rRNA Illumina MiSeq sequencing. Additionally, the effect on the enamel was analyzed by measuring enamel surface roughness with laser scanning microscopy. The beta-diversity results showed that the microbiota in all the following phases differed significantly from PI and that the microbial community in PII was significantly different from all other phases. The abundance of the genus Streptococcus fluctuated over the course of the five phases, with a significant increase in PII (P = 0.01), decreasing in PIII and PIV (PIII and PIV versus PII: P < 0.00001) and increasing again toward PV. Other taxa showed various fluctuations of their abundances, with PV returning approximately to the levels of PI. In conclusion, while elevated sucrose consumption favored caries-promoting non-mutans streptococci, frequent milk and yoghurt intake caused a significant decrease in the abundance of these microbial taxa and in addition reduced enamel surface roughness. These results indicate that modulations of the oral biofilm microbiota can be attained even in adults through dietary changes and corresponding recommendations can be made for the prevention of caries development.IMPORTANCE Caries affects a large proportion of the population worldwide, resulting in high treatment costs. Its etiology can be ascribed to shifts of the microbiota in dental biofilms primarily driven by dietary factors. It is unclear how diet affects the microbial community of plaque biofilm in situ and whether it can be modulated to help prevent caries development. To address these issues, we analyzed changes of the in situ plaque microbiota following 3-month-long dietary changes involving elevated sucrose, dairy, and dietary fiber consumption over a period of 15 months. Applying high-throughput sequencing, we found non-mutans streptococci, a taxonomic group involved in the beginning stages toward microbial dysbiosis, in decreased abundance with elevated dairy and dietary fiber intake. Through analysis of the enamel surface roughness, these effects were confirmed. Therefore, correspondent dietary measures can be recommended for children as well as adults for caries prevention.

In vitro evaluation of the cariogenic potential of rebaudioside A compared to sucrose and xylitol.

OBJECTIVES: The aim of the present study was to evaluate the growth and acid synthesis of cariogenic pathogens in vitro when rebaudioside A was the sole source of carbon, compared to sucrose, xylitol, and a commercial sweetener containing rebaudioside A. MATERIALS AND METHODS: First, sucrose or sugar substitutes were added to human saliva and the pH was measured over 10 h. Subsequently, the growth and acid synthesis efficiency of Streptococcus mutans, Streptococcus sobrinus, Streptococcus oralis, Lactobacillus rhamnosus, Lactobacillus paracasei, and Candida albicans were investigated: after adding them to minimal culture media containing only one of the carbon sources, the optical density and pH were determined over 10 h. RESULTS: A significant pH drop only occurred in the sucrose group of human saliva whereas no differences were found between the sugar substitute groups. The individual strains of caries pathogens showed significantly lower growth rates and less acid synthesis in the sugar replacement groups, in comparison to sucrose. However, these groups also showed bacterial growth and a decline in pH. CONCLUSION: Xylitol appeared to be superior to rebaudioside A regarding the inhibition of mutans streptococci. The results for the remaining microorganisms indicate that rebaudioside A causes a similar or lower acid synthesis than xylitol. As saliva contains buffer systems, the metabolism of rebaudioside A did not seem to shift the equilibrium to demineralization. CLINICAL RELEVANCE: Rebaudioside A may not be suitable as a targeted Streptococcus mutans treatment, but it could contribute to a reduction of caries risk as a replacement for sucrose.

Clinical management of fusion in primary mandibular incisors: a systematic literature review.

Objective: Dental anomalies occurring in deciduous teeth can affect the eruption of the permanent dentition and the occlusion stability. The occurrence of dental anomalies such as double teeth during the primary dentition in the daily practice might be frequent. The study aimed to qualitatively summarize the therapeutic management of double teeth in primary incisors.Material and Methods: A systematic review regarding the therapy of primary fused incisors in the mandible was performed and the obtained data were assessed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The following electronic databases were screened from 1st January, 1996 until 30th July, 2019: PubMed, Scopus, EBSCO and the archives of paediatric dental journals. The search terms were grouped in anatomic entity: (tooth OR teeth OR incisor), pathological condition: (fused OR fusion OR geminated OR double), intervention: (treatment OR intervention OR therapy OR prevention OR control OR management OR restoration), observed parameters: (primary dentition OR primary tooth OR primary teeth).Results: Ten articles met all inclusion criteria. The data disclosed the occurrence of double teeth in mandibular incisors. The main management of this clinical condition is either preventive or surgical involving the extraction of fused teeth, based on the deciduous nature of the teeth, the degree of caries and malocclusion development risk.Conclusion: An early diagnosis of dental anomalies is fundamental for the application of proper preventive strategies to avoid a potential malocclusion in permanent dentition and to maintain these teeth sound and caries-free until the eruption of the permanent dentition.

The influence of an anti-inflammatory diet on gingivitis. A randomized controlled trial.

AIM: Aim of this study was to investigate the influence of an anti-inflammatory diet on different parameters in patients with gingivitis. MATERIALS AND METHODS: Thirty patients were randomly allocated to an experimental and a control group stratified by their plaque values. The experimental group had to change to a diet low in processed carbohydrates and animal proteins, and rich in omega-3 fatty acids, vitamin C, vitamin D, antioxidants, plant nitrates and fibres for 4 weeks. The control group did not change their diet. Both groups suspended interdental cleaning. Periodontal parameters were assessed by a blinded dentist. Serological and subgingival plaque samples were taken at baseline and end. RESULTS: While there were no differences regarding the plaque values, the experimental group showed a significant reduction in gingival bleeding (GI Baseline: 1.04 ± 0.21, GI End: 0.61 ± 0.29, p < 0.05), a significant increase in Vitamin D values and a significant weight loss. There were no inter-group differences regarding the inflammatory serological parameters, the serological omega fatty acids, nor the subgingival microbiome composition. CONCLUSION: The evaluated diet could significantly reduce gingivitis in a clinically relevant range, while serological inflammatory parameters and the subgingival microbiome seem to be unaffected in this study duration. (German Clinical Trials Register; DRKS00009888).

Compounds from Olea europaea and Pistacia lentiscus inhibit oral microbial growth.

BACKGROUND: In view of the increasing antibiotic resistance, the introduction of natural anti-infective agents has brought a new era in the treatment of bacterially derived oral diseases. METHODS: The aim of this study was to investigate the antimicrobial potential of five natural constituents of Olea europaea (oleuropein, maslinic acid, hydroxytyrosol, oleocanthal, oleacein) and three compounds of Pistacia lentiscus (24Z-isomasticadienolic acid, oleanolic acid, oleanonic aldehyde) against ten representative oral bacterial species and a Candida albicans strain. After the isolation and quality control of natural compounds, the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) assay were performed. RESULTS: Among all O. europaea-derived constituents, maslinic acid was the most active (MIC = 4.9-312 µg mL- 1, MBC = 9.8-25 µg mL- 1) one against oral streptococci and anaerobic pathogenic bacteria (Porphyromonas gingivalis, Fusobacterium nucleatum, Parvimonas micra), while oleuropein, hydroxytyrosol, oleocanthal and oleacein showed milder, yet significant effects against P. gingivalis and F. nucleatum. Among all P. lentiscus compounds, oleanolic acid was the most effective one against almost all microorganisms with MIC values ranging from 9.8 µg mL- 1 (P. gingivalis) to 625 µg mL- 1 (F. nucleatum, P. micra). In the presence of 24Z-isomasticadienolic acid, a mean inhibitory concentration range of 2.4 µg mL- 1 to 625 µg mL- 1 was observed for strict anaerobia. The MIC value for 24Z-isomasticadienolic acid was estimated between 39 µg mL- 1 (Streptococcus sobrinus, Streptococcus oralis) and 78 µg mL- 1 (Streptococcus mutans). All tested compounds showed no effects against Prevotella intermedia. CONCLUSIONS: Overall, maslinic acid and oleanolic acid exerted the most significant inhibitory activity against the tested oral pathogens, especially streptococci and anaerobic oral microorganisms.

Guided endodontic access of a calcified mandibular central incisor using a software-based three-dimensional treatment plan.

This case report describes the digital and clinical workflow of a guided endodontic access approach in a mandibular central incisor with pulp canal calcification (PCC). The access to the remaining pulp space was planned virtually using cone beam computed tomography (CBCT) and the Sicat Endo software (Sicat, Bonn, Germany). Sicat produced the corresponding Accessguide after matching a digitized cast model and the virtual treatment plan. The clinical access was prepared using a carbide bur with a diameter of 1.2 mm. After the root canal was localized successfully, it was disinfected chemomechanically, dried, and obturated using a warm vertical compaction technique.

Antimicrobial photodynamic therapy - what we know and what we don't.

Considering increasing number of pathogens resistant towards commonly used antibiotics as well as antiseptics, there is a pressing need for antimicrobial approaches that are capable of inactivating pathogens efficiently without the risk of inducing resistances. In this regard, an alternative approach is the antimicrobial photodynamic therapy (aPDT). The antimicrobial effect of aPDT is based on the principle that visible light activates a per se non-toxic molecule, the so-called photosensitizer (PS), resulting in generation of reactive oxygen species that kill bacteria unselectively via an oxidative burst. During the last 10-20 years, there has been extensive in vitro research on novel PS as well as light sources, which is now to be translated into clinics. In this review, we aim to provide an overview about the history of aPDT, its fundamental photochemical and photophysical mechanisms as well as photosensitizers and light sources that are currently applied for aPDT in vitro. Furthermore, the potential of resistances towards aPDT is extensively discussed and implications for proper comparison of in vitro studies regarding aPDT as well as for potential application fields in clinical practice are given. Overall, this review shall provide an outlook on future research directions needed for successful translation of promising in vitro results in aPDT towards clinical practice.

Antibiotic Resistance Genes and Antibiotic Susceptibility of Oral Enterococcus faecalis Isolates Compared to Isolates from Hospitalized Patients and Food.

Enterococcus faecalis, a commensal of the intestinal tract of humans and animals is of great significance as leading opportunistic pathogen, and also prevalent in oral diseases, such as endodontic infections, as well as the healthy oral cavity. To investigate the potential of oral E. faecalis to constitute a reservoir of antibiotic resistance, isolates from supragingival plaque/saliva and from endodontic infections were screened regarding their resistance to selected antibiotics in comparison to nosocomial and food isolates.70 E. faecalis isolates were analyzed with PCR regarding their equipment with the resistance genes tetM, tetO, ermB, ermC, vanA, vanB and blaTEM. Additionally, they were tested for their phenotypic resistance to doxycycline, azithromycin, rifampicin, amoxicillin and streptomycin using the Etest.High percentages of the plaque/saliva, nosocomial and food isolates were resistant to doxycycline and azithromycin, particularly plaque/saliva isolates (81%) and nosocomial isolates (73.3%) showed resistance to doxycycline, significantly more than among the food and endodontic isolates. Rifampicin resistance was widespread among isolates from plaque/saliva (52.4%), endodontic infections (50%) and nosocomial infections (40%); all isolates were susceptible to amoxicillin and all oral isolates to high-level streptomycin. TetM genes were detected in the majority of all isolates and ermB genes were present in many nosocomial and plaque/saliva isolates. Thirty percent of the endodontic isolates and 53% of the nosocomial isolates were equipped with blaTEM genes.The results suggest that the oral cavity can harbor E. faecalis strains with multiple resistances against different antibiotics and thus be regarded as a potential source of resistance traits.

Activity of preparations from Spilanthes oleracea, propolis, Nigella sativa, and black garlic on different microorganisms involved in oral diseases and on total human salivary bacteria: A pilot study.

Due to continuous rise in antibiotic resistance, there is a need for alternative treatment options to reduce the levels of oral pathogens for the maintenance of oral as well as overall health. The aim of this study was to evaluate the in vitro antibacterial potential of tinctures of Spilanthes oleracea and propolis, Nigella seed oil, and an ethanolic extract of black garlic on microorganisms involved in oral diseases. Both the minimum inhibitory concentration assay and the minimum bactericidal/fungicidal concentration assay were used in this study. Inhibition effects against total human salivary bacteria were also determined. Our results show that all of the preparations tested had potent antimicrobial activities. When measured 10 min after exposure, even low concentrations of the propolis tincture were found to have killed more than 99% of salivary bacteria, whereas Spilanthes tincture and black garlic extract killed more than 90% and Nigella seed oil more than 60% of the pathogens. This suggests that all preparations are promising candidates for the use in oral health care products and that all have the potential to control biofilm associated infections.

The effect of long-term use of tooth bleaching products on the human enamel surface.

The aim of this in vitro study was to evaluate the long-term effect of bleaching on human enamel. Four groups of enamel specimens were prepared (n = 20): group 1: bleaching with Opalescence Boost [40% hydrogen peroxide (H2O2), 3 × 20 min/week]; group 2: control group (the specimens were stored in human saliva); group 3: beaching with Vivastyle Paint on Plus (6% H2O2, 2 × 10 min/day), and group 4: bleaching with Opalescence PF 16% [16% carbamide peroxide (CP), 6 h/day]. After each bleaching session the specimens were stored in human saliva. Knoop microhardness and surface roughness were measured: before bleaching, after 2-week and after 8-week bleaching. After 2-week treatment, surface roughness was significantly increased in all experimental groups (p < 0.05), while among them no significant difference was found (p > 0.05). The roughness changes exerted after 8-week bleaching were not significantly higher than the ones after 2 weeks (p > 0.05). After 8-week treatment, the increase in roughness caused by 16% CP was significantly higher (p < 0.05) than the one caused by 40% H2O2. Microhardness increased in all groups including control; however, only 40% H2O2 increased the microhardness significantly (p < 0.05). The effect of bleaching on enamel was not shown to be dependent on the method or the H2O2 concentration. Bleaching with CP 16% resulted in higher roughness than bleaching with H2O2, while 40% H2O2 caused the higher microhardness increase. The present study showed that in-office bleaching with 40% H2O2 seems to be at least as safe as home bleaching as far as their effects on human enamel are concerned.

Fluoride/vitamin D tablet supplementation in infants-effects on dental health after 10 years.

OBJECTIVE: We examined whether fluoride/vitamin D supplementation in the first year of life is associated with caries or molar incisor hypomineralization (MIH) at 10 years of age. METHODS: The study population consisted of 406 children for whom information on fluoride/vitamin D supplementation during the first year of life was available. Dental examination at the age of 10 included caries and MIH registration. The results of logistic regression models were adjusted for gender, age, BMI, parental education, and equivalent income. RESULTS: Children receiving supplementation during the entire first year of life had a significantly lower probability of having caries-related restorations in primary teeth in comparison to those who received supplementation for less than 6 months (fluoride supplementation: odds ratio (OR) for d3-4mfs 2.47 (1.32-4.63), for fs 2.70 (1.43-5.10); vitamin D supplementation: OR for d3-4mfs 2.08 (1.00-4.32), fs 2.50 (1.19-5.25)). The majority of logistic regression analyses indicated no association between supplementation and MIH. CONCLUSIONS: It was found a consistent significant caries-preventive effect in the primary dentition of children who received fluoride (256/372)/vitamin D supplementation (274/376) in all 12 months over the first year of life; no effects were observed for permanent dentition. The high parental interest in supplementation is linked to an imbalance of the study groups. Furthermore, tooth brushing frequency, use of fluoride toothpastes and/or other oral hygiene products were not recorded during the observation period which may also confound the results. CLINICAL RELEVANCE: Fluoride/vitamin D supplementation can be used in children for preventing caries in the primary dentition.

Evaluation of Surface Roughness of Ceramic and Resin Composite Material Used for Conservative Indirect Restorations, after Repolishing by Intraoral Means.

PURPOSE: To evaluate and compare the mean surface roughness (Ra) of one ceramic and one resin composite material used for indirect restorations, after grinding and repolishing by intraoral means. MATERIALS AND METHODS: The materials used were the lithium disilicate glass ceramic IPS e.max Press (EMP) and the indirect resin composite restoration system Gradia (GR). Twelve specimen disks were prepared from each material according to the manufacturer of each material. Five initial measurements of the Ra (Ra1 ) were made on each specimen as a referral basis, and the specimens were ground with a fine (red) diamond bur. The specimens were repolished using (a) Komet Dialite Polishing Kit for EMP and (b) Enhance Finishing and Polishing System and Prisma Gloss Polishing Paste for GR. Five final Ra (Ra2 ) measurements were performed on each specimen. All measurements were made using a laser profilometer. Scanning electron microscopy (SEM) was also used to visualize the initial surface morphology and the morphological changes on the specimens' surface after repolishing. RESULTS: A highly significant difference was found between Ra1EMP and Ra2EMP (p < 0.001), between Ra1GR and Ra2GR (p < 0.001), as well as between Ra2EMP and Ra2GR (p < 0.001), when compared in pairs. A highly significant difference (p < 0.001) was also found between ΔRaEMP and ΔRaGR , with ΔRaGR being higher than ΔRaEMP . The RaGR values were higher than the RaEMP values at all times. SEM revealed that both EMP and GR repolished surfaces presented with irregularities; however, in GR specimens major voids and craters were present. CONCLUSIONS: EMP was found to perform better when polished by intraoral means compared with GR. Both materials exhibited Ra2 above the critical threshold for increased plaque accumulation and periodontal inflammation. If enamel-to-enamel roughness found in occlusal contact areas is considered as baseline, both materials were clinically acceptable after repolishing.