Treatment Durations and Whitening Outcomes of Different Tooth Whitening Systems.

Background and Objectives: Tooth whitening is a relatively conservative and effective option to treat discolored teeth. However, questions remain whether in-office or at-home tooth whitening products with short treatment durations are as effective and stable as products with longer treatment durations. Materials and Methods: Forty human third molars with intact enamel surfaces were divided into four groups of ten each, subjected to discoloration challenges with coffee for 60 h, and they were treated with four professional tooth whitening systems: two for take-home use-6% hydrogen peroxide for 30 min/d for a total of 7 h in 14 days (HP6), 10% carbamide peroxide for 10 h/d for 140 h in 14 days (CP10), as well as two for in-office use-35% HP for 10 min × 3 (HP35) for a total of 30 min and 40% HP for 20 min × 3 (HP40) for a total of 60 min. Teeth colors were assessed in the CIE L*a*b* color space with a spectrophotometer immediately and six months after whitening treatments. Surface roughness (Sa) for the treated and untreated enamel surfaces of the teeth in all groups were evaluated with a three-dimensional laser scanning microscope after six months. Results: No significant differences were found between HP6 and CP10 groups immediately after whitening (∆E 10.6 ± 1.6 vs. 11.4 ± 1.7, p > 0.05) and at six months after treatments (∆E 9.0 ± 1.9 vs. 9.2 ± 2.5, p > 0.05), or between HP35 and HP40 groups immediately after whitening (∆E 5.9 ± 1.2 vs. 5.3 ± 1.7, p > 0.05) and at six months after treatments (∆E 7.2 ± 1.6 vs. 7.7 ± 1.3, p > 0.05). The two at-home whitening systems achieved significantly better whitening outcomes than the two in-office products immediately after whitening (p < 0.05). However, at six months after treatments, the differences between at-home and in-office treatments had narrowed significantly (p > 0.05). There were no statistically significant differences with respect to the Sa values between the treated and untreated surfaces (p > 0.05). Conclusions: Tooth whitening products in the same product category have similar whitening efficacies, despite significant differences in treatment durations (7 vs. 140 h, and 30 min vs. 60 min, respectively). Take-home products achieved better whitening outcomes than in-office products, but they needed 14 to 280 times longer treatment durations.

Clinical characteristics and risk factors of major oral ulcers in the mandibular retromolar region in children.

OBJECTIVES: To describe the characteristics of major aphthous ulcers (MjOU) in children and analyze its potential risk factors. MATERIALS AND METHODS: Data were collected from the National Clinical Research Center for Oral Diseases of China between 2012 and 2017. Children younger than 15 years old, who had a giant mucosa ulcer (≥ 1 cm in diameter) and met the diagnostic criteria for MjOU were included in this study. Differences were compared between two subgroups of patients based on the location of the ulcerous lesions. A measurement of ratio (TBR) between the length of the mandibular second molar tooth germ and the height of the mandible was performed in children with MjOU lesions located in the mandibular retromolar pad region (MjOU-P) and their age- and sex-matched controls. RESULTS: A total of 1067 children were diagnosed with oral ulcers during the study period, of which 125 (11.7%, 95% CI: 9.8%-13.7%) met the diagnostic criteria for MjOU. More than half (n = 64, 51.2%) of the MjOU cases were MjOU-P, which had a male predilection (n = 52, 81.3%) with a significant majority at 7 to 9 years of age (n = 43, 67.2%). In comparison to the MjOU located in other regions, MjOU-P lasted longer in duration and had more comorbidities. Logistic regression analysis showed that MjOU-P was statistically significantly associated with TBR controlling age and gender. CONCLUSIONS: MjOU-P is a predominant form of MjOU in children and is a distinct subgroup of major ulcers that is likely associated with the development of the mandibular second molars. CLINICAL RELEVANCE: This study is the first to describe the demographic and clinical features of MjOU in children, which may facilitate the identification and treatment of these patients.

Effects of whitening toothpaste and bleaching treatment on resin composite discoloration caused by cigarette smoke and electronic vapor aerosol.

PURPOSE: To compare the effects of whitening toothpaste and bleaching with 6% hydrogen peroxide (H2O2) on discoloration of dental resin composite caused by cigarette smoke (CS) and electronic vapor product (EVP) aerosol. METHODS: 40 resin composite discs were divided into three groups: 15 each for CS and EVP aerosol exposure and 10 for air exposure (control). Exposures were performed for 15 days, with daily brushing with regular toothpaste. Two whitening sessions, including 21 days of brushing with whitening toothpaste and 3 days of treatments with take-home bleaching (6% H2O2), were performed after the exposure. Color and gloss were assessed before exposure, at every 5 days of exposure, and after each whitening session. RESULTS: After 15 days of exposure, marked discoloration of resin composite was observed in the CS group (ΔE = 23.66 ± 2.31), minimal color change in the EVP group ((ΔE = 2.77 ± 0.75), and no color change in the control group. Resin composites exposed to CS did not recover their original color after treatment with whitening toothpaste ((ΔE = 20.17 ± 2.68) or take-home bleaching ((ΔE = 19.32 ± 2.53), but those exposed to EVP aerosol reverted to baseline after treatment with whitening toothpaste ((ΔE = 0.98 ± 0.37), and no further change in color was observed following take-home bleaching. The gloss of resin composites exposed to CS, EVP aerosol, and air decreased equally with exposure time. Brushing with whitening toothpaste recovered the gloss similarly in all groups, but no further change was observed following take-home bleaching. CLINICAL SIGNIFICANCE: Aerosol from electronic vapor products induced minimal discoloration of resin composites that can be completely reverted by brushing with whitening toothpaste alone. Bleaching with 6% H2O2 did not revert discoloration caused by cigarette smoke. Whitening toothpaste could help revert the decreased gloss of resin composites.

Effects of desensitizing dentifrices on dentin tubule occlusion and resistance to erosive challenges.

BACKGROUND: Many studies have demonstrated efficacy of casein phosphopeptide (CPP) containing products for dentin tubule occlusion for treatment of dentin sensitivity, but their effectiveness under dynamic erosive challenges remains to be elucidated. The purpose of the present study was to investigate the effectiveness of a desensitizing dentifrice containing CPP in occluding dentin tubules and resisting erosive challenges in comparison to that containing polyvinyl methyl ether/maleic acid (PVM/MA) copolymers. METHODS: A total of 33 dentin discs were prepared from coronal sections of human third molars and divided into 3 groups: a toothpaste containing CPP; a toothpaste containing PVM/MA and submicron silica; and a regular toothpaste (Controls). A soft-bristle toothbrush was used to brush the dentin discs with the dentifrices for 45 strokes in 30 s at a force of approximately 200 g. The brushing cycle was repeated after immersion of the dentin discs in artificial saliva overnight. The dentin discs were then challenged in orange juice for 10 min in an incubator rocking at 120 rpm. Three fields were randomly selected on each dentin disk surface to assess dentin tubule occlusions after each brushing cycle and after orange juice challenge with a 3D laser scanning microscope. Specimen cross sections were examined with a scanning electron microscope equipped with energy dispersive spectroscopy (SEM/EDS). RESULTS: After the first and second cycles of brushing, dentin tubules were occluded on average by 56.3% and 85.7% in CPP group, 66.2% and 88.1% in PVM/MA group, and 0.0 and 13.0% in the controls, respectively. There were no statistically significant differences in dentin tubule occlusions between the CPP and PVM/MA groups after two cycles of brushing (p>0.05). After dynamic erosive challenges with orange juice, 20.3% of the dentin tubules in the CPP group, 79.1% in the PVM/MA group and none in the control remained occluded (P<0.05). SEM/EDS imaging showed that dentin tubules were blocked with plugs containing dentifrice substances in CPP and PVM/MA groups after treatments, but none in the controls. CONCLUSIONS: Desensitizing dentifrices containing CPP or PVM/MA could effectively occlude dentin tubules after two cycles of brushing. PVM/MA in combination with submicron silicon dioxide exhibited stronger resistance to dynamic erosive challenges by acidic beverages. Inorganic fillers that can enter dentin tubules and resist erosive challenges may be key for desensitizing dentifrices.

Pathogenesis, diagnosis and management of dentin hypersensitivity: an evidence-based overview for dental practitioners.

Though dentin hypersensitivity (DHS) is one of the most common complaints from patients in dental clinics, there are no universally accepted guidelines for differential diagnosis as well as selection of reliable treatment modalities for this condition. The neurosensory mechanisms underlying DHS remain unclear, but fluid movements within exposed dentinal tubules, i.e., the hydrodynamic theory, has been a widely accepted explanation for DHS pain. As several dental conditions have symptoms that mimic DHS at different stages of their progression, diagnosis and treatment of DHS are often confusing, especially for inexperienced dental practitioners. In this paper we provide an up-to-date review on risk factors that play a role in the development and chronicity of DHS and summarize the current principles and strategies for differential diagnosis and management of DHS in dental practices. We will outline the etiology, predisposing factors and the underlying putative mechanisms of DHS, and provide principles and indications for its diagnosis and management. Though desensitization remains to be the first choice for DHS for many dental practitioners and most of desensitizing agents reduce the symptoms of DHS by occluding patent dentinal tubules, the long-term outcome of such treatment is uncertain. With improved understanding of the underlying nociceptive mechanisms of DHS, it is expected that promising novel therapies will emerge and provide more effective relief for patients with DHS.

Phytotoxicity Assessment of Copper Oxide Nanoparticles on the Germination, Early Seedling Growth, and Physiological Responses in Oryza sativa L.

The increasing utilization of copper oxide nanoparticles (CuO NPs) and their release into the environment has made it imperative to elucidate their impact on the ecological system including plants. However, their potential toxic impact and mechanisms on plant growth are still unclear. The aim of this study was to investigate the effects of CuO NPs and released Cu ions on seed germination and early seedling growth, as well as physiological and biochemical parameters of Oryza sativa. The results showed that CuO NPs at high concentration significantly inhibited seed germination and early seedling growth. The toxicity of CuO NPs originated from the particulate NPs rather than the released Cu2+. The phytotoxicity of CuO NPs to rice seed germination and seedling growth probably induced by high Cu accumulation along with the lignification and oxidative damage. The work presented here will increase our knowledge of phytotoxicity of CuO NPs.

Prenatal Oral Health Care and Early Childhood Caries Prevention: A Systematic Review and Meta-Analysis.

Despite the advancement of early childhood caries (ECC) prediction and treatment, ECC remains a significant public health burden in need of more effective preventive strategies. Pregnancy is an ideal period to promote ECC prevention given the profound influence of maternal oral health and behaviors on children's oral health. However, studies have shown debatable results with respect to the effectiveness of ECC prevention by means of prenatal intervention. Therefore, this study systematically reviewed the scientific evidence relating to the association between prenatal oral health care, ECC incidence, and Streptococcus mutans carriage in children. Five studies (3 randomized control trials, 1 prospective cohort study, and 1 nested case-control study) were included for qualitative assessment. Tested prenatal oral health care included providing fluoride supplements, oral examinations/cleanings, oral health education, dental treatment referrals, and xylitol gum chewing. Four studies that assessed ECC incidence reduction were included in meta-analysis using an unconditional generalized linear mixed effects model with random study effects and age as a covariate. The estimated odds ratio and 95% confidence intervals suggested a protective effect of prenatal oral health care against ECC onset before 4 years of age: 0.12 (0.02, 0.77) at 1 year of age, 0.18 (0.05, 0.63) at 2 years of age, 0.25 (0.09, 0.64) at 3 years of age, and 0.35 (0.12, 1.00) at 4 years of age. Children's S. mutans carriage was also significantly reduced in the intervention group. Future studies should consider testing strategies that restore an expectant mother's oral health to a disease-free state during pregnancy.

Effectiveness of resin-based materials against erosive and abrasive enamel wear.

OBJECTIVE: The objective of this study was to test the effectiveness of resin-based materials against erosive enamel wear under erosive and abrasive challenges by orange juice and tooth brushing. METHODS: Fifty enamel specimens from third molars were assigned to five groups: ICON resin infiltration with no etching (ICON-NE), ICON resin infiltration with 15 % HCl etching (ICON-AE), Seal & Protect sealant (S&P), Tetric EvoFlow (TEF), and control. Erosive lesions were first created on enamel, then treated with resin-based materials. Erosive and abrasive challenges by orange juice and tooth brushing were repeated after treatments. Erosive wear of the treated areas was measured with 3D scanning microscopy, and data were analyzed using ANOVA and paired t tests. RESULTS: Treatments with ICON, S&P, and TEF created a protective material coating of 4.5 ± 1.9 µm, 44.3 ± 8.1 µm, and 84.6 ± 15.7 µm in thickness on the lesion surfaces, respectively. After 15 cycles of erosive and abrasive challenges, enamel or material losses were 21.9 ± 2.3 µm for control, 24.5 ± 4.0 µm for ICON-NE, 24.6 ± 7.4 µm for ICON-AE, 11.2 ± 4.1 µm for S&P, and 3.9 ± 1.9 µm for TEF, respectively. The protective coatings were completely lost in the ICON infiltration groups but remained intact in both the S&P and TEF groups after erosive and abrasive challenges. CONCLUSION: In contrast to a resin sealant and a flowable composite, ICON infiltration resin was not effective in protecting enamel surfaces from erosive and abrasive wear. CLINICAL RELEVANCE: Sealant and flowable composite resin may create protective coatings on eroded enamel surfaces and prevent further tissue loss.

Effects of cigarette smoking on color stability of dental resin composites.

PURPOSE: To study the effects of cigarette smoke (CS) on the discoloration of dental resin composite compared with the aerosol from a heat-not-burn tobacco product, the Tobacco Heating System 2.2 (THS2.2). METHODS: A total of 60 discs were prepared from three commercial resin composites: Durafill VS (DVS), Filtek Supreme Ultra (FSU) and Tetric EvoCeram BulkFill (TEC). Twenty discs of each composite were divided into two groups and exposed to CS from 20 reference cigarettes (3R4F) or aerosol from 20 THS2.2 tobacco sticks per day for 3 weeks. Color, gloss and surface roughness of the composite discs were measured at baseline and after exposure and brushing with toothpaste at 1, 2 and 3 weeks. RESULTS: Color differences from the baseline (ΔE) were on average 27.1 (±3.6) in 3R4F and 3.9 (±1.5) in the THS2.2 group after 3 weeks of exposure (P< 0.0001). TEC (30.4±1.4 and FSU (28.0 ±2.5) exhibited more discoloration than DVS (23.0±1.2) in the 3R4F group (P< 0.0001). FSU (2.6 ±0.5) showed significantly less discoloration than TEC (5.3±1.5) in the THS2.2 group (P< 0.0001). Surface roughness of resin composites was not affected by either CS or THS2.2 aerosol, while surface gloss increased in the composite discs with more severe discoloration. CLINICAL SIGNIFICANCE: Cigarette smoke caused significant discoloration of dental composite resins. Reducing or eliminating the deposits derived from combustion of tobacco has the potential to minimize the impact of smoking on the color of composite resin restorations.

Success rate of short dental implants supporting single crowns and fixed bridges.

OBJECTIVE: Bone grafts (sinus lift and/or ridge augmentation) may become an obstacle for some patients who desire implant treatment. The objective of this study was to evaluate the success of six- and eight-millimeters rough surface design short dental implants, for up to 2 years in function, when compared to conventional length (11 mm) implants. MATERIALS AND METHODS: A total of 25.6-, 20.8- and 35.11-mm length implants were placed and restored in 30 subjects (11 males, 19 females) between the age of 22 and 80, following a standard protocol. Implant mobility, crestal bone loss as well as periodontal parameters were evaluated immediately after restoration placement, at 6, 12 and 24 months. RESULTS: There was one failure of one 6-mm implant during the healing phase and one restorative failure. The median crestal bone loss at 24 months was 0.45 mm for the 6-mm implants, 0.55 mm for the 8 mm implants and 0.65 mm for the 11-mm implants. The success rate for 6-mm implants was 97% and for 8-mm and 11-mm implants 100%. CONCLUSIONS: Based on this preliminary data, we conclude that rough surface design short dental implants (6 and 8 mm in length) have similar success rate when compared to 11-mm implants. Long-term data with larger number of implants and subjects are needed to confirm these results.

Reciprocal interaction between dental alloy biocorrosion and Streptococcus mutans virulent gene expression.

Corrosion of dental alloys is a major concern in dental restorations. Streptococcus mutans reduces the pH in oral cavity and induces demineralization of the enamel as well as corrosion of restorative dental materials. The rough surfaces of dental alloys induced by corrosion enhance the subsequent accumulation of plaque. In this study, the corrosion process of nickel-chromium (Ni-Cr) and cobalt-chromium (Co-Cr) alloys in a nutrient-rich medium containing S. mutans was studied using inductively coupled plasma atomic emission spectrometry (ICP-AES), X-ray photoelectron spectroscopy (XPS) and electrochemical corrosion test. Our results showed that the release of Ni and Co ions increased, particularly after incubation for 3 days. The electrochemical corrosion results showed a significant decrease in the corrosion resistance (Rp) value after the alloys were immersed in the media containing S. mutans for 3 days. Correspondingly, XPS revealed a reduction in the relative dominance of Ni, Co, and Cr in the surface oxides after the alloys were immersed in the S. mutans culture. After removal of the biofilm, the pre-corroded alloys were re-incubated in S. mutans medium, and the expressions of genes associated with the adhesion and acidogenesis of S. mutans, including gtfBCD, gbpB, fif and ldh, were evaluated by detecting the mRNA levels using real-time reverse transcription polymerase chain reaction (RT-PCR). We found that the gtfBCD, gbpB, ftf and Idh expression of S. mutans were noticeably increased after incubation with pre-corroded alloys for 24 h. This study demonstrated that S. mutans enhanced the corrosion behavior of the dental alloys, on the other hand, the presence of corroded alloy surfaces up-regulated the virulent gene expression in S. mutans. Compared with smooth surfaces, the rough corroded surfaces of dental alloys accelerated the bacteria-adhesion and corrosion process by changing the virulence gene expression of S. mutans.

Healing outcomes of open versus closed flap procedures for collagen membrane coverage following immediate dental implant placements with simultaneous guided tissue regeneration.

OBJECTIVE: To compare the outcomes of open healing to complete closure for collagen membrane coverage for immediate implant placements with simultaneous guided bone regeneration (GBR) in two retrospective cohorts. METHODS: The subjects included 118 patients who received Bio-Gide® collagen membrane coverage for immediate implant placements and GBR in 20 anterior and 98 posterior teeth. For 58 patients, gingival flaps were released to achieve full coverage of collagen membrane (CC group). For 60 patients, no efforts were made to release the gingival flaps and collagen membrane was left exposed for open healing (OH group). Antibiotics and analgesics were prescribed for 7 days after surgery. The width of crestal open wounds were measured after surgery (W0), and at 1, 2 and 16 weeks (W16). Changes in bone mass were assessed by cone-beam computed tomography after implant placement and again at W16. Gingival and bone tissues over the implant cover screws were harvested and assessed for 16 patients in the OH group at W16. RESULTS: No wound dehiscence occurred in the CC group from W0 to W16. Both the vertical and horizontal bone dimension changes were not significantly different between the OH and CC group. For the OH group, soft tissue was completely healed at W16 when the initial wound widths were ≤6 mm. For those with initial wound widths ≥ 7 mm, the cover screws were exposed in 5/16 patients at W16 but did not affect the final restorations. Tissue staining showed keratinized mucosa and new bone formation above the dental implant in the OH group. CONCLUSION: Open healing achieved healing outcomes similar to those of complete closure for collagen membrane coverage following immediate implant placements. CLINICAL SIGNIFICANCE: For immediate implant placement requiring bone grafting and collagen membrane coverage, it is unnecessary to release the gingival flaps or use tissue grafts to achieve full coverage of the crestal wounds. Open healing with exposed membrane could achieve similar outcomes with less pain and swelling.

Expert consensus on endodontic therapy for patients with systemic conditions.

The overall health condition of patients significantly affects the diagnosis, treatment, and prognosis of endodontic diseases. A systemic consideration of the patient's overall health along with oral conditions holds the utmost importance in determining the necessity and feasibility of endodontic therapy, as well as selecting appropriate therapeutic approaches. This expert consensus is a collaborative effort by specialists from endodontics and clinical physicians across the nation based on the current clinical evidence, aiming to provide general guidance on clinical procedures, improve patient safety and enhance clinical outcomes of endodontic therapy in patients with compromised overall health.

Dentin tubule occlusion and erosion protection effects of dentifrice containing bioadhesive PVM/MA copolymers.

OBJECTIVES: To study the effectiveness of a dentifrice containing polyvinylmethyl ether-maleic acid (PVM/MA) copolymer in occluding dentin tubules and investigate the interaction between PVM/MA and type I collagen using surface plasmon resonance (SPR). MATERIALS AND METHODS: Fifteen volunteers brushed dentin discs in situ using dentifrices with and without PVM/MA copolymer in a cross-over design. Dentin tubule occlusion was evaluated after brushing, after overnight saliva challenge in vivo for 12 h and after drinking 250 ml of orange juice. Dentin tubule occlusion and tubule size were compared between the two groups using repeated ANOVA and before and after erosive challenges using paired t tests. SPR using type I collagen as ligand and PVM/MA as analyte was performed to evaluate the binding of the two macromolecules. RESULTS: A median of 91% of dentin tubules were occluded after a single brushing in the PVM/MA group, as compared to 9% in the controls. After overnight saliva challenge and 10 min of erosion by orange juice, a median of 73% of the dentin tubules remained fully occluded in the PVM/MA group as compared to zero in the controls. Dentin tubule size increased after orange juice erosion in the controls but not in the PVM/MA group. SPR study showed that PVM/MA bound readily to collagen molecules in a 4 to 1 ratio. CONCLUSIONS: Dentifrice containing PVM/MA could effectively occlude dentin tubules and prevent dentin erosion. PVM/MA may improve adhesive retention of intra-tubular dentifrice plugs through binding to dentin surface collagen. CLINICAL RELEVANCE: Brushing with dentifrice containing adhesive polymers has preventive effect against dentin erosion and dentin sensitivity.

Anti-cariogenic Properties of Lactobacillus plantarum in the Utilization of Galacto-Oligosaccharide.

Ecological approaches can help to correct oral microbial dysbiosis and drive the advent and persistence of a symbiotic oral microbiome, which benefits long-term dental caries control. The aim of this study was to investigate the impact of the prebiotic Galacto-oligosaccharide (GOS) on the growth of probiotics L. plantarum 14,917 and its effect on the inhibitory ability of L. plantarum 14,917 against the growth of Streptococcus mutans and Candida albicans in an in vitro model. Single-species growth screenings were conducted in TSBYE broth with 1% glucose and 1-5% GOS. Interaction experiments were performed using duo- and multi-species models with inoculation of 105 CFU/mL S. mutans, 103 CFU/mL C. albicans, and 108 CFU/mL L. plantarum 14,917 under 1%, 5% GOS or 1% glucose. Viable cells and pH changes were measured. Real-time PCR was utilized to assess expression of C. albicans and S. mutans virulence genes. Six replicates were used for each group. Student's t-test, one-way ANOVA, and Kruskal-Wallis were employed to compare the outcomes of different groups. GOS significantly inhibited the growth of C. albicans and S. mutans in terms of growth quantity and speed when the two strains were grown individually. However, GOS did not affect the growth of L. plantarum 14,917. Moreover, 1% and 5% GOS enhanced the anti-fungal performance of L. plantarum 14,917 in comparison to 1% glucose. GOS as the carbon source resulted in a less acidic environment in the C. albicans and S. mutans duo-species model and multispecies model where L. plantarum 14,917 was added. When GOS was utilized as the carbohydrate substrate, S. mutans and C. albicans had a significant reduction in the expression of the HWP1, ECE1, atpD, and eno genes (p < 0.05). To our knowledge, this is the first study that reported the ability of GOS to neutralize S. mutans-C. albicans high caries of medium pH and to disrupt virulence gene expression. Moreover, as a prebiotic, GOS augmented the inhibitory ability of L. plantarum against C. albicans in vitro. The current study revealed the anti-caries potential of prebiotics GOS and shed light on novel caries prevention strategies from the perspective of prebiotics and probiotics. These findings provide a rationale for future biofilm or clinical studies to elucidate the effect of GOS on modulating oral microbiota and caries control.

Dose-Dependent Inhibitory Effect of Probiotic Lactobacillus plantarum on Streptococcus mutans-Candida albicans Cross-Kingdom Microorganisms.

Dental caries is one of the most common chronic diseases worldwide. Streptococcus mutans and Candida albicans are two major pathogens associated with dental caries. Several recent studies revealed that Lactobacillus plantarum inhibits S. mutans and C. albicans in biofilms and in a rodent model of dental caries. The aim of this study was to investigate the dose-dependent effect of L. plantarum against S. mutans and C. albicans in a planktonic model that simulated a high-caries-risk clinical condition. Mono-, dual-, and multi-species models were utilized, with five doses of L. plantarum (ranging from 1.0 × 104 to 1.0 × 108 CFU/mL). Real-time PCR was used to assess the expression of the virulence genes of C. albicans and S. mutans and the genes of L. plantarum. Student's t-tests and one-way ANOVA, followed by post hoc tests, were employed to compare the cell viability and gene expression among groups. A dose-dependent inhibition on C. albicans and S. mutans was observed with increased dosages of L. plantarum. L. plantarum at 108 CFU/mL demonstrated the highest antibacterial and antifungal inhibitory effect in the dual- and multi-species models. Specifically, at 20 h, the growth of C. albicans and S. mutans was suppressed by 1.5 and 5 logs, respectively (p < 0.05). The antifungal and antibacterial effects were attenuated in lower doses of L. plantarum (104-107 CFU/mL). The expression of C. albicans HWP1 and ECE 1 genes and S. mutans lacC and lacG genes were significantly downregulated with an added 108 CFU/mL of L. plantarum (p < 0.05). The addition of 108 CFU/mL L. plantarum further inhibited the hyphae or pseudohyphae formation of C. albicans. In summary, L. plantarum demonstrated dose-dependent antifungal and antibacterial effects against C. albicans and S. mutans. L. plantarum emerged as a promising candidate for the creation of novel antimicrobial probiotic products targeting dental caries prevention. Further research is warranted to identify the functional metabolites produced by L. plantarum at different dosages when interacting with C. albicans and S. mutans.

Clinical practice guidelines for oral health care during pregnancy: a systematic evaluation and summary recommendations for general dental practitioners.

OBJECTIVE: To evaluate and summarize clinical practice guidelines on the prevention, diagnosis, and treatment of dental diseases during pregnancy, and to provide summary recommendations for general dental practitioners involved in the dental care of pregnant women. METHOD AND MATERIALS: Using keywords related to prenatal dental care in combination with guidelines or consensus statements, online databases, websites of professional organizations, and evidence-based practice platforms were searched. Published guidelines or consensus statements that met the inclusion criteria were selected and evaluated with the Appraisal of Guidelines for Research & Evaluation Instrument II (AGREE-II) tool. Key recommendations were summarized and assessed for consistency across the guidelines. RESULTS: A total of 15 guidelines or consensus statement documents for oral health care during pregnancy were found after the initial search, of which 7 documents met the inclusion criteria; these were analyzed with AGREE-II. These guidelines were developed by expert panels and consensus meetings after comprehensive review of the best available evidence, and consistently deliver clear messages that preventive, diagnostic, restorative, and periodontal procedures and tooth extractions are safe throughout pregnancy and effective in improving and maintaining the oral health of mothers and their children. Dental diseases should be treated in a timely manner and dental emergency treatments can be provided at any time during pregnancy. Dental examination and prophylaxis should be conducted every 6 months to maintain the oral health of pregnant women. CONCLUSION: Published clinical guidelines are consistent in delivering clear messages and providing guidance to dental practitioners for timely and effective dental care during pregnancy. Prevention, diagnosis, and treatment of oral diseases are safe throughout the pregnancy.

Effects of mechanical ventilation and portable air cleaner on aerosol removal from dental treatment rooms.

OBJECTIVES: To evaluate the mechanical ventilation rates of dental treatment rooms and assess the effectiveness of aerosol removal by mechanical ventilation and a portable air cleaner (PAC) with a high-efficiency particulate air (HEPA) filter. METHODS: Volumetric airflow were measured to assess air change rate per hour by ventilation (ACHvent). Equivalent ventilation provided by the PAC (ACHpac) was calculated based on its clean air delivery rate. Concentrations of 0.3, 0.5 and 1.0 µm aerosol particles were measured in 10 dental treatment rooms with various ventilation rates at baseline, after 5-min of incense burn, and after 30-min of observation with and without the PAC or ventilation system in operation. Velocities of aerosol removal were assessed by concentration decay constants for the 0.3 µm particles with ventilation alone (Kn) and with ventilation and PAC (Kn+pac), and by times needed to reach 95 % and 100 % removal of accumulated aerosol particles. RESULTS: ACHvent varied from 3 to 45. Kn and Kn+pac were correlated with ACHvent (r = 0.90) and combined ACHtotal (r = 0.81), respectively. Accumulated aerosol particles could not be removed by ventilation alone within 30-min in rooms with ACHvent<15. PAC reduced aerosol accumulation and accelerated aerosol removal, and accumulated aerosols could be completely removed in 4 to 12-min by ventilation combined with PAC. Effectiveness of the PAC was especially prominent in rooms with poor ventilation. Added benefit of PAC in aerosol removal was inversely correlated with ACHvent. CONCLUSIONS: Aerosol accumulation may occur in dental treatment rooms with poor ventilation. Addition of PAC with a HEPA filter significantly reduced aerosol accumulation and accelerated aerosol removal. CLINICAL SIGNIFICANCE: Addition of PAC with a HEPA filter improves aerosol removal in rooms with low ventilation rates.

Evaluation of packable and conventional hybrid resin composites in Class I restorations: three-year results of a randomized, double-blind and controlled clinical trial.

The clinical performance of packable and conventional hybrid resin composites in Class I restorations for a period of three years was compared using a randomized controlled double-blind clinical trial with self-matching design. A total of 50 pairs of Class I restorations were placed in 32 adult patients by one dentist in a self-matching prospective clinical trial. The paired teeth were divided into the TPH Spectrum/XenoIII (TS) restoration group and the Synergy Compact/One Coat (SC) restoration group according to a random number table. Application of the materials followed the manufacturer's instructions. The restorations were evaluated by two independent evaluators using US Public Health Service (USPHS)-Ryge modified criteria. Statistical analysis was performed using the McNemar's test with Yates' continuity correction. After three years, 40 pairs of restorations were available for evaluation. Four TS and two SC restorations failed due to fracture. Only one TS-restored tooth showed postoperative sensitivity at baseline and the symptom disappeared one week later. Alpha ratings of TS vs SC restorations were as follows: 95% vs 98% for color match, 85% vs 88% for marginal integrity, 88% vs 90% for anatomical form, 85% vs 83% for marginal discoloration, 88% vs 93% for occlusal contact. For both materials, Alpha ratings were 88% for surface texture. The three-year clinical performances of the two restorative materials were satisfactory and not significantly different for each of the parameters evaluated.

Platelet-rich plasma in sinus augmentation procedures: a systematic literature review: Part II.

BACKGROUND: Although platelet-rich plasma (PRP) has been extensively studied for over a decade, there are no definitive reports, which prove the benefit of using PRP in sinus augmentation procedures. In addition, no systematic literature review has been done to report the benefit of treatment outcome in patients who received PRP in conjunction with bone/bone substitutes in maxillary sinus augmentation procedures. Therefore, it can be rightly stated that evidence for an adjunctive benefit of using PRP with bone grafts in sinus augmentation procedures is equivocal and inconclusive. AIM: : The objective of this systematic literature review was to examine this literature in determining whether PRP with bone and bone substitutes leads to more rapid and effective bone regeneration clinically, radiographically, and histologically with sinus augmentation procedures and was there any clinical data parallel to animal experiments providing clinical evidence in sinus augmentation procedures? METHODS: A systematic review of randomized clinical trials of at least 6 months duration was conducted comparing PRP and bone/bone substitutes (test group) to bone/bone substitutes (control group) alone. Electronic databases such as MEDLINE and CENTRAL (Cochrane central register of controlled clinical trials) were searched for relevant articles. The reference list of all included articles was searched along with unpublished clinical trials whose abstracts were available. RESULTS: Although, there is a lack of human studies, which show benefit of using PRP in conjunction with bone grafting materials, it can be stated that use of PRP does lead to early regeneration and reduction in healing time of soft and hard tissues. However, no significant statistical or clinical benefit was reported from studies that would satisfy the inclusion criteria. This study answers the question very clearly that at this point of time, there is no human study that strongly supports the benefit of using PRP in sinus augmentation procedures. CONCLUSION: There is a paucity of clinically controlled trials regarding benefits of PRP in sinus augmentation procedures. Theoretically, it seems to have significant beneficial effects on the soft and hard tissue healing; however, the disparity in study design, surgical techniques, and different outcome assessment variables used, makes it difficult to assess the practical benefit of its clinical use. Although no obvious positive effects of PRP on healing of bone graft material in maxillary sinus augmentation procedures were noted, the handling of the particulate bone grafts was improved.