PURPOSE:To investigate the clinical effectiveness of perioperative nursing interventions based on the Knowledge-Attitude-Practice (KAP) theory in patients undergoing robot-assisted dental implant surgery. METHODS:A total of 54 patients who underwent robot-assisted dental implant surgery were allocated to either a conventional perioperative care group (control group) or a KAP intervention group. The control group received routine perioperative care according to the hospital's standard protocols, whereas the intervention group received perioperative care based on the KAP theory in addition to the standard care. The KAP-based care followed a progressive pathway characterized by knowledge dissemination, attitude cultivation, and behavioral guidance. The intervention period lasted for 8 weeks. Primary outcome measures included self-care ability, negative emotions, postoperative swelling and pain, follow-up compliance, and patient satisfaction. RESULTS:After 8 weeks, the intervention group exhibited significantly greater improvements in all domains of self-care behavior (regular follow-up, correct toothbrushing, and balanced diet) as well as in total self-efficacy scores compared with the control group. Dental anxiety and dental fear scores decreased significantly in both groups, with greater reductions in the intervention group. Postoperative pain scores were significantly lower and satisfaction scores significantly higher in the intervention group. At 3 and 6 months, compliance rates in the intervention group were significantly higher than those in control group. CLINICAL SIGNIFICANCE:Perioperative nursing based on the Knowledge-Attitude-Practice (KAP) theory enhanced self-care ability, alleviated negative emotions, increased long-term follow-up compliance, and improved patient satisfaction in individuals undergoing robot-assisted dental implant surgery. This model effectively standardizes patient care behaviors and optimizes postoperative recovery.
PURPOSE:This study evaluated the cross-sectional Knoop microhardness (KHN) of enamel and dentin adjacent to restorations made with bioactive materials, and their surface degradation after pH cycling. METHODS:Molar blocks (n=10) were restored with conventional resin composite (RC; Z350XT), resin-modified glass-ionomer cement (R-GIC; Vitremer), flowable compomer (FC; Twinky), resin composite with S-PRG filler (RC-S-PRG; Beautifil II), or self-curing bioactive composite (RC-SP; Cention N). After pH cycling, KHN was measured at 100, 200, and 300 µm from the restoration margins and at depths of 20, 40, and 60 µm from the surface. Surfaces were evaluated using scanning electron microscopy (SEM). Data were analyzed via split-plot ANOVA and Tukey's test (α=0.05). RESULTS:Regardless of material, enamel KHN was lower at 20 µm than at 60 µm depth (100 µm distance), at 40 µm than at 60 µm depth (300 µm distance), and dentin KHN was also lower at 20 µm. RC and R-GIC showed reduced dentin KHN at 20 µm compared to 60 µm. SEM analysis revealed surface degradation in all materials (RC<R-GIC<FC<RC-S-PRG<RC-SP). CLINICAL SIGNIFICANCE:The ion-releasing bioactive materials did not provide superior protection of microhardness compared with the conventional composite. Moreover, bioactive materials exhibited greater surface degradation after acidic challenge, which may compromise their long-term stability in the oral environment.
PURPOSE:To evaluate the clinical efficacy of a test toothpaste containing 0.454% stannous fluoride stabilized with zinc phosphate as compared to a control fluoride toothpaste containing 0.76% sodium monofluorophosphate on oral malodor reduction via organoleptic scores after 3 weeks of twice daily product use. METHODS:A randomized, single-center, double-blind, parallel-group clinical trial conducted in Bangkok, Thailand. Eighty adult subjects with qualifying baseline oral malodor scores were randomized to use either the test toothpaste or the control toothpaste twice daily for 3 weeks. Efficacy was assessed using the organoleptic hedonic scale (1-9) by four calibrated judges. The primary endpoint was the reduction in organoleptic scores assessed 12 hours post-brushing (overnight). RESULTS:All 80 subjects completed the protocol. At baseline, there were no significant differences in organoleptic scores between groups (P= 0.816). After 3 weeks, the Test group showed a 37.8% reduction from baseline in overnight malodor scores (P< 0.001), while the Control group showed a 13.6% reduction (P< 0.001). The Test group demonstrated a statistically significant (P< 0.001) 28.0% greater reduction in oral malodor compared to the Control group. No adverse events were reported. CLINICAL SIGNIFICANCE:The 0.454% stannous fluoride toothpaste stabilized with zinc phosphate provided a superior, long-lasting solution for overnight oral malodor management compared to a standard sodium monofluorophosphate toothpaste after 3 weeks of use.
PURPOSE:To evaluate in the laboratory the effect of an in-office whitening agent on color change, translucency, and surface roughness of leucite-reinforced CAD-CAM material with different surface finishes exposed to different beverages [cola, tea, fruit juice, coffee, distilled water (Control)]. METHODS:All the IPS Empress CAD-CAM ceramic block specimens were treated with a glaze layer (n=75) and then randomly divided into three groups. The samples (n=25) in Group 1 (Control) were not treated (glaze layer remained). The glaze layer of the other samples (n=50) was abraded by the same researcher. While the samples in Group 2 were treated with Optrafine (Optrafine after glazing) (n=25), those in Group 3 were subjected to surface treatment with Eve polishing kits (Eve kit after glazing) (n=25). The samples were then immersed in five different beverages (cola, coffee, tea, fruit juice and distilled water) (n=5) and clinic-type bleaching was applied. Color measurements were recorded by spectrophotometer and surface roughness (Ra) values were recorded by profilometer. Color change (ΔE₀₀) values were calculated using the CIE2000 formula. The data were statistically analyzed using Shapiro-Wilk test, ANOVA and Bonferroni test (P< 0.05). RESULTS:Regardless of the surface finishing process and beverage, the mean values of color change (ΔE₀₀) did not differ according to time (P= 0.148). As a result of the ANOVA, surface finishing process, beverage, and time interaction were found to be very significant (P< 0.001). Regardless of the surface finishing process and beverage, it was determined that the mean roughness values differed according to time (P= 0.019). CLINICAL SIGNIFICANCE:Although bleaching glass ceramic restorations with bleaching agents containing 40% hydrogen peroxide was effective to remove stains, maintaining the glaze surface finish is critical for color stability and surface integrity of CAD-CAM ceramics.
PURPOSE:To investigate whether the amount of dentifrice (dose) used per brushing affects the abrasion of the hard tooth tissues. METHODS:Enamel and dentin specimens were subjected to simulated brushing with two commercial dentifrices (Prodent, Smyle dentifrice in tablet form) and positive as well as negative controls at varying amounts of dentifrices (standard dose, half, and double dose). Brushing without dentifrice (with water) functioned as a negative control. Tooth wear was quantified using profilometry, and statistical analysis was performed using one-way ANOVA and Tukey's post hoc test (α= 0.05). RESULTS:For enamel, dose variations had minimal impact. However, dentin wear increased significantly with higher doses, particularly for the positive control and Smyle at double dose (P< 0.05). Dilution reduced abrasivity inconsistently across brands. CLINICAL SIGNIFICANCE:The amount of dentifrice used for brushing has a significant, dose-dependent effect on dentin abrasion, whereas enamel is relatively unaffected, and brushing without dentifrice does not cause wear. While dentifrice in tablet form provides a manufacturer‑defined standard amount per brushing, this is not the case for dentifrice in paste form. Because the amount of dentifrice used influences dentin wear, it is advisable that manufacturers clearly define the recommended quantity of dentifrice for a single brushing.
PURPOSE:To evaluate the effect of faucet-mounted water filters (FMWF) on the fluoride and calcium concentrations in tap water during their use. METHODS:A convenience sample of 15 different brands of FMWF was investigated (PUR, Brita, Waterdrop, Culligan, Engdenton, DuPont, Instapure, iSpring, OEMIRY, IVO, SJ WAVE, WINGSOL, ZeroWater, AIBERLE, MIST). Water samples were collected before the installation and after removal of the filters to determine baseline fluoride and calcium values. After mounting the filters, samples were collected after 1, 5, 10, 30, 50, 75, and 100 liters of water passed through each filter. Fluoride analysis was performed using a fluoride ion-specific electrode (Orion #96-909-00), while calcium analysis was performed using atomic absorption spectrometry. The data were analyzed using one-sample t-tests and one-way ANOVA. RESULTS:The study found significantly lower fluoride and calcium levels (P< 0.05) in water filtered through PUR, Brita, and AIBERLE filters than in unfiltered water, whereas water filtered through Waterdrop, WINGSOL, and MIST filters had higher levels of fluoride and calcium. Overall, the differences between filtered and unfiltered water were minor for fluoride (up to 4% reduction) but more substantial for calcium (up to 25% reduction). CLINICAL SIGNIFICANCE:The evaluated faucet-mounted water filters do not affect fluoride concentrations in tap water and thus the effectiveness of community water fluoridation in a clinically significant manner; however, some filters may reduce calcium concentrations significantly.
PURPOSE:To evaluate the effects of different tooth structure thicknesses and cavity depths on the accuracy of intraoral scanners (IOS) in endocrown restorations. METHODS:A mandibular typodont model was used, with the left mandibular first molar replaced by an extracted real human tooth. Endocrown cavities with varying depths (3.5 mm and 5 mm) and remaining wall thicknesses (1.5 mm and 0.5 mm) were prepared. Master models were scanned using a high-precision extraoral scanner, and the data were exported in STL format. Ten intraoral scans were performed for each group using the TRIOS 3 IOS. Scanning accuracy was analyzed using the Root Mean Square (RMS) value for trueness and the Interquartile Range (IQR) for precision in Geomagic Design X software. The differences in RMS values among the groups were examined using Independent Samples T test and one-way ANOVA test. RESULTS:Significant differences in RMS and IQR values were observed between groups with different cavity depths and remaining tooth structure thicknesses (P< 0.001). Groups with thinner remaining tooth structures and deeper cavities exhibited greater deviations, indicating reduced scanning accuracy. CLINICAL SIGNIFICANCE:Cavity depth and tooth structure thickness significantly influenced the accuracy of intraoral scanners in endocrown restorations.
PURPOSE:This cross-sectional study was to assess the prevalence of acute PAs in fibromyalgia patients. METHODS:Nine years of data from 2,108,676 patients were retrieved and analyzed by searching corresponding ICD-10 diagnosis codes for fibromyalgia and acute PAs. The odds ratio (OR) for acute PAs and their association with fibromyalgia were calculated and statistically analyzed using MEDCALC software at the 95% confidence level. Logistic regression and adjustment for diabetes, nicotine dependence, and alcohol use disorder comorbidities were done. RESULTS:Overall, the OR for acute PAs in patients with fibromyalgia was 4.7, and the difference in prevalence compared to the total hospital patient population was statistically significant (P< 0.0001). After adjustment for diabetes, the OR was 2.8. After adjustment for nicotine dependence, the OR was 2.6. After adjustment for alcohol related disorders, the OR was 4.4. The difference in prevalence compared to the total hospital patient population remained statistically significant (P< 0.0001). CLINICAL SIGNIFICANCE:Clinicians should be aware of the possible higher prevalence of periapical abscesses in patients with fibromyalgia. More frequent dental visits for caries control and pulp disease prevention are warranted.
PURPOSE:To examine the effects of fiber post material and coronal preparation timing on the sealing ability of post-core systems and to determine whether these factors interact under thermal and mechanical aging conditions. METHODS:A 2×2 factorial design was used. 60 freshly extracted single-rooted premolars meeting predefined inclusion and exclusion criteria were randomly assigned to four groups (n= 15): fiber-reinforced composite (FRC) post with immediate preparation, FRC with delayed preparation, prefabricated quartz fiber (PQF) post with immediate preparation, and PQF with delayed preparation. Post space length was standardized to 10 mm while maintaining a 4 mm apical seal, in accordance with the recommendation that post length should approximate two-thirds of root length and at least equal the clinical crown height. All procedures were completed by a single prosthodontist. Specimens underwent 5,000 thermal cycles followed by 240,000 cyclic loading cycles. Interfacial microgap width was serially evaluated by SEM at two time points, namely after thermocycling and after cyclic loading, and the data were analyzed with a linear mixed-effects model. RESULTS:Post material type (F= 45.32, P< 0.001, η²p= 0.43) and time point (F= 312.56, P< 0.001, η²P= 0.84) showed significant effects, as did the material x time interaction (F= 8.73, P=0.004, η²P= 0.13). Preparation timing was not significant (F= 2.15, P= 0.148). After thermocycling, group B showed smaller microgap width than group D (3.91± 0.87 vs. 5.62± 1.77 µm; mean difference, -1.71 µm; 95%CI: -2.76 to -0.66; P=0.003). After cyclic loading, Group A was smaller than Group C (13.97± 1.89 vs. 17.85± 2.83 µm; mean difference, -3.88 µm; 95%CI: -5.62 to -2.14; P< 0.001), and Group B was smaller than group D (8.84± 1.98 vs. 13.29± 2.85 µm; mean difference, -4.45 µm; 95%CI: -6.22 to -2.68; P< 0.001). No root fractures were detected during specimen preparation, thermocycling, or cyclic loading. CLINICAL SIGNIFICANCE:For a given fiber post material, immediate and delayed coronal preparation produced comparable marginal sealing. Compared with prefabricated quartz fiber posts, fiber-reinforced composite post-core systems provided superior interfacial stability after aging and may be preferable in roots with irregular or flattened canal morphology.
PURPOSE:To evaluate the efficacy of a novel toothpaste formulation containing potassium phosphates, zinc chloride, and botanical extracts in managing periodontal conditions and dentin hypersensitivity. METHODS:A single-center, double-blind, randomized controlled trial was conducted over 4 weeks with 97 participants aged 30 years and older, all experiencing dentin hypersensitivity. Participants were randomly assigned to three groups: a negative control group using standard toothpaste, an experimental group using the test toothpaste with conventional brushing, and another experimental group using the test toothpaste with topical application followed by brushing. Efficacy was assessed by measuring plaque deposition with the Patient Hygiene Performance (PHP) Index, gingival health with the Gingival Index (GI) and the Papillary, Marginal, and Attached gingival inflammation index, and dentin hypersensitivity with an electric pulp tester (EPT). Statistical analyses were performed using SPSS version 25.5, with analysis of variance and paired t-tests to compare results across groups and time points. RESULTS:The topical application followed by brushing method (Group 3) demonstrated significantly greater efficacy in reducing dentin hypersensitivity, plaque accumulation, and gingival inflammation than both the control group and the conventional brushing group (Group 2). After 4 weeks, Group 3 demonstrated a 38.7% reduction in plaque index scores and a 50.8% reduction in GI scores, significantly outperforming the control group. For dentin hypersensitivity, Group 3 exhibited a 10.8% immediate desensitization effect, which was statistically significant compared with the control group. Questionnaire responses indicated higher satisfaction and perceived improvements in gingival health and sensitivity reduction in Group 3. These findings suggest that prolonging the contact time of active ingredients through delayed brushing enhances therapeutic outcomes for both dentin hypersensitivity and periodontal disease management. CLINICAL SIGNIFICANCE:The modified application method of the newly developed toothpaste exhibited significantly greater reductions in plaque accumulation, gingival inflammation, and dentin hypersensitivity than the control and conventional brushing methods.
PURPOSE:To evaluate the biofilm-forming potential of mixed-species bacteria on three commercially available dental restorative composites and compare their resistance to biofilm accumulation. Given the increasing emphasis on bioactive and fluoride-releasing materials in caries prevention, the study specifically assessed the difference between restorative with and without fluoride content. METHODS:Three restorative materials, Activa (bioactive fluoride releasing), Filtek Bulk Fill (non-fluoride releasing) and TPH (non-fluoride containing) were tested in the laboratory. Standardized resin-discs were fabricated, saliva-coated to simulate oral conditions, and inoculated with a 1:1 mixed culture of Streptococcus mutans and Lactobacillus casei. Biofilm development was assessed at 24- and 48-hours using colony forming unit (CFU) quantification. Statistical analysis was performed using one-way ANOVA and Tukey's post hoc test (α= 0.05). RESULTS:Significant differences in biofilm accumulation were observed among materials at both points (P< 0.05). TPH exhibited the highest CFU counts at 24 hours (0.24 ± 0.03 x 10⁷ CFU/mL) and 48 hours (1.07 ± 0.12 x 10⁷ CFU/mL). In contrast, Activa and Filtek showed significantly lower biofilm formation at both points (24 hours: 0.093 ± 0.05 x 10⁷ CFU/mL; 48 hours: 0.47 ± 0.31 and 0.53 ± 0.12 x 10⁷ CFU/mL, respectively), with no significant difference between them. CLINICAL SIGNIFICANCE:The restorative materials tested demonstrated varying degrees of resistance to biofilm formation. Activa and Filtek showed reduced biofilm accumulation compared to TPH at both early and mature stages of growth. The selection of restorative materials should consider their potential to resist bacterial colonization, especially in high-caries-risk patients and restorations placed near gingival margins.
PURPOSE:This randomized, controlled, crossover, and triple-blind clinical trial evaluated the antibiofilm action and patient acceptance of four experimental dentifrices with essential oils at 1%. METHODS:Participants (n= 24) selected based on eligibility criteria were randomly assigned to five groups: a positive control (chloramine T dentifrice), Melaleuca alternifolia (Ma), Pinus strobus (Ps), Bowdichia virgilioides Kunth (BvK), or Eucalyptus citriodora (Ec). They brushed their dentures three times/day with the provided brush and dentifrice for 14 days. A 7-day washout was established between each dentifrice use. Biofilm removal (computerized method), microbial load of Candida spp., Candida albicans, Candida tropicalis, Candida glabrata, Staphylococcus spp., Mutans streptococci, gram-negative bacteria, and total aerobes (colony-forming unit counting), cellular metabolism (XTT-assay), cell viability (flow cytometry), and patient satisfaction (questionnaire) were evaluated at baseline and after use of the dentifrices. Data were analyzed using Friedman's ANOVA and Cochran's Q Test for related samples (α= 0.05). RESULTS:The amount of biofilm (P= 0.004) and the microbial load of C. albicans (P= 0.003) were significantly lower after the use of the dentifrices compared to baseline. The dentifrices did not significantly affect cell viability (P= 0.170) or cellular metabolism (P= 0.814). No significant differences in patient acceptance were found between the experimental dentifrices and the positive control. Experimental dentifrices with 1% Melaleuca alternifolia, Pinus strobus, Bowdichia virgilioides Kunth, and Eucalyptus citriodora effectively cleaned dentures, reduced C. albicans load, and were well accepted by users. CLINICAL SIGNIFICANCE:Essential oil-based dentifrices effectively remove denture biofilm and reduce Candida albicans load, providing a natural and sustainable alternative to synthetic agents while being well accepted by users.
PURPOSE:To investigate the effects of herbal toothpastes compared to chemical toothpastes on restorative materials' structure and antimicrobial effects. METHODS:Four experimental herbal toothpastes and one chemical toothpaste (positive control group) were tested. Microhardness values, weights, and volumes of samples formed with dental composites were recorded before and after brushing. Minimal inhibitory concentration and agar well diffusion tests were used to evaluate the antimicrobial effect of toothpastes on contaminated surfaces. After brushing the samples with Streptococcus mutans plaque, colony counts were made as CFU/ml, and plaque inhibition was monitored by field emission scanning electron microscope (FE-SEM) examination. The data obtained were evaluated statistically. RESULTS:The study's results showed a statistically significant change in the microhardness, weight, and volume values of dental composites used in both the anterior and posterior regions. In the antimicrobial activity evaluation results, plaque inhibition was detected in the FE-SEM images of the composite blocks where herbal toothpastes were used. CLINICAL SIGNIFICANCE:The results showed a statistically significant change in the microhardness, weight, and volume values of dental composites used in both the anterior and posterior regions. In the antimicrobial activity evaluation results, plaque inhibition was detected in the field emission scanning electron microscope images of the composite blocks where herbal toothpastes were used.
PURPOSE:To evaluate the laboratory cleaning efficacy of six commonly used non-invasive methods for removing stains from occlusal fissures before caries diagnosis. METHODS:60 extracted, caries-free permanent molars with visible occlusal staining were divided into six groups (n= 10): AquaCare air abrasion, Kerr prophylactic paste, Whiteness HP (35% H₂O₂), HealOzone, oxygenated water + pumice, and Opalustre. All samples were analyzed pre- and post-treatment using a dental microscope, Diagnodent Pen, QLF imaging (Qraypen), 3D Geomagic Control X software for volumetric evaluation and photo editing software for pixel evaluation. Statistical analyses were performed with Kruskal-Wallis and the Friedman's two-way ANOVA test (P< 0.05). RESULTS:All methods significantly reduced surface discoloration (P< 0.05). AquaCare showed the least residual staining, while HealOzone had the highest (P= 0.043). Volumetric analysis revealed no intergroup enamel loss (P> 0.05), although a significant change was noted in the Whiteness HP group (P= 0.017). QLF parameters (ΔF and ΔQ) improved significantly in Aquacare, HealOzone, and Opalustre (P< 0.05). Diagnodent Pen readings decreased significantly in the Aquacare, Kerr paste, HealOzone, and oxygenated water + pumice groups (P< 0.05). All tested methods effectively removed fissure stains without causing measurable enamel loss. HealOzone, Aquacare, and Opalustre demonstrated the most balanced performance, combining high cleaning efficacy with minimal surface alteration. The findings emphasize the value of multimodal, minimally invasive approaches for optimizing diagnostic accuracy in occlusal fissure caries detection. CLINICAL SIGNIFICANCE:When making a caries indication, the staining of the fissures may affect the accuracy of the indication, but the most minimally invasive method should be preferred to clean the stained fissures.
PURPOSE:To compare the measurement results of different instrumental color analysis methods with a reference spectrophotometer. METHODS:Six different methods (DSLR camera and smartphone camera with and without cross-polarizing filter, VITA Easyshade and Spectroshade spectrophotometers) were evaluated using four different shade tabs (1M1, 3R2.5, 3L2.5, 5M3). X-Rite MetaVue VS3200, a highly repeatable spectrophotometer, was used as the reference method. All images were captured in RAW format using standardized lighting and white balance for photographic methods and analyzed using Adobe Photoshop. Beside the L*, a*, b* values, the ΔE₀₀ values were measured. Data was analyzed using one-way ANOVA and Tukey tests (P= 0.05). RESULTS:According to ANOVA test, the L*, a*, b* values of all groups showed significant differences for all shades (P< 0.05). When compared with the X-Rite MetaVue VS3200 group, the obtained ΔE₀₀ values also showed significant differences (P< 0.001) and were above the acceptability threshold. All ΔE₀₀ values were above the acceptability threshold (ΔE₀₀> 1.8) for all groups. The color measurement methods used in dental literature often produce inconsistent results when compared to each other. In this study, the results obtained from the tested methods were also inconsistent with the reference method. Therefore, the commonly used color measurement methods in dental research should be reconsidered. CLINICAL SIGNIFICANCE:Accurate tooth color determination relies on controlled lighting, geometry, and proper device calibration. This study demonstrated that variations among instrumental methods may exceed clinically acceptable limits, underscoring the importance of standardized measurement conditions. Clinicians should recognize that color analysis can differ between devices, even under identical settings, highlighting the significance of accurate color detection for optimal clinical outcomes.
PURPOSE:This systematic review and meta-analysis evaluated the effectiveness of locally delivered simvastatin and rosuvastatin in the treatment of chronic periodontitis. METHODS:A thorough literature review was performed utilizing PubMed, Scopus, Google Scholar, and ClinicalTrials.gov for studies published until June 2025. Titles, abstracts, and full texts of the eligible studies were obtained and reviewed. Data were subsequently extracted from the chosen studies and analyzed accordingly. RESULTS:A total of 30 RCT studies with 1,211 participants were included. Our study showed that the local delivery of simvastatin and rosuvastatin significantly improved pocket depth [Weighted Mean Difference (WMD) 95% confidence interval (CI)] = -0.83, -1.31 respectively, P< 0.001), clinical attachment level (-1.20, -1.59, P< 0.001), gingival index (-0.60, -1.42, P< 0.001), modified sulcus bleeding index (-0.61, -0.36, P< 0.001), plaque index (-0.38, P< 0.001), and relative attachment level (-0.54, -0.89, P< 0.001). However, there was no significant association between the plaque index and the use of rosuvastatin (-0.20, P< 0.05). CLINICAL SIGNIFICANCE:The local delivery of simvastatin and rosuvastatin along with scaling and root planing significantly reduced pocket depth and improved clinical attachment level, gingival index, modified sulcus bleeding index, and relative attachment level. Further clinical trials are still required to support the results of the current meta-analysis.
PURPOSE:To evaluate the impact of preheating on the physical properties of bulk-fill resin composites, with a particular focus on microhardness and surface roughness. METHODS:In this study, seven bulk-fill resin composites (SonicFill 3, Opus Bulk-Fill Flow, Opus Bulk-Fill, Metafil Bulk-Fill, Tetric PowerFlow, Tetric N-Ceram, and Estelite Bulk-Fill Flow) and one conventional resin composite (Filtek Z250) were tested. Specimens were divided into two main groups: Group 1 (preheated 68°C for 10 minutes) and Group 2 (stored at room temperature). For each group, five disc-shaped resin composites (4 mm thickness x 5 mm diameter) were prepared. Each bulk-fill resin composite was applied in a single increment, whereas Filtek Z250 was placed in the molds in 2 mm layers. To complete the polymerization, the samples were kept in distilled water at 37°C for 24 hours. Then, the surfaces of the samples were polished with Twist Dia (Clearfil) polishing discs to imitate the finishing and polishing processes. Baseline microhardness and surface roughness values were measured. Subsequently, specimens underwent artificial aging simulating 2 years of clinical use (10,000 brushing cycles + 1,200 thermal cycles). Post-aging measurements were repeated, and statistical analyses were conducted. RESULTS:Significant differences in microhardness values were observed among the experimental groups for all restorative materials, except for Estelite Bulk-Fill Flow (P> 0.05). The highest bottom-to-top hardness ratio was found in both preheated and non-preheated Opus Bulk-Fill Flow, while the lowest was observed in preheated Tetric PowerFlow. Microhardness generally decreased with depth, and the impact of preheating varied among materials. Post-aging surface roughness increased in all groups. Preheated Metafil Bulk-Fill exhibited the highest surface roughness, whereas Estelite Bulk-Fill Flow (both preheated and non-preheated) showed the lowest. Preheating reduced viscosity and enhanced microhardness in certain resin composites but also increased surface roughness over time. The effects of preheating are material-dependent due to compositional differences. CLINICAL SIGNIFICANCE:Preheating may improve handling and selected properties of resin composites; however, its long-term effects should be considered when selecting materials for clinical use.
PURPOSE:To assess how various surface treatment methods affect the repair shear bond strength (SBS) of flowable single-shade bulk-fill composite resins. METHODS:200 composite discs were fabricated using a nanohybrid composite (GrandioSo, VOCO) to simulate aged restorations. All specimens underwent 5,000 thermal cycles to mimic oral aging. Five different surface treatment approaches were tested: no treatment (control), diamond bur abrasion, phosphoric acid etching, Er,Cr:YSGG laser irradiation, and silane application. After treatment, three flowable single-shade bulk-fill composites: Omnichroma Flow Bulk (Tokuyama Dental), SimpliShade Bulk Fill Flow (Kerr), and Charisma Bulk Flow ONE (Kulzer) were bonded onto the aged surfaces using a universal adhesive (Tokuyama Universal Bond). SBS was measured with a universal testing machine, and failure modes were examined under a stereomicroscope. Statistical analyses were conducted with robust ANOVA and chi-square tests (α= 0.05). RESULTS:Both resin composite type and the surface treatment protocol, as well as their interaction, had significant effects on SBS values (P< 0.001). Among the tested groups, the highest SBS was recorded for GrandioSo combined with silane treatment (23.85 MPa), while the lowest was found for Charisma Bulk Flow ONE after acid etching (10.8 MPa). Silane application resulted in significantly greater SBS compared to other treatments (P< 0.001). Adhesive failures were most prevalent in the acid and control groups, whereas laser and silane groups displayed more cohesive and mixed failures. CLINICAL SIGNIFICANCE:Effective surface conditioning is essential for durable and predictable composite repairs. Silane application and Er,Cr:YSGG laser irradiation significantly improved the repair bond strength of flowable single-shade bulk-fill composites, whereas phosphoric acid etching alone was insufficient.
PURPOSE:The present study evaluated the enhanced antibacterial efficacy against Enterococcus faecalis (E. faecalis) of modified titanium dioxide (TiO₂) nanoparticles when combined with hydrogen peroxide (HP) and blue light irradiation. METHODS:Commercial pure TiO₂ was modified with polymer and copper to create polymer-copper-TiO₂ (pvpCT) nanoparticles. The optical property of pvpCT was characterized by absorbance measurements. Radical production was spectroscopically assayed using methylene blue (MB) degradation and terephthalic acid (TA) fluorescence. The antibacterial efficacy was then assessed against E. faecalis under blue light irradiation. RESULTS:Unlike pure TiO₂, pvpCT exhibited a distinct absorbance after 400 nm and presented a dark yellow visual appearance, indicating successful modification. The combined treatment of pvpCT, HP, and 405 nm laser irradiation resulted in significantly higher MB degradation and a strong fluorescence peak near 425 nm from the TA assay, outperforming HP-only (up to 15%) or laser-only treatments. Crucially, this synergistic condition (pvpCT+HP+blue light irradiation) also achieved a remarkable elimination of E. faecalis. These findings suggest that the combination of pvpCT, HP, and blue light irradiation represents a promising and effective strategy for advanced antibacterial treatment in dental applications. CLINICAL SIGNIFICANCE:Combined treatment of the polymer-combined-copper-coupled TiO₂, hydrogen peroxide, and blue laser irradiation can effectively eliminate oral bacteria, E. faecalis, through the reaction of hydroxyl radicals.
PURPOSE:To investigate the effect of sugar-free gum (SFG) with xylitol and sodium hexametaphosphate (SHMP) on oral cleansing by in vitro tests and a human clinical trial. METHODS:Hydroxyapatite (HA) discs were pre-treated with SHMP and evaluated for inhibition of stain formation caused by infusion of black tea in vitro. Subsequently, the effect of SFG formulated with different levels of SHMP was determined using a laboratory chewing apparatus to establish effective dosage of SHMP. Stain levels in both tests were assessed by colorimetry to determine L*, a*, b* values. Finally, a 12-week randomized, single blind, parallel arm human clinical study was performed to test effects of xylitol gum with SHMP on clinical indices of stain (Lobene Stain Index) and plaque (Plaque Index). 195 subjects were enrolled, with 181 subjects completing the trial. RESULTS:In vitro pre-treatment of HA discs with SHMP significantly inhibited tea-induced stain. Results from the chewing machine study showed that gums with SHMP significantly inhibited stain formation at 7 and 14 days, with a minimum effective level of 16.5 mg. The clinical study showed that SFG with 50% xylitol and 0.5% SHMP significantly inhibited plaque after 12 weeks compared with baseline and no-gum control (P< 0.05). The test gum also demonstrated a significant reduction of stain formation compared with baseline, no-gum control and commercial gum after 12 weeks (P< 0.05), reducing surface stain by 34% compared with baseline (P< 0.05). It was concluded that sugar-free gum containing xylitol and a low level of SHMP can provide an effective oral cleansing benefit, adjunctive to regular toothbrushing. CLINICAL SIGNIFICANCE:In addition to its well-recognized anticariogenic benefit, sugar-free gum formulated with xylitol and a low level of SHMP can also provide an effective oral cleansing benefit by helping control extrinsic tooth stain and plaque accumulation.
