Influence of Intravascular Laser Irradiation of Blood (ILIB) on inflammatory cytokines and nitric oxide in vivo: a systematic review.

The use of Intravascular Laser Irradiation of Blood (ILIB) as a treatment or adjunct tool has been used around the world since the 1980s. So that more professionals can deliver benefits to their patients in different areas of health, it is necessary to understand in depth the mechanisms of laser action at the molecular level, for correct indication and success in the treatment. To analyze works that evaluated the influence of ILIB on inflammatory cytokines and nitric oxide (NO) in animals and humans. The literature search was carried out between February and April 2023 in Pubmed, Medline, Web of Science, SciELO, Lilacs database. The risk of bias was assessed using the bias table where the authors performed the analyzes of all articles with the risk of bias domains. The methodology was defined following the PRISMA guidelines (Preferred Systematic Reviews and MetaAnalysis Report). The search retrieved 135 possibly relevant articles. After removing duplicates, according to the eligibility criteria, evaluation of titles and review of abstracts, in the end, 6 articles were included. An increase in anti-inflammatory cytokines, a decrease in pro-inflammatory cytokines and an increase in NO can be observed. The wavelengths used ranged from 660 to 808 nm when using a low intensity laser and when using a VIP light source 480-3400 nm, they also differed in terms of the light emission pattern. ILIB may be a complementary treatment option for patients who have comorbidities that lead to systemic inflammation.

Laser acupuncture to reduce temporomandibular disorder (TMD) symptoms: systematic review and meta-analysis.

The application of low-level laser therapy (LLLT) to acupuncture points may produce effects similar to that of needle stimulation in patients with temporomandibular disorders (TMD). This systematic review was conducted according to the Cochrane Collaboration guidelines and aimed to address clinical questions using the following strategy: Patient/Problem, Intervention, Comparison, and Outcome (PICO). A comprehensive literature search was performed upto April 26, 2023, across nine electronic databases (BVS, PubMed, Scopus, Embase, Web of Science, ScienceDirect, Cochrane Library, Latin American and Caribbean Health Sciences Literature (LILACS), and Google Scholar) supplemented with gray literature. The risk of bias in randomized and nonrandomized clinical trials was assessed using two tools: risk-of-bias (RoB) 2 and Risk Of Bias In Non-randomised Studies-of Interventions (ROBINS-I). Meta-analysis involved the extraction of mean and standard deviation values for spontaneous pain and mouth opening levels. Seven studies were included in this review, all of which used LLLT. The applied wavelengths ranged from 690 to 810 nm without significant variations in light emission patterns. LLLT demonstrated a significant reduction in instantaneous pain levels (standard mean difference [SMD] = 3.85; 95% confidence interval [CI] = 2.09, 5.62; p < 0.003) and an improvement in instantaneous mouth opening ability (mean difference [SMD] = -7.15; 95% CI = -11.73, -2.58; p < 0.002), with low certainty of evidence. LLLT may alleviate symptoms in patients with TMD; however, caution should be exercised when interpreting the results because of protocol variations among studies and the limited number of studies included in the meta-analysis.

Longevity of composite restorations in posterior teeth placed by dental students: a 12-year retrospective study.

OBJECTIVES: To evaluate the longevity of resin composite restorations placed in posterior teeth by dental students, using data from electronic records from 2008 to 2019. MATERIALS AND METHODS: Demographic (gender and age) and clinical variables (dental group, position in dental arch, and the number of restored surfaces) were evaluated. The 5-year follow-up was assessed according to the day the restoration was placed. Kaplan-Meier curves were generated to calculate the annual failure rate. Data were analyzed by Chi-Square, Kruskal-Wallis, and Mann-Whitney tests (α = 0.05). RESULTS: In total, 3.883 records relative to return periodicity were analyzed. The final sample consisted of 900 restorations from 479 patients. The majority were females, aged between 31 and 60. In total, 256 failures were reported (success rate = 78%), showing an annual failure rate of 2.05%. The main reasons for failures were restoration replacement (55.5%), endodontics (21.9%), prosthetics (14.5%) and extraction (8.2%). There was a higher risk of failure in restorations involving three or more surfaces (p = 0.000) and in patients over 60 years (p < 0.001). In females (p = 0.030), molars (p = 0.044), and maxillary teeth (p = 0.038) failed in a shorter time. CONCLUSIONS: Resin composite restorations placed in permanent posterior teeth by dental students had high survival rates. The main reason for failure was the replacement of restorations. The age group and the number of restored surfaces significantly affected the success of the restorations. CLINICAL RELEVANCE: The electronic health records over 12 years showed that 78% of the resin restorations in posterior teeth placed by dental students were successful for a minimum of five years.

Physicochemical and mechanical properties of preheated composite resins for luting ceramic laminates.

This study analyzed and compared the physicochemical and mechanical properties of preheated resin composite with light-cured resin cement for luting indirect restorations. 210 specimens of resin cement/resin composite were prepared according to preheating treatment heated (Htd) or not (NHtd). Light-cured resin cement (Variolink Veneer, Ivoclar), and resin composite (Microhybrid-Z100, 3 M; Nanohybrid-Empress direct, Ivoclar; and Bulk fill-Filtek One, 3 M) were used (n = 10). Resin cement specimens were not preheated. The response variables were (n = 10): film thickness, microhardness, liquid sorption and solubility. Data were analyzed by 2-way ANOVA and Tukey HSD post-test (α = 0.05). Bulk fill NHtd resin had the highest film thickness values (p < 0.001). Microhybrid and nanohybrid Htd resins had the smallest thicknesses and did not differ from the cement (p > 0.05). The highest microhardness values were found for Bulk fill NHtd and Bulk fill Htd resins. The nanohybrid and microhybrid Htd resins showed the lowest microhardness values, with no difference in cement (p > 0.05). For liquid sorption, there was no significant difference between the groups (p = 0.1941). The microhybrid Htd resin showed higher solubility values than the other materials (p = 0.0023), but it did not differ statistically from resin cement (p > 0.05). Preheating composite resins reduced the film thickness. After heating, nanohybrid and Bulk fill resins retained stable microhardness, sorption, and solubility values.

Effect of low-level laser stimulation of acupuncture points in pediatric dentistry: a systematic review.

The biomodulatory potential of low-level laser therapy (LLLT) has prompted investigations of different outcomes in health. One line of research is the stimulation of acupuncture points for the relief of different signs and symptoms related to the stomatognathic system. In dentistry, some studies in pediatric dentistry have demonstrated the benefit of LLLT therapies in the management of dental anxiety in children. This systematic review aimed to analyze previous clinical studies on the application of LLLT at acupoints among pediatric dental patients. This systematic review was conducted according to the Cochrane Collaboration guidelines and the population, intervention, comparison, and outcome strategy. A broad literature search up to June 17, 2022, was performed using four electronic databases (PubMed, Scopus, Embase, and Google Scholar). The risk of bias in randomized clinical trials was assessed using the RoB 2 tool. A total of four studies using LLLT for photobiomodulation were included (n = 4). The most common wavelengths used were in the infrared range (variation between 716 nm and 980 nm). There were little variations in the application time (14 s to 1 min) and exposure dose (1 to 5 joules). LLLT acted positively on different acupuncture points. LLLT provided various benefits and optimized dental practice by reducing the gag reflex during radiography and impression taking, preanesthetic pain, and symptoms of sleep bruxism in the pediatric dental population. Only one of the evaluated studies had a high risk of bias. The LLLT at acupuncture points is associated with positive results on sleep bruxism, preanesthetic pain, and gag reflex in pediatric dentistry. Future research studies should prioritize standardization of the study design and the methods of analysis.

Laser acupuncture in the treatment of neuropathies in dentistry: a systematic review.

Laser acupuncture can be used to treat neurosensory alterations and motor disorders caused by dental treatments. This study aimed to review the existing literature on the effects of laser acupuncture on neuropathies in the context of dentistry and to search for treatment modalities in which this technique is used. This systematic review was conducted in accordance with the Cochrane Collaboration guidelines and the PICOS strategy. Randomized clinical trials that evaluated laser acupuncture as a primary intervention for facial neuropathy were included. We searched the database for relevant studies and manually searched the gray literature until April 2022, and finally included four studies. The study was considered eligible if it included patients with paresthesia, facial paralysis, or neuralgia, neuropathies within dentistry, and referred to the application of laser acupuncture as a treatment method. The risk of bias was assessed using the RoB 2 tool. It was observed that the recommended wavelengths ranged from 790 nm to 810 nm, with a frequency of at least two applications per week, and to a greater or lesser degree, all evaluated studies obtained an improvement in sensory or motor recovery of the facial nerves. The use of laser acupuncture presented itself as a viable alternative in dentistry for the treatment of paresthesia and facial paralysis due to its therapeutic potential in neuropathic treatment (CRD42022344339).

Do erbium lasers promote changes in the tooth enamel during debonding of ceramic laminate veneers? A systematic review.

The longevity of ceramic laminate veneers can be influenced by several factors, which can result in the need for a removal process. Laser removal has emerged as a good alternative to facilitate the procedure, and its repercussions on tooth enamel have been investigated. We aimed to evaluate the efficacy of erbium lasers for debonding ceramic laminate veneers without damaging the tooth enamel. This systematic review based on the PICOS model adhered to the PRISMA statement. The PubMed/MEDLINE, Web of Science, Embase, and Scopus databases were systematically searched until December 1, 2022, and 2902 studies were retrieved. After screening, four in vitro studies that analyzed the dental morphology using scanning electron microscopy, optical analysis, stereomicroscopy, or x-ray dispersion spectroscopy were included. The risk of bias was assessed using the Cochrane Collaboration tool. Our findings suggest that erbium lasers are useful for ceramic laminate veneer removal without damaging the tooth enamel. However, the removal is influenced by the type and thickness of ceramic and type of cement used. It could be concluded that the application of Erbium laser did not promote superficial changes in the dental enamel. This effect was observed in all analysis performed.

In vitro antibacterial activity of green tea-loaded chitosan nanoparticles on caries-related microorganisms and dentin after Er:YAG laser caries removal.

This study aimed to determine the inhibitory effects of green tea (Gt), EGCG, and nanoformulations containing chitosan (Nchi) and chitosan+green tea (Nchi+Gt) against Streptococcus mutans and Lactobacillus casei. In addition, the antibacterial effect of nanoformulations was evaluated directly on dentin after the selective removal of carious lesion. At first, the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) against S. mutans and L. casei isolates were investigated. In parallel, dentin specimens were exposed to S. mutans to induce carious lesions. Soft dentin was selectively removed by Er:YAG laser (n=33) or bur (n=33). Remaining dentin was biomodified with Nchi (n=11) or Gt+Nchi (n=11). Control group (n=11) did not receive any treatment. Dentin scraps were collected at three time points. Microbiological analyses were conducted and evaluated by agar plate counts. Gt at 1:32 dilution inhibited S. mutans growth while 1:16 was efficient against L. casei. EGCG at 1:4 dilution completely inhibited S. mutans and L. casei growth. Independently of the association with Gt, Nchi completely inhibited S. mutans at 1:4 dilution. For L. casei, different concentrations of Nchi (1:32) and Nchi+Gt (1:8) were required to inhibit cell growth. After selective carious removal, viability of S. mutans decreased (p<0.001), without difference between bur and Er:YAG laser (p>0.05). Treatment with Nchi and Nchi+Gt did not influence the microbial load of S. mutans on dentin (p>0.05). Although variations in concentrations were noticed, all compounds showed antibacterial activity against S. mutans and L. casei. Both bur and Er:YAG laser have effectively removed soft dentin and reduced S. mutans counts. Nanoformulations did not promote any additional antibacterial effect in the remaining dentin.

Er:YAG laser in selective caries removal and dentin treatment with chitosan: a randomized clinical trial in primary molars.

This study evaluated the effect of chitosan on dentin treatment after selective removal of caries lesions with Er:YAG laser in reducing Streptococcus mutans, as well as its effect on the performed restorations. The sample consisted of children (aged 7 to 9 years) with active carious lesions and dentin cavitation located on the occlusal surface of deciduous molars. Eighty teeth were randomly distributed into 4 groups according to the caries removal method: Er:YAG laser (250 mJ/4 Hz) or bur and dentin surface treatment: 2.5% chitosan solution or distilled water. The bacterial load of caries-affected dentin was quantified by counting CFU/mg (n = 10). The teeth were restored and evaluated at 7 days, 6 months, and 12 months using modified USPHS criteria (n = 20). Microbiological data was analyzed by Mann-Whitney and clinical analyses were done using Kruskal-Wallis and Dunn test (α = 0.05). The results showed that the Er:YAG laser significantly reduced the amount of Streptococcus mutans (p = 0.0068). After dentin treatment with chitosan, there was a significant reduction in the amount of Streptococcus mutans for both removal methods (p = 0.0424). For the retention and secondary caries criteria, no significant differences were observed along the evaluated time (p > 0.05). The laser-treated group was rated "bravo" for discoloration (p = 0.0089) and marginal adaptation (p = 0.0003) after 6 and 12 months compared to baseline. The Er:YAG laser reduced the amount of Streptococcus mutans and the chitosan showed an additional antibacterial effect. After 1 year, the Er:YAG laser-prepared teeth, regardless of the dentin treatment, showed greater discoloration and marginal adaptation of the restorations.

Effects of the green tea catechin epigallocatechin-3-gallate on Streptococcus mutans planktonic cultures and biofilms: systematic literature review of in vitro studies.

This study aimed at performing a systematic review of the literature on the effects of epigallocatechin-3-gallate (EGCG) on Streptococcus mutans planktonic cultures and biofilms. The selected references demonstrated that EGCG suppresses S. mutans acid production by inhibiting the activity of enzymes such as lactate dehydrogenase and FIF0-ATPase. Regarding virulence factors, one study reported a reduction in soluble and insoluble polysaccharide synthesis, another demonstrated that EGCG inhibited GTase activity, and another showed effects of EGCG on the expression of gtf B, C, and D. The effects of EGCG on S. mutans biofilms were reported only by 2 of the selected studies. Moreover, high variability in effective concentrations and microbial assessment methods were observed. The literature suggests that EGCG has effects against S. mutans planktonic cells viability and virulence factors. However, the literature lacks studies with appropriate biofilm models to evaluate the precise effectiveness of EGCG against S. mutans biofilms.

Photoinactivation of multispecies cariogenic biofilm mediated by aluminum phthalocyanine chloride encapsulated in chitosan nanoparticles.

This study aimed to characterize the aluminum phthalocyanine chloride (AlClPc) encapsulated in chitosan nanoparticles (CN) and apply it in antimicrobial photodynamic therapy (aPDT) on multispecies biofilm composed of Streptococcus mutans, Lactobacillus casei, and Candida albicans to analyze the antimicrobial activity and lactate production after treatment. Biofilms were formed in 24-well polystyrene plates at 37 °C for 48 h under microaerophilia. The following groups were evaluated (n = 9): as a positive control, 0.12% chlorhexidine gluconate (CHX); phosphate-buffered saline (PBS) as a negative control; 2.5% CN as release vehicle control; the dark toxicity control of the formulations used (AlClPc and AlClPc + CN) was verified in the absence of light; for aPDT, after 30 min incubation time, the photosensitizers at a final concentration of 5.8 × 10-3 mg/mL were photoirradiated for 1 min by visible light using a LED device (AlClPc + L and AlClPc + CN + L) with 660 nm at the energy density of 100 J/cm2. An in vitro kit was used to measure lactate. The biofilm composition and morphology were observed by scanning electron microscopy (SEM). The antimicrobial activity was analyzed by quantifying colony forming units per mL (CFU/mL) of each microorganism. Bacterial load between groups was analyzed by ANOVA and Tukey HSD tests (α = 0.05). A lower lactate dosage was observed in the aPDT AlClPc + CN + L and CHX groups compared to the CN and AlClPc groups. The aPDT mediated by the nanoconjugate AlClPc + CN + L showed a significant reduction in the viability of S. mutans (3.18 log10 CFU/mL), L. casei (4.91 log10 CFU/mL), and C. albicans (2.09 log10 CFU/mL) compared to the negative control PBS (p < 0.05). aPDT using isolated AlClPc was similar to PBS to the three microorganisms (p > 0.05). The aPDT mediated by the nanoconjugate AlClPc + CN + L was efficient against the biofilm of S. mutans, L. casei, and C. albicans.

Photobiomodulation impacts the levels of inflammatory mediators during orthodontic tooth movement? A systematic review with meta-analysis.

During orthodontic tooth movement (OTM), there is the release of cytokines in the gingival crevicular fluid (GCF) that are supposed to participate in the bone remodeling. This systematic review aimed at assessing the effects of photobiomodulation (PBM) on the levels of these cytokines during OTM. This systematic review according to Cochrane Collaboration guidelines aimed to answer the clinical question following the PICOS strategy. The broad search in the literature was performed before 05 April, 2021 in six electronic databases (Pubmed, Web of Science, Scopus, Embase, Cochrane, Biblioteca Virtual de Saúde) and supplemented by the grey literature. The risk of bias of randomized and non-randomized clinical trials was evaluated by two tools: RoB 2 and ROBINS-I. Mean and standard deviation of cytokine levels was extracted to meta-analysis, and the GRADE system was applied to assess the quality of the evidence. Nine studies were included in this review. Low-level laser therapy (LLLT) was the photobiomodulation type used in most of the studies (n = 8). The wavelengths used varied from 618 to 980 nm and also differed concerning the light emission pattern. LLLT increased the levels of IL-1ß, IL-8, OPN, and PGE2, but not TNF-α1, TGF-ß1. The levels of IL6, RANKL, and OPG presented conflicting results. LLLT was statistically associated with an increase of IL-1ß levels (standard mean difference [SMD] = 1.99; 95% confidence interval = 0.66 to 3.33; p < 0.001) with low certainty of evidence. LLLT may increase the levels of IL-1ß and other cytokines; however, the results should be interpreted with caution due to protocol variations between studies, and the few studies added in the meta-analysis.

The COVID-19 outbreak on dental practice in State of São Paulo, Brazil.

Brazil has become the epicenter of coronavirus disease, and the São Paulo State has the worst scenario. This study evaluated the effect of the COVID-19 in dentists of São Paulo State, Brazil. A self-administered web-based survey with 33 multiple-choice questions was sent to dentists. Descriptive statistics were used to assess the 302 valid responses. Data were analyzed by Chi-square, McNemar and Wilcoxon tests (α = 0.05). Most of the participants aged until 34 years (61.6%) and were female (74.5%). They reduced work to less than 20 h per week. Monthly remuneration was reduced (86.8%). Personal protective equipment at the office was changed (p < 0.05). A few dentists (7.6%) had COVID-19, and more than 99% were aware of the disease. Most of the participants (90.2%) were insecure about being contaminated. The dentists of São Paulo State had coronavirus knowledge and have adopted strict biosafety protocols, but the pandemic affected their financial and psychological features.

Brazilian dental students and COVID-19: A survey on knowledge and perceptions.

OBJECTIVE: This study evaluated the knowledge and perceptions of Brazilian dental students about COVID-19 and the undergraduate clinical practice during the COVID-19 outbreak by a self-administered Web-based questionnaire. METHODS: A social network campaign on Instagram was raised to approach the target population. The survey covered demographic and academic profile, general knowledge, preventive measures and perception about COVID-19. Descriptive statistics were used to identify frequencies and distributions of variables, which were compared by type of institution and current year of enrolment using the Chi-square or Fisher's exact tests (α = 0.05). RESULTS: A total of 833 valid responses were received over 10 days. Students were able to identify the incubation period, main symptoms and contagious routes of the disease but struggled in recognising the name of the virus responsible for the pandemic. Hand washing before and after a dental appointment with a patient (97.7%) followed by the use of barriers to protect mucosa (97.2%) were the more frequently recognised measures to prevent COVID-19 spread in the dental office. As for the perception of COVID-19, 73.2% of the dental students perceived the disease as severe, whilst only 11.1% of them thought that COVID-19 is severe only for people presenting risk factors. Dental student's knowledge and perception were associated with the type of institution and year of enrolment. CONCLUSION: In summary, the dental students demonstrated an acceptable general knowledge about COVID-19, but dental schools will need to address gaps in knowledge, preventive measures, and perceptions to ensure a safer return to in person activities.

Influence of nanoparticulated chitosan on the biomodification of eroded dentin: clinical and photographic longitudinal analysis of restorations.

To evaluate the influence of the pre-treatment with 2.5% nanoparticulate chitosan (2.5% NanoChi) solution on eroded dentin before the restorative dental treatment. The sample consisted of 22 patients (age between 33 and 52 years) with shallow or medium erosion lesions located in two homologous teeth. The teeth were randomly assigned according to dentin treatment: with 2.5% NanoChi and without with chitosan (control). The NanoChi were applied immediately after acid etching. The teeth were restored with Single Bond Universal (3 M) and Charisma resin (Kulzer). Analyzes were done using modified USPHS (retention, secondary caries, marginal adaptation, and sensitivity) and photographic (color, marginal pigmentation, and anatomical form) criteria at 7 days (baseline) and 1 year. Population demographics, Kaplan-Meier estimates and log-rank test (Mantel-Cox) were calculated for 1 year (α = 0.05). No significant difference was found in the survival rates between groups (p > 0.05) at 7 days and 1 year after treatment. After 7 days, 100% of the restorations were scored as Alpha on all criteria. After 1 year, 91% of the NanoChi restorations were scored as Alpha and 9% as Charlie for the retention, marginal adaptation, and anatomical form criteria, while 86% of the control restorations (without NanoChi) received the Alpha score and 14% received the Charlie. Secondary caries, sensitivity, color, and marginal pigmentation criteria were scored as Alpha in 100% of the restorations. The biomodification of eroded dentin with 2.5% NanoChi did not influence the survival of the restorations after 1 year. The application of 2.5% NanoChi on eroded dentin did not increase failures of resin restorations after 1 year and it can be used as a pre-treatment solution.

Effect of green tea-loaded chitosan nanoparticles on leathery dentin microhardness.

The purpose of this study was to assess the effect of a chitosan-based nanoformulation containing green tea on leathery (remaining) dentin subsurface microhardness. Size distribution, polydispersity index (PDI) and zeta potential (mV) of nanoformulations were previously determined by dynamic light scattering (DLS). Human dentin specimens were exposed to Streptococcus mutans for 14 d. Soft dentin were selectively removed by Er:YAG laser (n = 30) or bur (n = 30). Remaining dentin was biomodified with chitosan nanoparticles (Nchi, n = 10) or green tea-loaded chitosan nanoparticles (Gt + Nchi, n = 10) for 1 min. Control group (n = 10) did not receive any treatment. Subsurface microhardness (Knoop) was evaluated in hard (sound) and soft dentin, and then, in leathery dentin and after its biomodification, at depths of 30, 60 and 90 µm from the surface. Nchi reached an average size of ≤ 300 nm, PDI varied between 0.311 and 0.422, and zeta potential around + 30 mV. Gt + Nchi reached an average size of ≤ 350 nm, PDI < 0.45, and zeta potential around + 40 mV. Soft dentin showed significantly reduced microhardness at all depths (p > 0.05). The subsurface microhardness was independent of choice of excavation method (p > 0.05). At 30 µm from the surface, Gt + Nchi increased the leathery dentin microhardness compared to untreated group (p < 0.05). Nchi promoted intermediate values (p > 0.05). Both nanoformulations showed an average size less than 350 nm with nanoparticles of different sizes and stability along the 90-day period evaluated. Subsurface microhardness of bur-treated and laser-irradiated dentin was similar. At 30 µm, the biomodification with Gt + Nchi improved the microhardness of leathery dentin, independently of caries excavation method used.

Efficacy of CO lasers in preventing dental caries in partially erupted first permanent molars: a randomized 18-month clinical trial.

The aim of this controlled randomized double-blinded clinical trial was to evaluate the use of a CO2 laser with or without topical application of acidulated fluorides in the prevention of dental caries in partially erupted first permanent molars. We selected 61 healthy children at high risk of caries, all between 6 and 8 (7.1 ± 0.8) years of age and with 4 partially erupted first permanent molars. A CO2 laser device emitting at 10.6 µm was used (0.5 W, 0.05 mJ per pulse, 10 kHz). Each first molar in an individual was randomly assigned to one treatment: (L) CO2 laser (0.066 J/cm2); (FL) 1.23% acidulated fluoride gel and CO2 laser (0.066 J/cm2); (V) 5% fluoride varnish, or (S) sealant (control). Patients were followed-up at 3, 6, 12, and 18 months after treatment, through direct visual examination and by an operator blinded to the treatments (kappa ≥ 0.70). The International Caries Detection and Assessment System (ICDAS-II) index was used to assess the soundness of tooth structure or the presence of white spot lesions, cavitated enamel, and/or dentin lesions. The Yildiz Visual Index was used to evaluate sealant retention. Results were evaluated using Kaplan-Meier survival analysis, and the hazard ratio of the treatments was estimated using shared frailty models with a gamma distribution, which considered the patient as a cluster. There were no significant differences among treatments compared to sealants. After 18 months, the use of a CO2 laser with or without acidulated fluorides was shown to be effective in preventing caries on the occlusal surface of partially erupted permanent first molars in children at high risk for caries.

Four-year clinical prospective follow-up of resin composite restoration after selective caries removal using Er:YAG laser.

OBJECTIVES: The aim of this study was to longitudinally evaluate, after a 4-year period, the clinical longevity of composite resin restoration compared to the baseline, after selective caries removal in permanent molars using Er:YAG laser or bur preparation with biomodification of dentin with the use of chlorhexidine. METHODS: Selective caries removal was performed on 80 teeth of 20 individuals who each had at least four active carious lesions. These lesions, located on occlusal surfaces of permanent molar counterparts, were removed using (i) Er:YAG laser biomodified with chlorhexidine, (ii) Er:YAG laser and application of deionized water, (iii) bur preparation biomodified with chlorhexidine, and (iv) bur preparation and application of deionized water. At the end of 4 years, 64 of the 80 restorations were evaluated in 16 individuals (n = 16). The restorations were evaluated, both clinically and photographically, using scanning electron microscopy (SEM) and pulp vitality analysis. The experimental data were statistically evaluated by kappa, Fisher's, and chi-square tests, with a significance level of 5%. The Kaplan-Meier test and the Cox regression analysis were used to evaluate the survival of the restorations. RESULTS: After 4 years of follow-up, there was a statistically significant difference in marginal discoloration criteria for all of the groups evaluated. For marginal adaptation criteria, there was a statistically significant difference for the Er:YAG laser group biomodified with chlorhexine (p = 0.050). For clinical and radiographic evaluation of pulp vitality, there were no statistically significant differences among the groups (p = 0.806). CONCLUSION: Er:YAG laser can be used for selective caries removal, regardless of dentin biomodification with chlorhexidine or application of deionized water, once it produced promising results in composite resin restorations after 4 years of follow-up, according to the criteria evaluated. The selective caries removal using Er:YAG laser or bur and the biomodification of dentin with the use of chlorhexidine did not influence the survival of composite resin restorations after the 4-year follow-up period. CLINICAL RELEVANCE: Composite resin restorations applied after selective caries removal using Er:YAG laser or burs, regardless of dentin biomodification with the use of chlorhexidine or application of deionized water, showed adequate clinical behavior after 4 years of follow-up.

Dentin pretreatment with Er:YAG laser and sodium ascorbate to improve the bond strength of glass fiber post.

Root-filled teeth that received fiber posts most frequently fail at the adhesive interface between resin cement and dentin. The objective of this study is to evaluate the effect of Er:YAG laser and/or sodium ascorbate (SA) on bond strength, microhardness of dentin, and penetration depth of cement into dentinal tubules. Forty-eight bovine incisor roots were endodontically treated, post spaces were prepared and equally divided into four groups (n = 12): G1-distilled water (control); G2-10% SA (10 min); G3-Er:YAG laser (150 mJ/4 Hz/40 s), and G4-Er:YAG laser + 10% SA. Glass fiber posts were cemented and roots sectioned into slices. In the first slice, the push-out bond strength (MPa) and failures were analyzed by confocal laser scanning microscope (CLSM). The second slice was subjected to microhardness test (KHN) and CLSM to assess the cement penetration. ANOVA and Tukey test were used for bond strength and microhardness data and Kruskal-Wallis and Dunn tests for the cement penetration (α = .05). The SA-treated samples had higher bond strength (10.02 ± 5.45a), similar to Er:YAG laser (9.91 ± 4.62a) and Er:YAG laser + SA (8.09 ± 4.07a). The least values (P < .05) were found on control (4.02 ± 2.39b). Significant differences were observed on root thirds (P < .05): cervical > middle > apical. There was a predominance of adhesive failures. The microhardness test revealed no differences between groups (P > .05). The experimental groups (G2, G3, and G4) had highest penetration into dentinal tubules when compared to the control (G1). Dentin pretreatments with Er:YAG laser or SA improved bond strength of cement-post-dentin interfaces; however, no synergistic effect of both treatments combined was observed.