Association of Papacarie Duo® and low-level laser in antimicrobial photodynamic therapy (aPDT).

Dental caries is a multifactorial, non-communicable disease. Effective treatment options for minimally invasive removal of carious tissue include Papacarie Duo® gel and antimicrobial photodynamic therapy (aPDT). aPDT involves a combination of a light source and photosensitizer. Given that Papacarie Duo® contains a percentage of blue dye, this study aims to explore the antimicrobial potential of Papacarie Duo® when associated with a light source against Streptococcus mutans strains. The chosen light source was a low-power diode laser (λ = 660 nm, E = 3 J, P = 100 mW, t = 30 s). To assess antimicrobial capacity, planktonic suspensions of Streptococcus mutans were plated on Brain Heart Infusion Agar (BHI) to observe the formation of inhibition halos. The studied groups included methylene blue (0.005%), Papacarie Duo®, distilled water (negative control), 2% chlorhexidine (positive control), Papacarie Duo® + laser, and methylene blue (0.005%) + laser. Following distribution onto plates, each group was incubated at 37 °C for 48 h under microaerophilic conditions. Inhibition halos were subsequently measured using a digital caliper. The results showed that chlorhexidine had the greatest antimicrobial effect followed by the group of irradiated methylene blue and irradiated Papacarie Duo®. All experimental groups demonstrated antimicrobial potential, excluding the negative control group. The study concludes that Papacarie Duo® exhibits antimicrobial properties when associated with a low-power diode laser.

Osteoinductive activity of photobiomodulation in an organotypic bone model.

Photobiomodulation (PBM) is a technique that harnesses non-ionizing light at specific wavelengths, triggering the modulation of metabolic pathways, engendering favourable biological outcomes that reduce inflammation and foster enhanced tissue healing and regeneration. PBM holds significant promise for bone tissue applications due to its non-invasive nature and ability to stimulate cellular activity and vascularization within the healing framework. Notwithstanding, the impact of PBM on bone functionality remains largely undisclosed, particularly in the absence of influencing factors such as pathologies or regenerative therapies. This study aims to investigate the potential effects of PBM using red (660 nm) (RED) and near-infrared (808 nm) (NIR) wavelengths within an ex vivo bone culture system - the organotypic embryonic chicken femur model. A continuous irradiation mode was used, administering a total energy dose of 1.0 J, at an intensity of 100 mW for 10 s, which was repeated four times over the course of the 11-day culture period. The primary focus is on characterizing the expression of pivotal osteoblastic genes, the maturation and deposition of collagen, and the formation of bone mineral. Exposing femora to both RED and NIR wavelengths led to a notable increase in the expression of osteochondrogenic transcription factors (i.e., SOX9 and RUNX2), correlating with enhanced mineralization. Notably, NIR irradiation further elevated the expression of bone matrix-related genes and fostered enhanced deposition and maturation of fibrillar collagen. This study demonstrates that PBM has the potential to enhance osteogenic functionality within a translational organotypic bone culture system, with the NIR wavelength showing remarkable capabilities in augmenting the formation and maturation of the collagenous matrix.

Clinical Evaluation of Bilateral Multiple Gingival Recession Treatment with Autogenous Connective Tissue Graft Associated with Low-Level Laser Therapy.

BACKGROUND: Gingival recession (GR) is described as an apical displacement of the gingival margin in relation to the cementoenamel junction, exposing the root surface to the oral cavity environment. This study aimed to evaluate the clinical results of a bilateral root coverage (RC) of GR associated with an autogenous connective tissue graft (aCTG) alone or combined with low-level laser therapy (aCTG + LLLT). METHODS: This cross-sectional, split-mouth, double-blind, clinical pilot study featured three individuals who attended a periodontics post-graduate program with the main complaint of GR and dental hypersensitivity (DHS). Of these, only one patient met the inclusion criteria and the parameters evaluated were: DHS, the keratinized tissue's thickness and width clinical attachment level (CAL), probing on depth (PD), and bilateral GR based on Cairo RT I. The patient was evaluated by a first clinical evaluator and the treatment was randomly divided into two groups, G1: aCTG only (control group, n = 3 teeth per side) and G2: aCTG + LLLT (test group, n = 3 teeth per side). LLLT used a diode laser (660 nm) with a dose of 3 J/cm2 per point and 4 s per point was applied in four different periods, preoperatively; transoperatively and immediately postoperatively, the application was performed in three points (eight applications) on alternate days for 7 days and a 90-day follow-up was performed for clinical evaluations of the periodontal parameters and the collected data were analyzed by Kruskal-Wallis and Dunn tests. RESULTS: the RC mean percentage was <95% in both groups after 90 days. Comparing treatment sides, G1 (n = 3/3, 100%) had a higher prevalence of RC than G2 had (n = 3/3, 95%). DHS significantly decreased after 90 days in both groups. Both groups showed an improvement in the other periodontal parameters evaluated during the short-term follow-up; mainly, PD had a statistically significant (p ˂ 0.05) increase after 90 days and a CAL decrease during this period; KTW and KTT also had a significant increase in both groups (p ˂ 0.05). CONCLUSIONS: the results indicated that aCTG + LLLT might have an additional benefit to GR root coverage within the evaluated time and this section also includes the within-study limitations.

Photobiomodulation in Pain Control in Diseases of the Oral Cavity: Overview (Evidence Map) and Its Implementation in Integrative Complementary Medicine.

Objective: To assess the evidence available and knowledge gaps in photobiomodulation (PBM) for oral facial pain. Background data: Effective identification of a noninvasive resource for oral facial pain such as PBM may mitigate the risks of invasive therapeutic resources. Methods: Nine electronic databases were searched for systematic reviews reporting oral facial pain outcome for PBM. The 3iE (International Initiative for Impact Evaluation) evidence gap map methodology with the tableau was used to graphically display the parameters analyzed in the research. Results: Several wavelengths within the range of infrared were used in 37.6% of the studies, accompanied by the 32.4% in the red range. The quality of the effect was positive in 61.4% of the studies, whereas the impact degree was low, according to the measurement tool used to assess systematic reviews 2 (AMSTAR 2), in 60.2%. Conclusions: Despite the positive potential of PBM in the treatment and control of pain in diseases of the oral cavity, complete information on dosimetry in published studies with PBM is still lacking, making it difficult to reproduce the results found.

Comparison of Bichectomy Techniques Through a Clinical Case and 6-Month Follow-up.

Introduction: Bichectomy consists in the partial removal the Bichat ball (BB) of its buccal extension and smoothing the facial contour. The objective of this study is to present, by means of a clinical case, bichectomy surgery with the use of a high-power diode laser and cold scalpel on different sides of the same patient, analyzing the trans-surgical phase and the pain and edema like consequence operative of each technique and 6-month follow-up. Case Presentation: A 20-year-old female patient reported the occurrence of involuntary trauma to the cheek mucosa and rounded facial appearance. After anamnesis and clinical examination, bichectomy was proposed. For comparison, on the right side, an incision was made using a laser, while on the left side, with a cold scalpel. To assess and measure the progression of treatment, photographs and facial measurements were repeated before the procedure, 7, 14 and 28 days after the procedure, and 2, 3 and 6 months after the procedure. Conclusion: The high-power diode laser showed excellent applicability for bichectomy due to its hemostatic properties in the trans-surgical phase. In addition, it promoted greater patient comfort, with less edema and pain on the side of the face where it was used.

Violet led dental whitening: Effectiveness and biological safety: An in vitro study.

INTRODUCTION: The light-emitting diode (Led) in the violet spectrum associated or not with hydrogen peroxide (HP) has been suggested as a promising technique for dental bleaching. Violet led has a wavelength of 405-410 nm, which is very close to that of ultraviolet (UV) radiation, and this has raised biological safety concerns. AIM: To investigate the effectiveness of the violet led dental bleaching technique by evaluating color parameters, enamel surface microhardness, and biological safety analysis. METHODS: One hundred bovine dental blocks were divided into groups according to the bleaching technique (G1 - only HP; G2 - HP associated with blue led; G3 - only blue led; G4 - HP associated with a violet led; and G5 - only violet led). The color analysis (ΔE, ΔL, and WID) and enamel surface microhardness were assessed before and after bleaching (immediately, 5, 14, and 30 days). The biological safety of the violet led irradiation was assessed by measuring the number of micronuclei formed in human cells in culture in response to irradiation. Data analysis included Kruskal-Wallis test, Friedman test, and Mann-Whitney test. RESULTS: In groups G4 and G5 there was the formation of precipitates on the enamel surface. At the time of 14 days, it was observed that the G2 group had lower values of microhardness than G5. ΔL and ΔE showed differences between groups in experimental times. Mean percentages of micronuclei occurrence were similar in the control group and the violet led group. CONCLUSION: The violet led irradiation can be applied for dental bleaching because this approach produces significant color changes preserving tooth enamel integrity and causes no genotoxic effects on vital cells.

Use of high-power lasers in pediatric dental surgeries: case reports.

The use of high-power diode laser technology follows the principles of minimally invasive dentistry. Laser technology is used frequently in pediatric dentistry, especially in surgical procedures, because this approach favors hemostasis, eliminates the use of sutures, improves healing, minimizes treatment time, reduces the sensation of pressure and vibration experienced by the patient, and creates more comfortable postoperative conditions. This article describes the use of high-power diode lasers to perform 3 minor oral surgical procedures--biopsy, lingual frenectomy, and operculectomy--in 2 children. In all 3 treatments, the operative time did not exceed 5 minutes, no sutures were used, and no postoperative complications were reported. Thus, high-power diode lasers can be considered an alternative approach to minor oral surgery that decreases chair time, reduces postoperative complications, and minimizes stress and anxiety in pediatric patients.

In-office bleaching protocols using violet LED: A split mouth case report.

A new LED wavelength, violet LED (VL) with a wavelength between 405 - 410 nm was recently introduced to be used for in-office dental bleaching. In comparison to the blue LED system (440 to 485 nm), the shorter wavelength has more energy carried in its photons and also corresponds to the absorption peak of the stained particles, which lead to whitening utilizing a physical process. Considering the need to suggest and develop new protocols with this new technology, this article reports 2 different dental bleaching protocols developed in a split-mouth model using VL. A 25-year-old male patient was submitted to in-office dental bleaching. On the teeth from the left side, the bleaching gel (35% H2O2) was renewed 3 times (every 8 mins), and on the right side, the gel was maintained without renewal during the bleaching session. The irradiation with Violet LED Light (405 nm ± 10 nm) was performed with the following protocol: 1 min of irradiation with 30 s light off until 8 min of total time. A total of 3 cycles were performed (total time of 24 min). Two bleaching sessions were performed with an interval of 7 days between sessions. Based on the results of this split-mouth case report, there was no visible difference in the final color outcome and sensitivity between both bleaching protocols tested.

How to use laser safely in times of COVID-19: Systematic review.

AIM: To conduct a systematic review of the literature on biosafety with the use of lasers. METHODS: The systematic review of literature was performed using MEDLINE (PubMed), Science Direct and Web of Science databases. The electronic search strategy included terms in the Medical Subject Heading (MeSH) related to biosafety in dentistry and laser, forms of contamination with aerosols, as well as their synonyms. The selected keywords were "aerosol virus transmission dentistry," "laser-generated air contaminants," "biosafety dentistry laser" combined with the terms AND/OR. RESULTS: A total of 1334 abstracts were reviewed, resulting in inclusion of 23 reviews. The dental surgeons are professionals with a high risk of contamination; high-power lasers form aerosols that need to be controlled and low-power lasers must be protected to minimize the risks of cross-infection. CONCLUSION: The biosafety of using lasers is important for professionals can be more oriented as to the correct use of this equipment. This study has the relevance of showing biosafety measures for the professional, staff and patients, as well as suggesting that more studies that are clinical should be conducted in this area.

Influence of biosafety materials of the laser output power.

Biosafety materials used in the correct handling of low power laser equipment may interfere on the power delivered at the target tissue and, possibly, on the effects on biological tissues. The aim of this study was to evaluate the interference of the use of polyvinyl chloride (PVC) and polyethylene (PEAD) protection materials on the output power of low power lasers. Two low power diode laser devices with different wavelengths (red and infrared) were used. For each wavelength, two protection materials and two evaluation times (before and after protection) were considered. The output power (mW) was measured with the tip positioned in close contact with the power meter receiver. Parametric statistical test, two-way ANOVA for repeated measures (protection material and time), was performed considering the level of significance of 5%. In respect to "time", all groups had the output power reduced after placing the protective material (p < 0.05). Comparing the protection materials, the PEAD showed a greater reduction in output power than the PVC for both red and infrared wavelengths. It was concluded that, among the biosafety materials tested, PVC is the most suitable for the protection of the tip of the low power lasers.

Association of antimicrobial photodynamic therapy and photobiomodulation for herpes simplex labialis resolution: Case series.

Antimicrobial Photodynamic Therapy (aPDT) with photobiomodulation therapy (PBT) can be used in herpes simplex and may have a role in improving modulation of inflammatory process, pain relief and acceleration of tissue repair. This article reports through a case series, a proposal for an efficient resolution in clinical manifestations of herpes simplex labialis using aPDT associated with PBT.

Does pre-irradiation time influence the efficacy of antimicrobial photodynamic therapy?

Antimicrobial photodynamic therapy (aPDT) has emerged as a promising antimicrobial treatment to control microorganisms including those involved in oral diseases, especially dental caries. Hence, the aim of this study was to evaluate the influence of aPDT - pre-irradiation time (PIT), at different periods, on antimicrobial rate of Streptococcus mutans (S. mutans). A standard suspension of S. mutans UA159 was prepared and submitted at sensitization of 0.005 % methylene blue (MB) for 0, 1, 3 and 5 min (G1 - G4 groups, respectively) and irradiated with a red laser (660 nm; 321 J/cm2; 9 J; 90 s) afterward. A control group using PBS instead of MB was performed as well (G5). The number of colony-forming units (CFU)/mL was recorded, transformed into log10 and analyzed by ANOVA and Tukey's test at a cutoff value at 0.05. Overall, the aPDT groups tested achieved a bacterial reduction > 1-log10 when compared to G5 (p < 0.05) with no statistical difference among the different PIT tested. The need of PIT before aPDT application deserves attention, since its time reduction implies on shorter clinical approaches without compromising the photodynamic antibacterial efficacy in the in vitro parameters employed.

Correspondence between try-in pastes and resin cements, and color stability of bonded lithium disilicate disks.

This study investigates the color correspondence of resin cements and try-in pastes, and the color stability of bonded lithium disilicate ceramic disks. Resin composite disks were fabricated (n = 36) to serve as the background for lithium disilicate disks prepared in two thicknesses (0.5 and 1.0 mm, n = 18 each). Two brands were used for try-in and cement procedures: Variolink Veneer and AllCem Veneer. For baseline, water was applied between the ceramic disks and their respective backgrounds to achieve the control group. This set was subjected to color measurement using an intraoral measurement device (T0). The try-in was inserted between background and ceramic, and this set was subjected to color measurement (T1). After adhesive procedures, the ceramic disk was placed under cement, and color measurement was performed with uncured cement (T2) and 24 h after light-curing (T3). Each set was immersed in distilled water and thermal-cycled, with color measurement being performed after 10,000 (T4) and 20,000 (T5) cycles. Color differences were calculated by CIELab (rEab) and CIEDE2000 (rE00). Data were analyzed by two-way ANOVA for repeated measurements and Tukey's test (α=5%). There was color correspondence of try-in and resin cement for the Variolink system, regardless of the ceramic thickness (p > 0.05). For the AllCem system, the thickness significantly influenced the color measurement (p < 0.001). The Variolink system also demonstrated color stability after 20,000 thermal cycles with rEab < 3.46 and rE00 < 2.25. It was concluded that the color correspondence between a try-in and its respective cement may vary according to resin cement composition.

Effect of Terminalia catappa Linn. on Biofilms of Candida albicans and Candida glabrata and on Changes in Color and Roughness of Acrylic Resin.

This study aimed to investigate the effect of the n-butanol fraction of Terminalia catappa Linn., (FBuTC) on biofilm of Candida albicans and Candida glabrata, as well as changes in color and roughness of polymethyl methacrylate resin (PMMA). The susceptibility of C. albicans and C. glabrata to FBuTC was evaluated by means of the Minimum Inhibitory and Minimum Fungicidal Concentration (MIC and MFC). PMMA acrylic resin discs (N= 108) were fabricated. For the susceptibility tests, biofilms of C. albicans and C. glabrata were developed on discs for 48 h and immersed in phosphate-saline buffer solution (PBS), 1% sodium hypochlorite (SH 1%), or FBuTC at MIC, 5xMIC, or 10xMIC. For the color and roughness change tests, the discs were immersed in distilled water, SH 1%, or FBuTC in the concentrations of 0.25 mg/mL, 2.5 mg/mL, or 25.0 mg/mL. After 28 days of incubation, color change was evaluated by spectrophotometry and roughness, by using a profilometer. The biofilms were investigated by one-way ANOVA and, the color and roughness changes (two-way ANOVA and the Tukey test; α=0.05). For both MIC and MFC the value of 0.25 mg/mL of FBuTC was observed for the planktonic cells of C. albicans and C. glabrata. Exposure to FBuTC at 10xMIC had a significant effect on the biofilm of C. albicans, showing a reduction in cell counts when compared with PBS, (p=0.001). For the biofilm of C. glabrata, the MIC was sufficient for significantly reducing the cell count (p<0.001). No important changes in color and roughness of the acrylic resin were observed, even after 28 days, irrespective of the concentration of FBuTC used (p >0.05). It could be concluded that the immersion of acrylic resin for dental prosthesis in FBuTC was effective in reducing the biofilms of C. albicans and C. glabrata without evidence of change in roughness and color of this substrate.

High Power Laser and Photobiomodulation in Oral Surgery: Case Report.

Introduction: The labial frenum is a fold of mucous membrane that attaches the lip and the cheek to the alveolar mucosa, the gingiva, and the underlying periosteum. In some cases, its presence can cause a midline diastema, periodontal diseases related to food impaction, or retention of biofilm, among others. In such cases, lip frenectomy is indicated as treatment, which can be performed with a scalpel (conventional method), an electric scalpel, or a surgical laser. Objective: To show a clinical case performed at Laser Extension Project in Dentistry, Federal University of Maranhão grounded in a literature review. Case Presentation: A laser frenectomy was performed on a female patient, aged 20, who had a diastema between the upper central incisors and an indication for frenum removal. The high-power diode laser is excellent for procedures in soft tissue because its wavelength is well absorbed by hemoglobin and other pigments; its use also allows a reduction in the amount of anesthetic and medicines used. The parameters used were 2 W, in a continuous mode, 808 nm infrared emission; with delivery of the beam through optical fiber 300 µM; energy of 120 J; 20 pps. Conclusion: the high power diode laser allowed a satisfactory result, the procedure was safe, the technique was a simple one and of reduced clinical time, as mentioned in the literature. It is worth noting that the technique is dependent on the skill of the professional performing it.

Correspondence between try-in pastes and resin cements, and color stability of bonded lithium disilicate disks

Abstract: This study investigates the color correspondence of resin cements and try-in pastes, and the color stability of bonded lithium disilicate ceramic disks. Resin composite disks were fabricated (n = 36) to serve as the background for lithium disilicate disks prepared in two thicknesses (0.5 and 1.0 mm, n = 18 each). Two brands were used for try-in and cement procedures: Variolink Veneer and AllCem Veneer. For baseline, water was applied between the ceramic disks and their respective backgrounds to achieve the control group. This set was subjected to color measurement using an intraoral measurement device (T0). The try-in was inserted between background and ceramic, and this set was subjected to color measurement (T1). After adhesive procedures, the ceramic disk was placed under cement, and color measurement was performed with uncured cement (T2) and 24 h after light-curing (T3). Each set was immersed in distilled water and thermal-cycled, with color measurement being performed after 10,000 (T4) and 20,000 (T5) cycles. Color differences were calculated by CIELab (rEab) and CIEDE2000 (rE00). Data were analyzed by two-way ANOVA for repeated measurements and Tukey's test (α=5%). There was color correspondence of try-in and resin cement for the Variolink system, regardless of the ceramic thickness (p > 0.05). For the AllCem system, the thickness significantly influenced the color measurement (p < 0.001). The Variolink system also demonstrated color stability after 20,000 thermal cycles with rEab < 3.46 and rE00 < 2.25. It was concluded that the color correspondence between a try-in and its respective cement may vary according to resin cement composition.

Is It Necessary to Prepare the Enamel before Dental Bleaching?

The aim of this in vitro study was to assess the influence of distinct surface treatments on the microhardness and color of enamel that will be bleached. Surface treatments are tested, accordingly: G1, no treatment; G2, 2% sodium fluoride; G3, casein phosphopeptide paste; G4, 2% fluoride+Nd:YAG laser. Forty blocks from bovine teeth composed the sample that were tested in Knoop microhardness (n = 10) and in color change (n = 10). After 24 h, bleaching with 35% hydrogen peroxide was performed for 45 min. Microhardness and color changes (using parameters ΔE, ΔL, Δa, and Δb) were assessed before and after bleaching. The data were analyzed by two-way ANOVA and Tukey's test (p < 0.05). Despite all surface treatments, a reduction of enamel microhardness occurred immediately after bleaching in all groups, being greater in G1. Enamel color changed in all groups. Immediately after bleaching, there was a decrease on enamel microhardness. However, after 7 days, some of those specimens previously treated before bleaching significantly recovered their initial microhardness without influencing the esthetic results of bleaching.

Does the hybrid light source (LED/laser) influence temperature variation on the enamel surface during 35% hydrogen peroxide bleaching? A randomized clinical trial.

OBJECTIVE: The present study investigated how a hybrid light source (LED/laser) influences temperature variation on the enamel surfaces during 35% hydrogen peroxide (HP) bleaching. Effects on the whitening effectiveness and tooth sensitivity were analyzed. METHOD AND MATERIALS: Twenty-two volunteers were randomly assigned to two different treatments in a split-mouth experimental model: group 1 (control), 35% HP; group 2 (experimental), 35% HP + LED/laser. Color evaluation was performed before treatment, and 7 and 14 days after completion of bleaching, using a color shade scale. Tooth sensitivity was assessed using a visual analog scale (VAS; before, immediately, and 24 hours after bleaching). During the bleaching treatment, thermocouple channels positioned on the tooth surfaces recorded the temperature. Data on color and temperature changes were subjected to statistical analysis (α = 5%). Tooth sensitivity data were evaluated descriptively. RESULTS: Groups 1 and 2 showed mean temperatures (± standard deviation) of 30.7 ± 1.2 °C and 34.1 ± 1.3 °C, respectively. It was found that there were statistically significant differences between the groups, with group 2 showing higher mean variation (P < .0001). The highest temperature variation occurred for group 2, with an increase of 5.3 °C at the enamel surface. The color change results showed no differences in bleaching between the two treatment groups (P = .177). The variation of the average temperature during the treatments was not statistically associated with color variation (P = .079). Immediately after bleaching, it was found that 36.4% of the subjects in group 2 had mild to moderate sensitivity. In group 1, 45.5% showed moderate sensitivity. In both groups, the sensitivity ceased within 24 hours. CONCLUSION: Hybrid light source (LED/ laser) influences temperature variation on the enamel surface during 35% HP bleaching and is not related to greater tooth sensitivity.