Nd:YAG/Er:YAG dual laser compared with topical steroid to treat vulvar lichen sclerosus: A randomised controlled trial.

OBJECTIVE: To evaluate the efficacy and safety of a novel non-ablative Nd:YAG/Er:YAG dual laser treatment for vulvar lichen sclerosus (LS) in comparison with the recommended first-line therapy with topical steroid. DESIGN: A randomised investigator-initiated active-controlled trial. SETTING: Single tertiary referral centre. POPULATION: Women with vulvar LS. METHODS: Randomisation (2:1) to Nd:YAG/Er:YAG laser therapy or topical clobetasol proprionate therapy. Four laser treatments at 0, 1, 2 and 4 months or decreasing doses of steroid for 6 months. MAIN OUTCOME MEASURES: The primary outcome was the change in objective validated clinical LS score in the laser arm between baseline and 6 months. Secondary outcomes were laser tolerability/safety, symptom scores and patient satisfaction. RESULTS: Sixty-six women were included, 44 in the laser group and 22 in the steroid group. The total LS score decreased by -2.34 ± 1.20 (95% CI -2.71 to -1.98) in women treated with laser compared with a decrease of -0.95 ± 0.90 (95% CI -1.35 to -0.56) in those receiving steroid applications (p < 0.001). Laser treatment was safe and well tolerated. Subjective severity scores (on visual analogue scale) and vulvovaginal symptoms questionnaire scores improved similarly for the laser and steroid arms without significant differences between the two treatments. Patient satisfaction was higher in the laser arm than in the steroid arm (p = 0.035). CONCLUSIONS: Non-ablative dual Nd:YAG/Er:YAG laser therapy was safe and significantly improved clinical outcome and subjective symptoms at the 6-month follow up. This suggests that laser may be a promising alternative to corticosteroid therapy. However, the authors caution regular follow ups because of the premalignant nature of the disease.

Phase-locked µPIV analysis of flow dynamics in a simulated root canal with different laser-activated irrigations.

PURPOSE: To measure the dynamic characteristics of the flow field in a complex root canal model activated by two laser-activated irrigation (LAI) modalities at different activation energy outputs: photon-induced photoacoustic streaming (PIPS) and microshort pulse (MSP). METHODS: A phase-locked micro-scale Particle Image Velocimetry (µPIV) system was employed to characterise the temporal variations of LAI-induced velocity fields in the root canal following a single laser pulse. The wall shear stress (WSS) in the lateral root canal was subsequently estimated from the phase-averaged velocity fields. RESULTS: Both PIPS and MSP were able to generate the 'breath mode' of the irrigant current under all tested conditions. The transient irrigation flush in the root canal peaked at speeds close to 6 m/s. However, this intense flushing effect persisted for only about 2000 µs (or 3% of a single laser-pulse activation cycle). For MSP, the maximum WSS magnitude was approximately 3.08 Pa at an activation energy of E = 20 mJ/pulse, rising to 9.01 Pa at E = 50 mJ/pulse. In comparison, PIPS elevated the WSS to 10.63 Pa at E = 20 mJ/pulse. CONCLUSION: Elevating the activation energy can boost the peak flushing velocity and the maximum WSS, thereby enhancing irrigation efficiency. Given the same activation energy, PIPS outperforms MSP. Additionally, increasing the activation frequency may be an effective strategy to improve irrigation performance further.

Root surface roughness evaluation following application of different periodontal instruments and Er:YAG laser: A profilometry and SEM study.

AIM: The aim of the present study was to evaluate the efficacy of 30°-angled Er:YAG laser tip and different periodontal instruments on root surface roughness and morphology in vitro. METHODS: Eighteen bovine teeth root without carious lesion were decoronated from the cementoenamel junction and seperated longitidunally. A total of 36 obtained blocks were mounted in resin blocks and polished with silicon carbide papers under water irrigation. These blocks were randomly assigned into 3 treatment groups. In Group 1, 30°-angled Er:YAG laser (2.94 µm) tip was applied onto the blocks with a 20 Hz, 120 mJ energy output under water irrigation for 20 s. In Groups 2 and 3, the same treatment was applied to the blocks with new generation ultrasonic tip and conventional curette apico-coronally for 20 s with a sweeping motion. Surface roughness and morphology were evaluated before and after instrumentation with a profilometer and SEM, respectively. RESULTS: After instrumentation, profilometric analysis revealed significantly higher roughness values compared to baseline in all treatment groups(p < 0.05). Laser group revealed the roughest surface morphology followed by conventional curette and new generation ultrasonic tip treatment groups (p < 0.05). In SEM analysis, irregular surfaces and crater defects were seen more frequently in the laser group. CONCLUSION: Results of the study showed that the use of new generation ultrasonic tip was associated with smoother surface morphology compared to 30°-angled Er-YAG laser tip and conventional curette. Further in vitro and in vivo studies with an increased sample size are necessary to support the present study findings.

Evaluation and comparison of Q-switched Nd: YAG laser 1064 nm and Er: YAG laser 2940 nm in the treatment of macular amyloidosis.

Macular amyloidosis (MA) is one of the most common types of primary localized cutaneous amyloidosis (PLCA), distributed predominantly over the trunk and extremities. Due to the vast therapeutic options, this study aims to compare the effectiveness of Q-switched Nd: YAG laser 1064 nm and Er: YAG laser 2940 nm in treating MA. This clinical trial was performed in 2020-2021 on 33 women with MA. In each patient, the lesion was randomly divided into two areas, A and B. Area A underwent four treatment sessions with 4-week intervals of Q-switched Nd: YAG laser 1064 nm. Area B underwent four treatment sessions with an Er: YAG laser 2940 nm at 4-week intervals. Degree of basal pigmentation and degree of pigmentation after treatment, pruritus intensity, before and after the treatment, and patient and physicians' satisfaction were measured and compared. The pruritus in patients improved significantly after the study (P < 0.001), but no significant differences could be observed between the two groups regarding the improvements (P > 0.05). We also found no significant differences between the two groups of patients regarding patient and physicians' satisfaction rates (P > 0.05). The use of both Q-switched Nd: YAG laser and Er: YAG laser resulted in improvements in terms of pruritus, patient and physicians' satisfaction, and total improvement in pigmentation of the lesions.

Er:YAG Laser Alleviates Inflammaging in Diabetes-Associated Periodontitis via Activation CTBP1-AS2/miR-155/SIRT1 Axis.

Periodontitis is a significant health concern for individuals with diabetes mellitus (DM), characterized by inflammation and periodontium loss. Hyperglycaemia in DM exacerbates susceptibility to periodontitis by inducing inflammaging in the host immune system. The use of erbium-doped yttrium-aluminum-garnet laser (ErL) in periodontitis treatment has gained attention, but its impact on diabetic-associated periodontitis (DP) and underlying mechanisms remain unclear. In this study, we simulated DP by exposing human periodontal ligament fibroblasts (PDLFs) to advanced glycation end products (AGEs) and lipopolysaccharides from P. gingivalis (Pg-LPS). Subsequently, we evaluated the impact of ErL on the cells' wound healing and assessed their inflammaging markers. ErL treatment promoted wound healing and suppressed inflammaging activities, including cell senescence, IL-6 secretion, and p65 phosphorylation. Moreover, the laser-targeted cells were observed to have upregulated expression of CTBP1-AS2, which, when overexpressed, enhanced wound healing ability and repressed inflammaging. Moreover, bioinformatic analysis revealed that CTBP1-AS2 acted as a sponge for miR155 and upregulated SIRT1. In conclusion, ErL demonstrated the ability to improve wound healing and mitigate inflammaging in diabetic periodontal tissue through the CTBP1-AS2/miR-155/SIRT1 axis. Targeting this axis could represent a promising therapeutic approach for preventing periodontitis in individuals with DM.

Effect of chitosan and CMCS on dentin after Er:YAG laser irradiation: shear bond strength and surface morphology analysis.

OBJECTIVES: The aim of the present study was to evaluate the effect of chitosan and carboxymethyl chitosan (CMCS) on dentin surface morphology and bonding strength after irradiation of Er:YAG laser. METHODS: Eighty-four laser-irradiated dentin samples were randomly distributed into three groups (n = 28/group) according to different surface conditioning process: deionized water for 60s; 1wt% chitosan for 60s; or 1wt% CMCS for 60s. Two specimens from each group were subjected to TEM analysis to confirm the presence of extrafibrillar demineralization on dentin fibrils. Two specimens from each group were subjected to morphological analysis by SEM. Seventy-two specimens (n = 24/group) were prepared, with a composite resin cone adhered to the dentin surface, and were then randomly assigned to one of two aging processes: storage in deionized water for 24 h or a thermocycling stimulation. The shear bond strength of laser-irradiated dentin to the resin composite was determined by a universal testing machine. Data acquired in the shear bond strength test was analyzed by one-way ANOVA with the Tukey honestly significant difference post hoc test and Independent Samples t-test (α = 0.05). RESULTS: CMCS group presented demineralized zone and a relatively smooth dentin surface morphology. CMCS group had significantly higher SBS value (6.08 ± 2.12) without aging (p < 0.05). After thermal cycling, both chitosan (5.26 ± 2.30) and CMCS group (5.82 ± 1.90) presented higher bonding strength compared to control group (3.19 ± 1.32) (p < 0.05). Chitosan and CMCS group preserved the bonding strength after aging process (p > 0.05). CONCLUSIONS: CMCS has the potential to be applied in conjunction with Er:YAG laser in cavity preparation and resin restoration.

A Preliminary Study in Er:YAG Laser Debonding of Lithium Disilicate Crowns: Laser Power Setting vs Crown Thickness.

Background: Er:YAG laser is widely used in debonding of all-ceramic veneers nowadays. However, the data about laser parameters in all-ceramic crown removal is limited. The aim of this preliminary study was to determine the most appropriate laser parameters at safe heat transmission values ​​for lithium disilicate crowns in different thicknesses. Methods: Twenty-seven intact premolars were prepared to fabricate lithium disilicate CAD/CAM full-coverage crowns in three different thicknesses: 1, 1.5 mm, and mixed thickness (n=9). Each thickness group was divided into 3 subgroups and subjected to Er:YAG laser at different wattages (5, 5.6 and 5.9 W) to determine the appropriate wattage for each thickness. The removal time and temperature rise values were recorded. The Kruskal-Wallis test was performed to evaluate any significant differences in removal time, Mann-Whitney U test with Bonferroni correction for multiple comparisons, and the Pearson chi-square test for temperature rise over the critical value (p<0.05). Results: Laser irradiation at 5 W was safe and efficient for 1 mm thickness, while not efficient for others. Laser application at 5.9 W was efficient for all thicknesses, but, not safe for 1 mm thickness. The statistically significant difference in removal time was only between 5 W and 5.9 W groups (p=0.035). Pearson's chi-square test revealed that the temperature rise after 5.9 W laser application was significantly different from 5 W in 1 mm thickness group (p=0.043). Conclusion: Er:YAG laser lithium disilicate crown removal is an effective and safe method using laser settings appropriate for crown thickness.

SUI in postmenopausal women: advantages of an intraurethral + intravaginal Er:YAG laser.

OBJECTIVE: This study aimed to compare the efficacy of concomitant application of an intraurethral (IU) + intravaginal (IV) non-ablative Erbium (Er):YAG laser with IV application in improving the symptoms of stress urinary incontinence (SUI) in women. METHODS: This observational retrospective cohort study included 122 patients with SUI, 60 women in the IU + IV laser arm and 62 in the IV laser arm. The primary outcome was the International Consultation on Incontinence Questionnaire - Urinary Incontinence Short Form score at entry and at 3, 6 and 12 months from baseline. RESULTS: Demographic characteristics were comparable in both arms. Significant improvement in SUI symptoms was seen 3 months after the intervention and was sustained until the end of month 12 in both arms. The women who had severe SUI symptoms initially showed greater improvement. A higher number of women who initially had mild to moderate SUI symptoms were dry after treatment. Patients treated with IU + IV Er:YAG laser showed significant improvement in SUI symptoms compared to IV laser only, especially at postmenopausal state (p = 0.003). CONCLUSIONS: The Er:YAG laser appears to be an efficient treatment method for SUI. Concomitant application of an IU + IV Er:YAG laser is more effective in relieving SUI symptoms at postmenopausal state.

Evaluation of the adjunctive use of Er:YAG laser or erythritol powder air-polishing in the treatment of peri-implant mucositis: A randomized clinical trial.

AIM: To assess the efficacy of Er:YAG laser (ERL) and erythritol powder air-polishing (AP) in addition to the submarginal instrumentation in the non-surgical treatment of peri-implant mucositis (PM). MATERIALS AND METHODS: Patients with at least one implant diagnosed with PM were included in the present 6-month randomized clinical trial (RCT). Implants were randomly assigned to one of the three treatment groups after submarginal instrumentation: AP (test 1 group), ERL (test 2 group) or no adjunctive methods (control group). The primary and secondary outcomes were, respectively, bleeding on probing (BoP) reduction and, complete disease resolution (total absence of BoP) and probing pocket depth (PPD) changes. The patient and the implant were considered the statistical unit. A multivariate logistic regression analysis was performed. RESULTS: A total of 75 patients were enrolled in the study. At each time point, significant BoP and PPD reductions were observed within each group. Intergroup analysis did not show statistically significant differences. Complete disease resolution ranged between 29% and 31%. The logistic regression showed that supramucosal restoration margin, PPD < 4 mm and vestibular keratinized mucosa (KM) significantly influenced the probability to obtain treatment success. CONCLUSION: The adjunctive use of AP and ERL in PM non-surgical therapy does not seem to provide any significant or clinically relevant benefit in terms of BoP and PPD reductions and complete disease resolution, over the use of submarginal instrumentation alone. Baseline PPD < 4 mm, presence of buccal KM and supramucosal restoration margin may play a role in the complete resolution of PM.

Comparison of Er:YAG and CO2 laser therapy for women with stress urinary incontinence.

OBJECTIVE: To compare the effectiveness of Er:YAG and CO2 laser therapies for treating female stress urinary incontinence (SUI). METHODS: This retrospective study included 139 women who were divided into four groups: group 1 received two therapy sessions with the Er:YAG laser, group 2 received two therapy sessions with the CO2 laser, group 3 received one therapy session with the Er:YAG laser, and group 4 received one therapy session with the CO2 laser. Patients completed three questionnaires to assess SUI symptom severity at baseline, 1 month, and 3 months after laser therapy. RESULTS: Urinary incontinence symptoms significantly improved in groups 1 and 2 at both the 1- and 3-month follow-up evaluations compared to the baseline (p < 0.001). Symptoms improved after one therapy session in groups 3 and 4 at the 3-month follow-up (p < 0.001). The Er:YAG laser was more effective than the CO2 laser in improving SUI symptoms (Urogenital Distress Inventory 6 and Incontinence Impact Questionnaire 7) 3 months after treatment, regardless of the number of sessions. Both Er:YAG and CO2 laser therapies were found to be effective in reducing symptoms associated with an overactive bladder, as demonstrated by improvements in overactive bladder symptom scores. Two sessions of laser therapy were more effective than one. CONCLUSION: Vaginal laser therapy could be an effective alternative treatment for mild to moderate SUI. The Er:YAG laser was more effective than CO2 laser therapy, with results lasting for at least 3 months. However, further large-scale, randomized, controlled trials are needed to confirm our findings.

Multimodal feedback systems for smart laser osteotomy: Depth control and tissue differentiation.

OBJECTIVES: The study aimed to improve the safety and accuracy of laser osteotomy (bone surgery) by integrating optical feedback systems with an Er:YAG laser. Optical feedback consists of a real-time visual feedback system that monitors and controls the depth of laser-induced cuts and a tissue sensor differentiating tissue types based on their chemical composition. The developed multimodal feedback systems demonstrated the potential to enhance the safety and accuracy of laser surgery. MATERIALS AND METHODS: The proposed method utilizes a laser-induced breakdown spectroscopy (LIBS) system and long-range Bessel-like beam optical coherence tomography (OCT) for tissue-specific laser surgery. The LIBS system detects tissue types by analyzing the plasma generated on the tissue by a nanosecond Nd:YAG laser, while OCT provides real-time monitoring and control of the laser-induced cut depth. The OCT system operates at a wavelength of 1288 ± 30 nm and has an A-scan rate of 104.17 kHz, enabling accurate depth control. Optical shutters are used to facilitate the integration of these multimodal feedback systems. RESULTS: The proposed system was tested on five specimens of pig femur bone to evaluate its functionality. Tissue differentiation and visual depth feedback were used to achieve high precision both on the surface and in-depth. The results showed successful real-time tissue differentiation and visualization without any visible thermal damage or carbonization. The accuracy of the tissue differentiation was evaluated, with a mean absolute error of 330.4 µm and a standard deviation of ±248.9 µm, indicating that bone ablation was typically stopped before reaching the bone marrow. The depth control of the laser cut had a mean accuracy of 65.9 µm with a standard deviation of ±45 µm, demonstrating the system's ability to achieve the pre-planned cutting depth. CONCLUSION: The integrated approach of combining an ablative laser, visual feedback (OCT), and tissue sensor (LIBS) has significant potential for enhancing minimally invasive surgery and warrants further investigation and development.

Histological evaluation of mouse tongue incisions after Er:YAG laser surgery with different pulse energies versus after conventional scalpel surgery.

PURPOSE: To identify the surgical instrument that allows for optimal healing of tongue incisions. METHODS: An Er:YAG laser was compared with different pulse energies to a conventional scalpel for the incision of mouse tongue tissues. Mice were sacrificed through cervical dislocation at 24, 48, and 72 h postoperatively, followed by extraction of their tongues for incision experiments. The healing of the incisions and expression of inflammation- and pain-related factors in the tongues were compared between the surgical procedure groups. RESULTS: In laser-treated mice, tongue incisions healed the fastest when the laser output energy was 60 MJ per pulse. Macrophage chemotaxis toward the incisional area was triggered on the first postoperative day for the 60-MJ group, while the time for macrophage chemotaxis to the surgical area was later in the 80-MJ group. Tumor necrosis factor-alpha expression increased and then decreased in the 80-MJ group; however, it gradually decreased in the 60-MJ and conventional scalpel groups. Prostaglandin E2 expression increased and then decreased in the 80-MJ and conventional scalpel groups but gradually decreased in the 60-MJ group. The expression of transforming growth factor beta 1 gradually decreased in the 60-MJ and 80-MJ groups but gradually increased in the conventional scalpel group. CONCLUSION: Compared with surgical procedures using conventional scalpels, those using an Er:YAG laser with appropriate pulse energies can inhibit inflammation in the incisional area and promote incision healing. The use of an Er:YAG laser with appropriate pulse energies can alleviate intraoperative and postoperative pain in the incisional area.

Er:YAG laser therapy in combination with GLUMA desensitizer reduces dentin hypersensitivity in children with molar-incisor hypomineralization: a randomized clinical trial.

This study aimed to investigate the effectiveness of erbium-doped yttrium garnet (Er:YAG) laser and GLUMA desensitizer for dentin hypersensitivity in teeth affected by Molar-Incisor Hypomineralization (MIH). One hundred twenty children were randomly allocated to four groups: the control (Co) group, the desensitizer (De) group, the laser (La) group, and the laser + desensitizer (La + De) group. Outcome measures included Visual Analogue Scale (VAS) and 14-item Oral Health Impact Profile (OHIP-14) evaluation. For mean VAS scores, a significant reduction was found over time in all groups. Co and De groups, Co and La groups, Co and La + De groups, De and La + De groups, and La and La + De groups differed significantly (p < 0.05). For mean scores in all dimensions of OHIP-14 after treatment 6 months, the La + De group was significantly lower (p < 0.001). The La + De groups and the La groups as well as the La + De groups and the De groups differed significantly in total OHIP, functional limitation, physical disability, and psychological disability (p < 0.05). Physical pain between the La + De groups and the La groups and handicap between the La + De groups and De groups differed significantly (p < 0.05). The mean values of each dimension differed significantly between the group Co and the La + De group (p < 0.0001). Combination therapy of Er:YAG laser and GLUMA desensitizer had greater desensitizing effects and oral health-related quality improvement of life, which might be an effective alternative treatment in dentin hypersensitivity in MIH children.

Shear bond strengths of bur or Er:YAG laser prepared dentine to composite resin with or without low-level laser conditioning: an in vitro study.

This study aims to compare the different modes of cavity preparation while evaluating the effect of low-level laser therapy (LLLT) on dentine before bonding in terms of shear bond strength between composite resin and dentine. Fifty human molar teeth were mounted on acrylic blocks and dentine specimen were prepared after which they were randomized into four equal groups. Cavity preparation mode differed in respective groups. After etching, bonding; composite resin was placed and polymerized on the prepared dentine surfaces. The specimens were kept in an environment simulating oral cavity and then shear tested in a universal testing machine. The failure surfaces of the specimen teeth were subjected to SEM micrographic evaluation. The cavity prepared with diamond abrasive points had a higher shearing load at failure that was statistically significantly different from the ones prepared with laser. That with diamond abrasive points followed by LLLT of the cavity surface with Nd:YAG laser had a higher bond strength than the ones prepared with just Er:YAG laser and there was no statistically significant difference between these and the ones prepared with diamond abrasive points alone. SEM analysis of the failure mode in bur-cut dentine showed the presence of a hybrid layer at the interface. Surface conditioning of the same with Nd:YAG laser before etching suggested a recrystallisation of dentine due to the heat produced. Cavity preparation with Er:YAG laser leads to reduced shear bond strength to adhesive restorative materials when compared with that using burs and high-speed handpiece.

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.

Repair bond strength of different CAD-CAM ceramics after various surface treatments combined with laser irradiation.

The aim of this study was to evaluate the effect of different surface treatments combined with laser irradiation on the shear bond strength of different CAD-CAM ceramics to composite resin. A total of hundred forty-seven ceramic specimens with thicknesses of 2.5 mm were prepared from three different CAD-CAM ceramics (an yttrium oxide partially stabilized tetragonal zirconia polycrystal (Y-TZP); a zirconia-reinforced lithium silicate glass ceramic (ZLS); and a lithium disilicate-strengthened lithium aluminosilicate glass ceramic (LD-LAS)) and subjected to seven groups of treatment (n = 7): (1) control (no treatment), (2) Er:YAG laser irradiation, (3) Nd:YAG laser irradiation, (4) etching with hydrofluoric acid (HFA), (5) Er:YAG + HFA, (6) Nd:YAG + HFA, and (7) sandblasting. After surface treatment procedures, a ceramic primer (Clearfil Ceramic Primer Plus, Kuraray, Japan) was applied to the ceramics. Bonding agent (Single Bond Universal Adhesive, 3 M ESPE, USA) was then applied, and the composite resin (Estelite Sigma Quick, Kuraray, Japan) was layered on the ceramic surfaces. The shear bond strength test was performed using a universal testing machine at a load of 0.5 mm/min. Data were analyzed by 2-way analysis of variance (ANOVA), and the Bonferroni correction was used for pairwise comparisons (α = 0.05). Compared to the bond strength of the control group, irradiation by Er:YAG and Nd:YAG lasers alone improved the bond strength of the composite resin to the Y-TZP (P < 0.001) but did not change the bond strength of composite resin to the ZLS and LD-LAS (P > 0.05). Compared to the bond strength of the control group, etching with HFA alone increased the bond strength of the composite resin to the ZLS and LD-LAS (P < 0.001) but did not affect the bond strength of the composite resin to the Y-TZP (P > 0.05). The highest bond strength of ZLS was obtained using HFA + Er:YAG, and the highest bond strength for LD-LAS was obtained using HFA + Nd:YAG. It was concluded that Er:YAG and Nd:YAG laser treatments presented the highest repair bond strength between the composite resin and Y-TZP ceramics. Er:YAG and Nd:YAG laser treatments in conjuction with HFA presented the highest repair bond strength between the composite resin and the glassy ceramics, ZLS, and LD + LAS.

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.

A study of the objective benefits and safety of Er-YAG laser in the treatment of genitourinary syndrome of menopause.

The aim of this study is to evaluate changes in vaginal pH and epithelium maturation after erbium-doped yttrium aluminum garnet (Er-YAG) laser treatment, and to assess its safety and efficacy on the symptoms of genitourinary syndrome of menopause (GSM). This was a retrospective study conducted between November 2019 and April 2022 and included 32 women diagnosed with GSM who had not benefitted from lubrication treatment and could not or would not use estrogen. Patients received three sessions of Er- YAG laser. All patient data before and after treatment were obtained from computer records. Vaginal maturation index (VMI), maturation value (MV) and vaginal pH values of the patients before and after laser treatment were compared. We also evaluated post-procedural complications and symptoms. Mean age was 59.72 ± 5.66 years. After laser therapy, there was a significant decrease in vaginal pH (p < 0.001) and the proportion of parabasal cells in VMI (p < 0.001), while there was a significant increase in MV (p < 0.001) and the proportion of superficial cells in VMI (p < 0.001). In 84.4% of the patients, GSM-related symptoms regressed completely or decreased to a tolerable level. Patients in which symptoms disappeared completely had significantly lower mean age (p = 0.002) and duration of menopause (p = 0.009). The laser procedure resulted in complications including mucosal injury in 5 (15.6%) patients (all recovered spontaneously) and vaginal burning sensation in 2 (6.3%) patients. Vaginal Er-YAG laser treatment may be a safe and effective alternative treatment method in a population of women with GSM who do not want to or cannot use estrogen therapy.

A systematic review of the comparison between needling (RF-needling, meso-needling, and micro-needling) and ablative fractional lasers (CO2, erbium YAG) in the treatment of atrophic and hypertrophic scars.

The aim of this study is to compare needling (RF-needling, meso-needling, micro-needling) and ablative fractional lasers (CO2, erbium-YAG) in the treatment of atrophic and hypertrophic scars in a systematic review. The database was searched, and 10 articles were selected that were relevant in terms of content, topic, and purpose and met the inclusion criteria. Of all the articles reviewed in this study, there were 2 randomized split-face trials (20%), 1 controlled nonrandomized trial (10%), 1 controlled randomized phase III clinical trial (10%), 1 prospective trial (10%), 1 prospective nonrandomized open-label trial (10%), and 1 randomized comparative trial (10%), with the type of study not reported in 3 articles. We used Endnote X8 to review the articles and extract data. After review, the studies were analyzed and categorized. No statistically significant difference was found between the two methods, laser and micro-needling, in the treatment of atrophic and hypertrophic scars in 60% of the articles studied, and both showed significant improvement (70% or more improvement to complete response). Significant improvement was noted in 20% of the studies reviewed for the laser and micro-needling treatment methods. The results of this study show that needling and ablative fractional lasers are tolerable and safe procedures with no significant difference in the treatment of skin scars in sixty percent of the studies.

Effect of Er:YAG Pulsed Laser-Deposited Hydroxyapatite Film on Titanium Implants on M2 Macrophage Polarization In Vitro and Osteogenesis In Vivo.

In a previous study, we successfully coated hydroxyapatite (HAp) onto titanium (Ti) plates using the erbium-doped yttrium aluminum garnet pulsed-laser deposition (Er:YAG-PLD) method. In this study, we performed further experiments to validate the in vitro osteogenic properties, macrophage polarization, and in vivo osseointegration activity of HAp-coated Ti (HAp-Ti) plates and screws. Briefly, we coated a HAp film onto the surfaces of Ti plates and screws via Er:YAG-PLD. The surface morphological, elemental, and crystallographic analyses confirmed the successful surface coating. The macrophage polarization and osteogenic induction were evaluated in macrophages and rat bone marrow mesenchymal stem cells, and the in vivo osteogenic properties were studied. The results showed that needle-shaped nano-HAp promoted the early expression of osteogenic and immunogenic genes in the macrophages and induced excellent M2 polarization properties. The calcium deposition and osteocalcin production were significantly higher in the HAp-Ti than in the uncoated Ti. The implantation into rat femurs revealed that the HAp-coated materials had superior osteoinductive and osseointegration activities compared with the Ti, as assessed by microcomputed tomography and histology. Thus, HAp film on sandblasted Ti plates and screws via Er:YAG-PLD enhances hard-tissue differentiation, macrophage polarization, and new bone formation in tissues surrounding implants both in vitro and in vivo.