Effect of a Er, Cr:YSGG laser and a Er:YAG laser treatment on oral biofilm-contaminated titanium.

Park SH ，Kim OJ ，Chung HJ ，Kim OS ... -  《-》

Comparison of the efficacy of Er,Cr:YSGG laser on oral biofilm removal from implant surfaces with various application times for the treatment of peri-implantitis defects: ex vivo study.

The major struggle in peri-implantitis therapy is the availability of successful decontamination of the infected implant surface. The main hypothesis of this study was the Er,Cr: YSGG laser decontamination efficacy investigation on the infected implant surfaces with various peri-implantitis defects. The primary objective of this study was to decide the efficacy of Er,Cr:YSGG laser as a decontamination tool at various peri-implantitis simulating defects. The secondary objective was to compare the efficacy of the Er,Cr: YSGG laser on oral biofilm removal between two protocols the first protocol (4 cycles at 2.5 min) and the second protocol (5 cycles at 5 min) at various peri-implantitis simulating defects. A total of 3 subjects whose plaque biofilms formed in-vivo on twenty-four tested implants were divided into four tested groups. Two native implants were tested as controls.The in vitro defect model was computer-aided designed and printed into a 3D-printed model with various anulations in peri-implant infrabony defects, which were 15,30,60,and 90 degrees. Both Er, Cr: YSGG decontamination protocols at 50 mJ (1.5 W/30 Hz), 50% air, and 40% water were effective at reducing the total implant surface area/ biofilm ratio (%), but the second protocol had a markedly greater reduction in the duration of application (5 cycles at 5 min) than did the first protocol (4 cycles at 2.5 min). The Er, Cr: YSGG laser is an effective decontamination device in various peri-implantitis defects. The second protocol(5 cycles at 5 min) with greater application time and circles is more effective than the first one. The defect angulation influence the decontamination capability in peri-implantitis therapy. Clinicians anticipate that the exploration of suitable therapeutic modalities for peri-implantitis therapy is limited by the obvious heterogeneity of the available evidence in the literature and need for a pre-clinical theoretical basis setup. The major challenges associated with peri-implantitis therapy include the successful decontamination of the infected implant surface, the absence of any damage to the treated implant surface with adequate surface roughness, and the biocompatibility of the implant surface, which allows osteoblastic cells to grow on the treated surface and is the key for successful re-osseointegration. Therefore, these are the expected empirical triads that need to be respected for successful peri-implantitis therapy. Failure of one of the triads represents a peri-implantitis therapeutic failure. The Er, Cr: YSGG laser is regarded as one of the expected devices for achieving the required triad. "Efficacy of Er,Cr YSGG Laser in Treatment of Peri-implantitis". gov ID NCT05137821. First Posted date: 30 -11-2021.

Hashim A ，Kheir El Din NH ，El-Khazragy N ，Almalahy HG ... -  《BMC Oral Health》

The effect of Er:YAG laser treatment on biofilm formation on titanium and zirconia disc surfaces.

Lasers represent a promising method for implant decontamination, but evidence on implant surface changes and subsequent biofilm formation is limited. This study aimed to assess the effect of erbium-doped yttrium aluminum garnet (Er:YAG) laser treatment on zirconia and titanium discs, and the differences in biofilm formation as a result of surface alterations. A two-stage (in vitro and in vivo) experiment utilizing Er:YAG laser on titanium and zirconia discs was performed. In vitro, surface alterations, roughness, and elemental-material weight differences following laser treatment were assessed using scanning electron microscopy and atomic force microscopy. In vivo, four participants wore custom-made intra-oral stents, embedded with laser-treated and untreated titanium and zirconia discs overnight. Biofilm-coated discs were stained using nucleic acid fluorescence dye and visualized using multiphoton confocal laser scanning microscopy. Biofilm 3D structure, biomass, thickness, and live-to-dead bacteria ratio were assessed. Both titanium and zirconia discs treated with Er:YAG laser resulted in visual surface alterations, but showed no significant change in average surface roughness (titanium P = 0.53, zirconia P = 0.34) or elemental-material-weight (titanium, P = 0.98), (zirconia, P = 0.96). No significant differences in biofilm biomass, average thickness, and live-to-dead bacteria ratio of laser-treated titanium and zirconia discs were identified compared to untreated groups (titanium P > 0.05, zirconia P > 0.05). Generally, zirconia discs presented with a lower live-to-dead bacteria ratio compared to titanium discs, regardless of laser treatment. Er:YAG laser treatment of titanium and zirconia implant surfaces does not significantly affect surface roughness, elemental material weight, or early biofilm formation in the oral cavity.

Assery N ，Alomeir N ，Zeng Y ，Xiao J ，Tsigarida A ... -  《-》

Efficacy of Er:YAG laser irradiation for decontamination and its effect on biocompatibility of different titanium surfaces.

Erbium yttrium-aluminum-garnet (Er:YAG) laser have been shown to be suitable for decontamination of titanium surfaces at a wide range of energy settings, however, high intensity of laser irradiation destroy titanium surface and low intensity cannot remove enough microbial biofilm. The aim of this study was to investigate the optimal energy setting of Er:YAG laser for decontamination of sandblasted/acid-etched (SLA) and hydroxyapatite (HA) titanium surfaces. After supragingival biofilm construction in vivo, SLA and HA titanium discs were divided into three groups: blank control (BC, clean discs), experimental control (EC, contaminated discs) and experimental groups (EP, contaminated discs irradiated by Er:YAG laser at 40, 70, and 100 mJ/pulse). Scanning electron microscopy (SEM), live/dead bacterial fluorescent detection, and colony counting assay were used to detect the efficacy of laser decontamination. To investigate the effect of laser decontamination on titanium surface biocompatibility, MC3T3-E1 cell adhesion and proliferation activity were examined by SEM and CCK-8 assay. Er:YAG laser irradiation at 100 mJ/pulse removed 84.1% of bacteria from SLA titanium surface; laser irradiation at 70 and 100 mJ/pulse removed 76.4% and 77.85% of bacteria from HA titanium surface respectively. Laser irradiation improved MC3T3-E1 cell adhesion on both titanium surfaces. For SLA titanium discs, 100 mJ/pulse group displayed excellent cellular proliferation activity higher than that in BC group (P < 0.01). For HA titanium discs, 70 mJ/pulse group showed the highest activity comparable to BC group (P > 0.05). With regards to efficient microbial biofilm decontamination and biocompatibility maintenance, Er:YAG laser at 100 mJ/pulse and 70 mJ/pulse are considered as the optimal energy settings for SLA titanium and HA titanium surface respectively. This study provides theoretical basis for the clinical application of Er:YAG laser in the treatment of peri-implantitis.

Huang P ，Chen X ，Chen Z ，Chen M ，He J ，Peng L ... -  《BMC Oral Health》

The effects of using erbium, chromium-doped:yttrium-scandium-gallium-garnet laser on the surface modification, bacterial decontamination, and cell adhesion on zirconia discs: an in vitro study.

The use of zirconia for implants and abutments has become more prevalent in implant dentistry as an alternative to the commonly used titanium implants, and peri-implant disease can still affect them. The erbium, chromium-doped:yttrium-scandium-gallium-garnet (Er, Cr:YSGG) laser has emerged as a promising treatment modality. The purposes of this in vitro study were to (1) determine the effects of the laser on the surface roughness of zirconia discs; (2) determine the extent of removal of a single species biofilm, E. coli, on the zirconia discs after applying the laser; (3) determine the amount of cell adhesion and proliferation utilizing fibroblasts on zirconia discs after treatment with the laser. All treatments will be compared with the commonly used ultrasonic instrumentation and hand scalers. For the first aim, gross examination revealed noticeable surface damage on the discs when using ultrasonic and scalers but not for the laser group. For surface roughness, the mean roughness was Pa= 0.623±0.185 μm, 0.762±0.421 μm, 0.740±0.214 μm, and 0.724±0.168 μm for control discs, and discs treated with either the Er,Cr:YSGG laser, ultrasonic instrumentation, and hand scalers respectively. There was no statistical significance among the groups (p=0.628). For bacteria decontamination, there was a statistical significance among the groups (p< 0.0001). Statistical significance was seen between the control group and each of the three treatment groups, favoring the treatment groups (p< 0.0001). Statistical significance was seen when comparing ultrasonic instrumentation and hand scalers (p= 0.000) as well as when comparing the Er,Cr:YSGG laser to hand scalers (p= 0.007), favoring both the ultrasonic instrumentation and Er,Cr:YSGG laser. No significance between the Er,Cr:YSGG laser group and the ultrasonic instrumentation group was noted (p =0.374). When comparing the cell attachment following treatment in each of the three groups and also without treatment (control), there was a statistical significance among the groups (p<0.0001) in terms of total cell count, favoring the control and the laser groups. Further evaluations with SEM showed differences in cell morphology indicating more adherent cells on Er,Cr:YSGG laser-treated surfaces. In conclusion, gross examination of the discs show clear surface changes when using ultrasonic instrumentation and hand scalers compared to the Er,Cr:YSGG laser group. The Er,Cr:YSGG laser was able to effectively ablate bacteria from zirconia disc. Fibroblast attachment on the surfaces of the zirconia discs shows more adherence when treated with Er,Cr:YSGG laser.

Pham CM ，Chen CY ，Kim DM 《-》