Comparative Evaluation of Antimicrobial Effects of Er:YAG, Diode, and CO2 Lasers on Titanium Discs: An Experimental Study

The effects of diode and Er:YAG laser applications on the surface topography of titanium grade 4 and titanium zirconium discs with sand-blasted and acid-etched (SLA) surfaces

BACKGROUND

Laser application for the treatment of peri‑implantitis provides a variety of advantages; however, depending on the laser type and parameters, it may also have adverse effects on the implant surface qualities. This study's objective is to assess the effects of laser type and parameters on the surface properties of two different titanium-based implant materials: titanium Grade 4 (Ti-Grade 4) and titanium zirconium (Ti-Zr) discs with sand-blasted and acid-etched (SLA) surfaces under in vitro conditions.

MATERIAL & METHOD

Sand-blasted and acid-etched discs made of titanium grade 4 (Ti-Grade 4) and titanium zirconium (Ti-Zr) were treated using 808 nm AlGaAs (diode) and 2940 nm Er:YAG lasers with varying parameters (i.e., diode laser in continuous wave mode, Er:YAG in short pulse mode, and Er:YAG in variable square pulse mode with four different doses). Then, the surface morphology and topography of the treated discs were characterized using scanning electron microscopy and optical profilometry.

RESULTS

The 3D surface topographies of discs treated with a high power Er:YAG laser displayed irregular peaks and deep valleys, indicating surface deterioration. The average surface roughness values (Sa) of both discs varied with laser type and parameters (3.55-4.80 µm for Ti-Grade 4 versus 3.25-4.5 µm for Ti-Zr). With diode laser applications, the topography features of the discs were preserved despite a small number of irregular valleys and peaks. However, the surface morphologies of the discs were dramatically altered by erosion and local melting because of the Er:YAG laser treatment.

CONCLUSION

Diode laser application appears to be the most reliable method for treating peri‑implantitis, as diode laser-treated implants retained their overall surface quality despite a small number of irregular peaks and valleys.

Effectiveness of mechanical and chemical decontamination methods for the treatment of dental implant surfaces affected by peri-implantitis: A systematic review and meta-analysis

OBJECTIVE

To assess which decontamination method(s) used for the debridement of titanium surfaces (disks and dental implants) contaminated with bacterial, most efficiently eliminate bacterial biofilms.

MATERIAL AND METHODS

A systematic search was conducted in four electronic databases between January 1, 2010 and October 31, 2022. The search strategy followed the PICOS format and included only in vitro studies completed on either dental implant or titanium disk samples. The assessed outcome variable consisted of the most effective method(s)-chemical or mechanical- removing bacterial biofilm from titanium surfaces. A meta-analysis was conducted, and data was summarized through single- and multi-level random effects model (p < .05).

RESULTS

The initial search resulted in 5260 articles after the removal of duplicates. After assessment by title, abstract, and full-text review, a total of 13 articles met the inclusion criteria for this review. Different decontamination methods were assessed, including both mechanical and chemical, with the most common method across studies being chlorhexidine (CHX). Significant heterogeneity was noted across the included studies. The meta-analyses only identified a significant difference in biofilm reduction when CHX treatment was compared against PBS. The remaining comparisons did not identify significant differences between the various decontamination methods.

CONCLUSIONS

The present results do not demonstrate that one method of decontamination is superior in eliminating bacterial biofilm from titanium disk and implant surfaces.

Effect of Electrocautery and Laser Treatment on the Composition and Morphology of Surface-Modified Titanium Implants

The purpose of this study was to investigate the effects of different peri-implantitis treatment methods (Er,Cr:YSGG laser, diode laser, and electrocautery) on various titanium implant surfaces: machined; sandblasted, large-grit, and acid-etched; and femtosecond laser-treated surfaces. Grade 4 titanium (Ti) disks, with a diameter of 10 mm and a thickness of 1 mm, were fabricated and treated using the aforementioned techniques. Subsequently, each treated group of disks underwent different peri-implantitis treatment methods: Er,Cr:YSGG laser (Biolase, Inc., Foothill Ranch, CA, USA), diode laser (Biolase, Inc., Foothill Ranch, CA, USA), and electrocautery (Ellman, Hicksville, NY, USA). Scanning electron microscopy, energy-dispersive X-ray spectroscopy, and wettability were used to characterize the chemical compositions and surfaces of the treated titanium surfaces. Significant changes in surface roughness were observed in both the electrocautery (Sa value of machined surface = 0.469, SLA surface = 1.569, femtosecond laser surface = 1.741, and p = 0.025) and Er,Cr:YSGG laser (Ra value of machined surface = 1.034, SLA surface = 1.380, femtosecond laser surface = 1.437, and p = 0.025) groups. On femtosecond laser-treated titanium implant surfaces, all three treatment methods significantly reduced the surface contact angle (control = 82.2°, diode laser = 74.3°, Er,Cr:YSGG laser = 73.8°, electrocautery = 76.2°, and p = 0.039). Overall, Er,Cr:YSGG laser and electrocautery treatments significantly altered the surface roughness of titanium implant surfaces. As a result of surface composition after different peri-implantitis treatment methods, relative to the diode laser and electrocautery, the Er,Cr:YSGG laser increased oxygen concentration. The most dramatic change was observed after Er:Cr;YSGG laser treatment, urging caution for clinical applications. Changes in surface composition and wettability were observed but were not statistically significant. Further research is needed to understand the biological implications of these peri-implantitis treatment methods.

Enhanced antibacterial activity of cadmium telluride nanocrystals in combination with 940-nm laser diode on anaerobic bacteria P. gingivalis: an in vitro study

Periodontal disease is one of the most common chronic diseases in the oral cavity that causes tooth loss. Root scaling and leveling cannot eliminate all periodontal pathogens, and the use of antibacterial agents or lasers can increase the efficiency of mechanical methods. The aim of this study was to evaluate and compare the antibacterial activity of cadmium telluride nanocrystals in combination with 940-nm laser diode. Cadmium telluride nanocrystals were prepared by a green route of synthesis in aqueous medium. The results of this study showed that cadmium telluride nanocrystals significantly inhibit the growth of P. gingivalis. The antibacterial property of this nanocrystal increases with increasing its concentration, laser diode 940-nm irradiation and with increasing the time. It was shown that the antibacterial activity of combination of 940-nm laser diode and cadmium telluride nanocrystals is greater than the effect of either alone and can have a similar effect with its long-term presence of microorganisms. This is very important because it is not possible to use these nanocrystals in the mouth and in the periodontal bag for a long time.

Carbon Dioxide Laser Sequestrectomy for Osteoradionecrosis: A Case Series

Objective: To demonstrate a new approach to sequestrectomy using a carbon dioxide (CO₂) laser for a clinic-based technique. Background: Osteoradionecrosis (ORN) of the jaw is a debilitating complication of radiotherapy for head and neck malignancies. Often refractory to medical therapy, surgical intervention for early staged disease with curettage and mechanical bone removal has mixed success, making this disease extremely difficult to treat. Therefore, new approaches to treat ORN of the jaw is needed. Methods: We describe five cases of early-to-intermediate-staged ORN illustrating a novel clinic-based sequestrectomy technique using a CO₂ laser. Results: The exposed bone lesions involved the mandibular fixed gingiva, maxillary fixed gingiva, and hard palate. None of the patients had diabetes. Four patients required a total of two laser treatments and one patient needed only one treatment. All five patients demonstrated an excellent response with complete resolution of their ORN-related pain and complete mucosal coverage of the exposed bone with durable results (follow-up range, 7-19 months). Conclusions: This small series demonstrates encouraging results for CO₂ laser sequestrectomy for ORN. This novel office-based intervention merits further study in larger prospective series and exploration in other disease populations, such as medication-related osteonecrosis of the jaws.

Efficacy of Er:YAG laser for the peri-implantitis treatment and microbiological changes: a randomized controlled trial

The aims of this study were to identify the microbiological changes in the periodontal pockets following an Er:YAG laser (ERL) irradiation and mechanical debridement to compare the effectiveness of ERL irradiation to mechanical debridement for peri-implantitis treatment through randomized controlled trials. Twenty-three patients with peri-implantitis lesions were treated in either a test group, ERL set at energy level of 100 mJ/pulse, frequency of 10 Hz, pulse duration was 100 µs, and irradiated by three passages, or a control group, with mechanical debridement using an ultrasonic scaler. An examiner measured the following clinical parameters at different stages (a baseline and at 3- and 6-month post-treatment): probing depth (PD), bleeding on probing (BOP), marginal bone loss (MBL), and anaerobic bacteria counts. Linear regression, with generalized estimation equations, was used to compare the clinical parameters and anaerobic bacterial counts at different stages and between groups. The anaerobic bacterial counts significantly decreased within the control group during the follow-ups. At the 6-month follow-up, both groups showed a significant reduction in PD (test group: mean difference of 0.84 mm; control group: mean difference of 0.41 mm), and the test group showed a significantly higher PD reduction on the buccal site (1.31 mm) compared to that of the control group (0.25 mm). Both ERL and mechanical debridement treatments led to significant improvements in PD. When mechanical debridement therapy was used, significant anaerobic bacterial count reductions were observed. Future treatment of peri-implantitis should involve a combination of both of these therapies.

Efficacy of an Er:YAG laser in the decontamination of dental implant surfaces: An in vitro study

BACKGROUND

Emergence of peri-implant diseases led to the development of various methods for implant surface decontamination. This study was designed to compare the efficacy of biofilm removal from implant-like titanium surfaces by an erbium-doped yttrium-aluminum-garnet (Er:YAG) laser, titanium brush, and carbon fiber curet.

METHODS

Eight study subjects were recruited. A custom mouth appliance that held eight sandblasted and acid-etched titanium discs was fabricated for each subject. Subjects were asked to wear this appliance for 72 hours to allow for biofilm development. After retrieval, discs were removed and randomized to one of four treatment groups. The discs were stained with a two-component nucleic acid dye kit, and the residual biofilm was visualized under fluorescence microscopy. Quantification of residual biofilm was performed using an image analysis software and expressed as the percentage surface area.

RESULTS

Fifty-nine titanium discs were randomized to the four treatment groups. The percentage of titanium disc area covered by residual biofilm was 74.0% ± 21.6%, 32.8% ± 24.0%, 11.8% ± 10.3%, and 20.1% ± 19.2% in the control, Er:YAG, titanium brush and carbon fiber curet groups, respectively (mean ± SD). The biofilm-covered area significantly decreased in each of the three treatment groups compared with control (P < 0.008). Comparisons between treatment groups did not reveal statistical significance.

CONCLUSIONS

Er:YAG laser treatment is an effective method for reducing the bacterial biofilm on titanium discs. However, on a threadless titanium surface, Er:YAG laser does not exhibit a significantly greater efficacy in biofilm removal than commonly used titanium brushes or carbon fiber curets.

Bacterial reduction effect of four different dental lasers on titanium surfaces in vitro

Compare the effectiveness of selected dental lasers for decontamination of machined titanium surfaces in vitro. Seventy-two sterile machined surface titanium discs were individually inoculated with strains of Streptococcus mutans (Sm), Streptococcus oralis (So), Aggregatibacter actinomycetemcomitans (Aa), or all three bacteria together (MIX) at 34.0^° C, 20.8% O₂ and 5% CO₂ for 12 h. After incubation, the discs were divided into six groups: 1) no treatment, 2) 0.12% chlorhexidine gluconate (CHX), and 3) 10,600 CO₂, 4) 810 nm diode, 5) 2780 nm Er,Cr:YSGG, 6) 1064 nm Nd:YAG laser groups. After treatment, any remaining viable bacteria were liberated from the discs via sonication, transferred onto brain heart infusion (BHI) agar plates for culturing, and colony-forming units (CFUs) were recorded. Statistical analysis was performed. There were statistically significantly differences (SSD) (p < 0.01) in bacterial reduction of discs individually inoculated with Aa between the Er,Cr:YSGG and Nd:YAG lasers. There was also a SSD (p < 0.01) lower effect with the MIX with the Er,Cr:YSGG compared with all other modalities. Bacterial reduction with the CO₂ was better (p < 0.001) than treatment with CHX or the Er,Cr:YSGG laser on killing of So. Although all modalities of treatment showed a mean of 98% or greater viable bacterial reduction, the most consistent bacterial reduction of all titanium discs was with the Nd:YAG laser (100%).

Laser Therapy in the Treatment of Peri-Implantitis: State-of-the-Art, Literature Review and Meta-Analysis

(1) Background: The treatment of the peri-implantitis is still challenging, and no consensus was found in the literature on which is the best treatment protocol. In recent years, numerous authors have proposed the use of the dental laser as an alternative and effective method for decontaminating the surface of infected implants. Therefore, the aim of this work was to examine the state-of-the-art on the use of lasers in the treatment of peri-implantitis through the literature. (2) Methods: An electronic search was conducted through the PubMed database; we selected and reviewed articles that evaluated the effects of laser irradiation in the treatment of peri-implantitis. (3) Results: The use of lasers seems to provide similar results if compared with conventional mechanical therapy. The included studies were divided into three groups based on the active medium of the laser used for the treatments being tested (Erbium: Yttrium Aluminum Garnet, CO2 and diode laser). (4) Conclusions: The lasers showed positive results, on average, after 6 months of follow-up. Comparative clinical trials conducted with the aim to test the efficiency of laser irradiation, in addition to conventional therapy, indicate that this technique can induce similar results if compared to conventional therapy alone.

In vitro efficacy of biofilm removal from titanium surfaces using Er:YAG laser: Comparison of treatment protocols and ablation parameters

BACKGROUND

The aims of the present study were to compare the antibacterial effect of Er:YAG laser with other acceptable decontamination methods and to single out the optimal laser device parameters for effective bacterial elimination.

METHODS

A multispecies biofilm which was composed of Streptococcus sanguis, Actinomyces naeslundii, Porphyromonas gingivalis, and Fusobacterium nucleatum was grown on sandblasted and acid-etched (SLA, homogeneous moderately microrough, and nanosmooth surface) titanium disks. The biofilm was removed from the coated disks by hand curets, ultrasonic device, nylon brush (dental polishing prophy cup), or Er:YAG. Additionally, different parameter combinations of the laser machine were examined to reach an optimal lasing power for bacterial elimination/reduction. Residual biofilm samples were stained with bacterial live/dead staining and quantified using a fluorescent microscope.

RESULTS

A multispecies biofilm was accumulated on the SLA titanium surfaces exhibiting cluster distribution next to bacteria-poor areas. Hand curets, nylon brushes, and the ultrasonic device showed limited capability to effectively remove the biofilm from the SLA surfaces as opposed to the Er:YAG which displayed a superior ability to remove the biofilm. All Er:YAG parameter combinations that were evaluated as well as the tested "tip to target" distances showed similar excellent anti-biofilm effects. Furthermore, we observed that the Er:YAG capability of biofilm removal is not only due to its light emission, but depends on its water irrigation as well.

CONCLUSIONS

Er:YAG laser has an excellent biofilm removal capability compared with hand curets, ultrasonic devices, or nylon brushes even when low energy parameters and low power settings are used. Additionally, an excellent antibacterial effect can be reached using a non-contact mode of 1 to 5 mm "tip to target" distance.

Application of a Medical Diode Laser (810 nm) for Disinfecting Small Microbiologically Contaminated Spots on Degraded Collagenous Materials for Improved Biosafety in Objects of Exceptional Historical Value From the Auschwitz-Birkenau State Museum and Protection of Human Health

The research aim was to optimize the operating parameters of a diode laser irradiation for the effective disinfection of degraded collagenous materials. Historical leather shoes stored at the Auschwitz-Birkenau State Museum in Oświęcim (Poland) were the main study objects. Surfaces of contaminated small spots occurring on the degraded materials were sampled with moistened swabs and microbiologically examined using the molecular techniques MALDI-TOF MS, 16S rRNA, and NGS sequencing. The surfaces were colonized by bacteria with 10⁶ CFU/100 cm² and 10⁴ CFU/100 cm² by fungi, on average. Microorganisms of the genera Bacillus and Penicillium were predominant. The effectiveness of the laser treatment was assessed for the new and degraded collagenous materials against isolated environmental strains using four variants of exposure time and number of repetitions. 0.3 W/CW 2 × 2 min variant was the most effective and also did not noticeably change the color of the treated samples. The variant caused a reduction in the numbers of microorganisms by 96–100%. After 1 month, four types of leather were subjected to comprehensive physico-chemical analyses. SEM and FTIR techniques confirmed that laser irradiation in the selected optimal variant did not affect the surface morphology and collagen structure, while XPS technique enabled detection of subtle changes in non-historical protective coatings on the surfaces of tested degraded historical materials.

Efficacy of different lasers of various wavelengths in treatment of peri-implantitis and peri-implant mucositis: A systematic review and meta-analysis

Aim

Peri implant diseases lead to pathological changes in the peri implant tissues and loss of osseointegration. The purpose of this analysis is to evaluate the effect of various lasers and photodynamic therapy (PDT) on peri implant diseases compared to conventional procedures.

Setting and Design

This meta analysis was conducted as per the Preferred Reporting Items for Systematic Reviews and Meta Analyses guidelines.

Materials and Methods

A systematic search of the electronic databases such as PubMed, ICTRP, CT.gov, Embase, and Cochrane Library was done additional to manual search of peer review article on peri-implant diseases. Eleven randomized control clinical trials were included in which laser therapy and PDT were used as an interventional procedure.

Results and Statistical Analysis Used

Review Manager 5.03 (RevMan, Nordic Cochrane Center, Copenhagen, Denmark), and random effects model were used to assess mean difference (MD). Bivariate differential mean statistic was used in intergroup estimate with 95% confidence interval (CI). I2 test statistics was applied for heterogenity and P < 0.05 was considered significant statistically. The literature search yielded a total of 113 articles among which 11 articles were included for quantitative analysis. The selected outcome PD reported MD -0.01 with 95% CI (-0.13, 0.16), P = 0.84, and CAL reported MD -0.09 with 95% CI (-0.32, 0.14), P = 0.45, respectively.

Conclusion

Laser treatment as an adjunctive therapy or monotherapy in peri implantitis does not show any superior effects than conventional measures as per evidence. However, cases with peri implant mucositis have shown far more promising results with laser therapy compared to peri implantitis.

The Effects of Erbium-Doped Yttrium Aluminum Garnet Laser (Er: YAG) Irradiation on Sandblasted and Acid-Etched (SLA) Titanium, an In Vitro Study

The treatment of peri-implantitis implies the decontamination of the surface of the fixture. This study aims to analyze the effect of the erbium-doped yttrium aluminum garnet laser (Er: YAG) on sandblasted and acid-etched (SLA) titanium. 30 titanium SLA disks were divided into three groups. In Group 1, the disks were left intact; on the contrary, both Groups 2 and 3 were irradiated with the Er: YAG laser at different settings, with a pulse duration of 300 μs and a period of 30 s. Group 2 was irradiated at 1 W and 100 mJ/pulse and Group 3 at 4 W and 400 mJ/pulse. The superficial changes at chemical, nano, and microscopical levels were detected through the use of Fourier-transform infrared spectroscopy, atomic force microscopy, and scanning electron microscope. The Kruskal–Wallis test, followed by the Dunn–Bonferroni Post Hoc analysis, detected the presence of statistically significant differences among the groups. The level of significance was p ≤ 0.05. Results showed that Er: YAG irradiation promoted a significant (p < 0.05) increase of oxides and a decrease of microscopical roughness and porosity on SLA disks. However, the protocol tested on group 3 seemed to be too aggressive for the titanium surface, as shown by the presence of micro-cracks and signs of coagulation, melting, and microfractures. In conclusion, Group 2 showed significantly minor surface alterations with respect to Group 3, and the increase of superficial oxide level, the decrease of porosity, and micro-roughness represent a positive alteration that could protect the materials against bacterial adhesion.

Laser-assisted regenerative surgical therapy for peri-implantitis: A randomized controlled clinical trial

BACKGROUND

Different surgical approaches have been proposed to treat peri-implantitis defects with limited effectiveness and predictability. Laser has been proposed as an effective tool to assist in bacterial decontamination and modulating peri-implant tissue inflammation. The aim of this pilot clinical trial was to evaluate the adjunctive benefits of Er:YAG laser irradiation for regenerative surgical therapy of peri-implantitis-associated osseous defects.

METHODS

Twenty-four patients diagnosed with peri-implantitis with a radiographic infrabony defect were randomized into two groups. Both test and control groups received the following treatment: open flap mechanical debridement, supracrestal implantoplasty, bone grafting using a mixture of human allograft with demineralized bone matrix human allograft putty, and then covered with acellular dermal matrix membrane. The only difference in the test group was the adjunctive use of Er:YAG laser to modulate and remove inflammatory tissue as well as to decontaminate the implant surface. Clinical assessments, including pocket depth (PD), clinical attachment level (CAL), and gingival index (GI) were performed by calibrated masked examiners for up to 6 months following surgery. Standardized radiographs were also taken to evaluate linear bone gain and defect bone fill. Student t-tests were used to analyze those clinical parameters.

RESULTS

Both groups showed significant reductions in PD, GI, and CAL gain overtime. The test group demonstrated significantly higher PD reductions at the site level compared to the control group (2.65 ± 2.14 versus 1.85 ± 1.71 mm; test versus control, P = 0.014). There were no statistical differences found in CAL gain (1.90 ± 2.28 versus 1.47 ± 1.76 mm; test versus control), GI reduction (-1.14 ± 1.15 versus -1.04 ± 0.89; test versus control), radiographic linear bone gain (1.27 ± 1.14 versus 1.08 ± 1.04 mm; test versus control) or proportional defect size reduction (- 24.46 ± 19.00% versus -15.19 ± 23.56%; test versus control). There was a positive trend for test patients on PD reduction and CAL gain found in narrow infrabony defects. Major membrane exposure negatively impaired the overall treatment outcome of CAL gain (2.47 ± 1.84 versus 1.03 ± 1.48 mm; no/minor versus major exposure, P = 0.051) and PD reduction in the test group (-3.63 ± 2.11 versus -1.66 ± 1.26 mm, P = 0.049).

CONCLUSION

This pilot study indicated using laser irradiation during peri-implantitis regenerative therapy may aid in better probing PD reduction. Nonetheless, a larger sample size and longer follow-up is needed to confirm if Er:YAG laser irradiation provides additional clinical benefits for peri-implantitis regenerative therapy (Clinicaltrials.gov: NCT03127228).

A Study to Evaluate the Efficacy of an 810-nm Diode Laser in the Maintenance of Dental Implants: A Peri-Implant Sulcular Fluid Analysis

Biological implant failures are primarily related to biofilm, which can lead to peri-mucositis and, further on, peri-implantitis. The 810-nm diode laser has an affinity for pigmented chromophores, so its use in the peri-implant sulcus has a significant bactericidal effect on the black-pigmented anaerobes such as Porphyromonas gingivalis. Therefore, it can be used to eliminate or reduce the bacterial count in the peri-implant sulcular fluid (PISF), thus increasing the life of the implants and reducing the chances of failure. The purpose of this study was to evaluate the efficacy of the 810-nm diode laser for the maintenance of dental implants and its use as a regular in-office tool for limiting the microbiological count in the PISF. Twenty patients undergoing implant treatment at the Department of Periodontology and Oral Implantology were randomly selected for the study. PISF samples were collected before and after the sulcus was lased with an 810-nm diode laser and sent for quantitative microbiological analysis using universal bacterial count, and the quantity of P gingivalis was evaluated using real-time polymerase chain reaction (PCR). The analysis revealed that after diode application, the median percentage drop in the microbial count was 76.67% and the median percentage drop in P gingivalis count was 99.28%. The use of an 810-nm diode laser resulted in the following outcomes: (1) drastic reduction in the total bacterial count around the implant and (2) significant reduction in the P gingivalis count, as evaluated by real-time PCR.

First Investigation of Dual-Wavelength Lasers (2780 nm Er,Cr:YSGG and 940 nm Diode) on Implants in a Simulating Peri-Implantitis Situation Regarding Temperature Changes in an In Vitro Pocket Model

Objective: This study aimed to investigate the temperature changes and question the safe laser settings and protocols for laser-assisted peri-implantitis treatment in an in vitro environment. Materials and methods: Three types of implants (Neoss, Dentegris, and Camlog) were implanted in an artificial bone model (n = 15). The model was placed into a 37°C water bath to simulate the in vivo oral condition. Throughout the laser irradiation, K-type thermocouples were used to record the real-time temperature measurements at different anatomically important locations in the artificial bone. Results: In all of the temperature measurements, no temperature rise above the critical safe limit, that is, >47°C, was observed. Conclusions: Within the limitations of this in vitro study, the use of the dual-wavelength protocol [Er,Cr:YSGG (1 and 1.5 W, 25, 50, 75 Hz)] and the 940 nm diode (peak power 2 W, duty cycle 50%) can be considered a safe method in the treatment of peri-implantitis, regarding its thermal safety.

Effect of 5 Popular Disinfection Methods on Microflora of Laboratory: Customized Implant Abutments

PURPOSE

To compare the efficacy of 5 different decontamination methods of titanium abutments and to assess their possible effects on surface roughness of titanium.

MATERIALS AND METHODS

Micrococcus luteus, Acinetobacter baumannii, Enterococcus faecalis, and Candida albicans were cocultured to form a multispecies biofilm on 18 titanium discs. In another group, Bacillus subtilis, a spore-forming species, was cultivated on another set of 18 titanium discs. Each group was further divided into 5 test groups: high-pressure steam cleaning (4 Mpa, 5 seconds), NaOCl (1% active chlorine, 5 minutes), H2O2 (3%, 5 minutes), GaAlAs laser (810 nm, CW, 1 W, 400-μm fiber, 1-mm distance, 1 minute), Er:YAG laser (2940 nm, pulse mode, 100 mJ, 10 Hz, 230-μm noncontact handpiece, 4-mm distance, 50/50% air/water, 1 minute), and a control group of no treatment. After each decontamination procedure, the remaining microbial load was reported as colony-forming unit/disc. To evaluate the effect of each treatment on titanium discs, surface roughness parameters including Sa, Sq, Ssk, Sku, Sal, and Sdr were measured at 6 points of each disc using an atomic force microscope.

RESULTS

Complete disinfection was achieved using high-pressure steam, NaOCl, H2O2, and Er:YAG laser. GaAlAs laser was able to reduce microbial count over 90%. Sa and Sq parameters were only increased significantly in diluted NaOCl group in comparison with control group, whereas Sdr was increased significantly in both absolute and diluted NaOCl groups.

CONCLUSION

All the methods could decontaminate machined titanium surfaces, although complete microbial elimination was not achieved by diode laser. None of the treatments altered surface roughness significantly, except for sodium hypochlorite (NaOCl).

Mineral Trioxide Aggregate Mixed with 5-Aminolevulinic Acid for the Photodynamic Antimicrobial Strategy in Hard Tissue Regeneration

Aminolevulinic acid (ALA) based photodynamic antimicrobial strategy can provide good antimicrobial effects and be used for medical applications. The aim of this study was to apply this strategy to Mineral Trioxide Aggregate (MTA), which is commonly used as a filling material for root endings and by doing so, to increase the bactericidal capability of MTA, as well as to investigate its characterization, cytocompatibility, and odontogenic differentiation potential. MTA is known to be a derivative of calcium silicate (CS). In this study, MTA specimens with or without ALA and light treatment were prepared. Diametral tensile strength values (DTS), setting durations, X-ray diffraction (XRD) spectra, apatite-mineralization, and antimicrobial abilities of the MTA, were also analyzed. Human dental pulp cells (hDPCs) can proliferate into the newly formed matrix and differentiate into odontoblasts to reinforce and strengthen the root. Levels of hDPCs proliferation and its odontogenic capabilities when cultured on MTA with ALA and light treatment, and the percentages of cells existing in the various cell cycle stages, were further evaluated in this study. The results indicated that MTA added ALA with light treatment had greater antibacterial ability and cytocompatibility, compared to MTA alone. A higher percentage S phase of the cells cultured on MTA added ALA with light treatment was observed. Furthermore, hDPCs cultured on MTA added ALA with light treatment had the highest expression levels of the odontoblastic differentiation markers. ALA has great antimicrobial efficiency and is a potential material for future medical applications. ALA-based photodynamic antibacterial strategy applied in the MTA has great antibacterial ability, cytocompatibility, and odontoblastic differentiation potential, and can facilitate the development of root canal treatment.

Antimicrobial efficacy of photodynamic therapy and light-activated disinfection on contaminated zirconia implants: An in vitro study

BACKGROUND

We aimed to evaluate the antimicrobial efficacy of photodynamic therapy (PDT) and light-activated disinfection (LAD) on zirconia dental implants contaminated with three bacterial species and investigate if the PDT and LAD cause implant surface alterations.

METHODS

Seventy-two zirconia dental implants were contaminated with a bacterial suspension of Prevotella intermedia, Actinomyces actinomycetemcomitans, and Porphyromonas gingivalis. The implants were subsequently randomly divided into four groups (n = 12 dental implants/each) according to the decontamination protocol: Group 1 (PDT1) - PDT (660 nm, 100 mW) with toluidine blue; Group 2 (PDT2) - PDT (660 nm, 100 mW) with phenothiazine chloride dye; Group 3 (LAD) - light emitting diode (LED) with toluidine blue; and Group 4 (TB) - toluidine blue without the application of light. Implants in the positive control (PC) group were treated with a 0.2% chlorhexidine-based solution, and implants assigned to the negative control (NC) group did not undergo any treatment. Each implant was then placed in tubes containing phosphate buffered saline (PBS) and vortexed for 60 s to remove the remaining bacteria from the implant surface. After 10-fold serial dilutions, 30 μl of the suspension was plated on Brucella agar plates. After 72 h, the colony forming units (CFU) were counted. Distinctive colonies were confirmed with MALDI Biotyper. The implants were analyzed using scanning electron microscope (SEM) to evaluate the possible surface alterations due to PDT or LAD.

RESULTS

All study groups had significant reductions in the number of CFUs compared with the NC (p < 0.05). PDT1, the PDT2, and the LAD groups had the largest bacterial reduction with respect to each bacterial species separately and the total bacterial count, and they were more efficient compared with the TB group (p < 0.05). SEM analysis did not reveal any alterations of the implant surface after the treatment procedures.

CONCLUSION

Both PDT protocols and LAD showed high and equal effectiveness in decontamination of zirconia dental implants.

Thermodynamic effects after Diode and Er:YAG laser irradiation of grade IV and V titanium implants placed in bone - an ex vivo study. Preliminary report

Many inserted implants are affected by peri-implantitis. The aim of our study was to evaluate increases in implant temperature, depending on the diameter and chemical composition of implants. In particular we measured the time it takes for the temperature of an implant to rise by 10°C and evaluated laser power settings required to prevent thermal injury when an implant surface is decontaminated during the treatment of peri-implantitis. The study analysed six implants placed in porcine ribs and divided into two groups according to their diameter and chemical composition (grade IV and grade V titanium). The implants were irradiated with Diode and Er:YAG lasers using different laser parameters. The temperature was measured with a K-type thermocouple. The temperature on the implant surface rose as the laser power increased and the implant diameter decreased. The time required to increase the temperature of an implant by 10°C was less than it was for titanium grade IV. The temperature gradient was below 10°C for all implants treated using a laser power up to 1 W. It is important to choose the correct laser parameters, depending on the chemical composition and diameter of the implant, so that decontamination of the implant surface is thorough, effective and safe.

Effects of Two Diode Lasers With and Without Photosensitization on Contaminated Implant Surfaces: An Ex Vivo Study

OBJECTIVE

The aim of this ex vivo study is to assess decontamination potential of two different diode laser wavelengths, with or without the aid of photodynamic therapy, on dental implant surfaces and to evaluate the harmful potential of temperature increase during laser irradiation.

MATERIALS AND METHODS

One hundred thirty-two machined sterile implants were placed into sterile porcine bone blocks with standardized coronal angular bony defects and inoculated with Streptococcus sanguinis. Four different treatment protocols were used: 810 or 980 nm laser, with or without photosensitization. Two nontreated control groups were used, one with samples coated with indocyanine green dye. Samples were rinsed and plated on agar plates for subsequent colony count. Irradiation was repeated without contamination at room temperature and in a 37°C water bath monitoring the temperature variation.

RESULTS

There is a statistically significant decontamination effect when the laser is used. Both wavelengths minimize contamination. There was modest improvement given by the photosensitization being more marked in the 810 nm groups, but was not statistically significant compared to laser only. A critical temperature increase was never observed when the sample was in a 37°C water bath.

CONCLUSIONS

The use of both diode laser wavelengths in implant surface decontamination was efficacious regardless of the use of photosensitization and without dangerous increase of temperature.

Periodontal and peri-implant wound healing following laser therapy

Laser irradiation has numerous favorable characteristics, such as ablation or vaporization, hemostasis, biostimulation (photobiomodulation) and microbial inhibition and destruction, which induce various beneficial therapeutic effects and biological responses. Therefore, the use of lasers is considered effective and suitable for treating a variety of inflammatory and infectious oral conditions. The CO2 , neodymium-doped yttrium-aluminium-garnet (Nd:YAG) and diode lasers have mainly been used for periodontal soft-tissue management. With development of the erbium-doped yttrium-aluminium-garnet (Er:YAG) and erbium, chromium-doped yttrium-scandium-gallium-garnet (Er,Cr:YSGG) lasers, which can be applied not only on soft tissues but also on dental hard tissues, the application of lasers dramatically expanded from periodontal soft-tissue management to hard-tissue treatment. Currently, various periodontal tissues (such as gingiva, tooth roots and bone tissue), as well as titanium implant surfaces, can be treated with lasers, and a variety of dental laser systems are being employed for the management of periodontal and peri-implant diseases. In periodontics, mechanical therapy has conventionally been the mainstream of treatment; however, complete bacterial eradication and/or optimal wound healing may not be necessarily achieved with conventional mechanical therapy alone. Consequently, in addition to chemotherapy consisting of antibiotics and anti-inflammatory agents, phototherapy using lasers and light-emitting diodes has been gradually integrated with mechanical therapy to enhance subsequent wound healing by achieving thorough debridement, decontamination and tissue stimulation. With increasing evidence of benefits, therapies with low- and high-level lasers play an important role in wound healing/tissue regeneration in the treatment of periodontal and peri-implant diseases. This article discusses the outcomes of laser therapy in soft-tissue management, periodontal nonsurgical and surgical treatment, osseous surgery and peri-implant treatment, focusing on postoperative wound healing of periodontal and peri-implant tissues, based on scientific evidence from currently available basic and clinical studies, as well as on case reports.

Thermodynamic Effects of 3 Different Diode Lasers on an Implant-Bone Interface: An Ex-Vivo Study With Review of the Literature

The aim of this study is to assess the increase of temperature following laser irradiation with 810 nm, 980 nm, and 1064 nm diode laser wavelengths, of an implant under conditions that more closely replicate those of the human body. A 4 × 14 mm machined surface implant was placed in a porcine rib to replicate the conductivity of heat given by the bone. A peri-implant vertical defect was made that was 2 mm wide and 2 mm deep to simulate bone resorption. Two thermocouples were positioned crestally and apically on the implant surface. The tip of the laser was kept 3 mm away from the surface and continuously moved in an up-and-down and side-to-side fashion, inside the defect for 60 seconds. Initial temperatures and the time needed to reach an increase of 10°C were recorded. The experiment was repeated at room temperature and in a 37°C water bath with the following settings: 0.6 W, 0.8 W, 1 W continuous and repeated in pulsed. A critical increase of temperature of more than 10°C is reached with all lasers at 0.8 W and 1 W in continuous mode at room temperature. Only the 1064 nm diode laser reached the critical increase at 0.8 W in pulsed mode. No critical increase of temperature was registered with other settings and when the bone block was placed in a 37°C water bath. The results of this study suggest that use of these diode lasers does not cause a harmful increase in temperature when used under conditions similar to those of the human body.

Temperature evaluation of dental implant surface irradiated with high-power diode laser

The prevalence of peri-implantitis and the absence of a standard approach for decontamination of the dental implant surface have led to searches for effective therapies. Since the source of diode lasers is portable, has reduced cost, and does not cause damage to the titanium surface of the implant, high-power diode lasers have been used for this purpose. The effect of laser irradiation on the implants is the elevation of the temperature surface. If this elevation exceeds 47 °C, the bone tissue is irreversibly damaged, so for a safety therapy, the laser parameters should be controlled. In this study, a diode laser of GaAsAl was used to irradiate titanium dental implants, for powers 1.32 to 2.64 W (real) or 2.00 to 4.00 W (nominal), in continuous/pulsed mode DC/AC, with exposure time of 5/10 s, with/without air flow for cooling. The elevation of the temperature was monitored in real time in two positions: cervical and apical. The best results for decontamination using a 968-nm diode laser were obtained for a power of 1.65 and 1.98 W (real) for 10 s, in DC or AC mode, with an air flow of 2.5 l/min. In our perspective in this article, we determine a suggested approach for decontamination of the dental implant surface using a 968-nm diode laser.

Bactericidal efficacy of tissue tolerable plasma on microrough titanium dental implants: An in-vitro-study

Surface decontamination remains challenging in peri-implant infection therapy. To investigate the bactericidal efficacy of tissue tolerable plasma, S. mitis biofilms were created in vitro on 32 microrough titanium dental implants. Biofilm imaging was performed by confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM). The implants were either rinsed with 1% NaCl as negative control (C) or irradiated with a diode laser (DL) for 60 sec as positive control or plasma (TTP60, TTP120) for 60 or 120 sec. Subsequently, colony forming units (CFU) were counted. Post-treatment, implants were further examined using fluorescence microscopy (FM). Median CFU counts differed significantly between TTP60, TTP120 and C (2.19 and 2.2 vs. 3.29 log CFU/ml; p = 0.012 and 0.024). No significant difference was found between TTP60 and TTP120 (p = 0.958). Logarithmic reduction factors were (TTP60) 2.21, (TTP120) 1.93 and (DL) 0.59. Prior to treatment, CLSM and SEM detected adhering bacteria. Post-treatment FM recorded that the number of dead cells was higher using TTP compared to DL and C. In view of TTP's effectiveness, regardless of resistance patterns and absence of surface alteration, its use in peri-implant infection therapy is promising. The results encourage conducting clinical studies to investigate its impact on relevant parameters.

Applications of Light Amplification by Stimulated Emission of Radiation (Lasers) for Restorative Dentistry

Light amplification by stimulated emission of radiation (laser) has been used widely in a range of biomedical and dental applications in recent years. In the field of restorative dentistry, various kinds of lasers have been developed for diagnostic (e.g. caries detection) and operative applications (e.g. tooth ablation, cavity preparation, restorations, bleaching). The main benefits for laser applications are patient comfort, pain relief and better results for specific applications. Major concerns for using dental lasers frequently are high cost, need for specialized training and sensitivity of the technique, thereby compromising its usefulness particularly in developing countries. The main aim of this paper is to evaluate and summarize the applications of lasers in restorative dentistry, including a comparison of the applications of lasers for major restorative dental procedures and conventional clinical approaches. A remarkable increase in the use of lasers for dental application is expected in the near future.

An in vitro evaluation of the responses of human osteoblast-like SaOs-2 cells on SLA titanium surfaces irradiated by different powers of CO2 lasers

Bacterial biofilms have been identified as the primary etiological factor for the development and progression of peri-implantitis. Lasers have been shown to remove bacterial plaque from titanium surfaces effectively and can restore its biocompatibility without damaging these surfaces. Therefore, the aim of this study was to evaluate the responses (i.e., the cell viability and morphology) of human osteoblast-like SaOs-2 cells to sandblasted, large grit, and acid-etched (SLA) titanium surfaces irradiated by CO2 lasers at two different power outputs. A total of 24 SLA disks were randomly radiated by CO2 lasers at either 6 W (group 1, 12 disks) or 8 W (group 2, 12 disks). Non-irradiated disks were used as a control group (four disks). The cell viability rates of the SaOs-2 cells in the control and study groups (6 and 8 W) were 0.33 ± 0.00, 0.24 ± 0.11, and 0.2372 ± 0.09, respectively (P < 0.6). Cells with cytoplasmic extensions and spreading morphology were most prominent in the control group (141.00 ± 29.00), while in the study groups (6 and 8 W), the number of cells with such morphology was 60.40 ± 26.00 and 35.20 ± 5.40, respectively (P < 0.005). Within the limits of this study, it may be concluded that the use of CO2 lasers with the aforementioned setting parameters could not be recommended for decontamination of SLA titanium surfaces.

Treatment of peri-implantitis and the failing implant

Appropriate treatment of implants is becoming increasingly important for the general dentist as the number of implants placed per year continues to increase. Early diagnosis of peri-implantitis is imperative; initiating the correct treatment protocol depends on a proper diagnosis. Several risk factors exist for the development of peri-implantitis, which can guide patient selection and treatment planning. Treatment of peri-implantitis should be tailored to the severity of the lesion (as outlined by the cumulative interceptive supportive treatment protocol), ranging from mechanical debridement to explantation. Several surgical and nonsurgical treatment alternatives exist. There is little consensus on superior treatment methods.

Decontamination of dental implant surface in peri-implantitis treatment: a literature review

Etiological treatment of peri-implantitis aims to reduce the bacterial load within the peri-implant pocket and decontaminate the implant surface in order to promote osseointegration. The aim of this literature review was to evaluate the efficacy of different methods of implant surface decontamination. A search was conducted using the PubMed (Medline) database, which identified 36 articles including in vivo and in vitro studies, and reviews of different decontamination systems (chemical, mechanical, laser and photodynamic therapies). There is sufficient consensus that, for the treatment of peri-implant infections, the mechanical removal of biofilm from the implant surface should be supplemented by chemical decontamination with surgical access. However, more long-term research is needed to confirm this and to establish treatment protocols responding to different implant characterics.