Erbium, Chromium:Yttrium-Scandium-Gallium-Garnet Laser Effectively Ablates Single-Species Biofilms on Titanium Disks Without Detectable Surface Damage

The Effects of Dental Hygiene Instruments on Streptococcus sanguinis Adhesion to Titanium Implant Abutments

INTRODUCTION

Maintenance of dental implant with different hygiene methods or instruments may cause a surface alteration. It directly affects bacterial colonization and adhesion on titanium implant surfaces that result in peri-implant diseases. This study aimed to compare the Streptococcus sanguinis (S. sanguinis) adhesion on titanium implant abutments after instrumentation with a rubber cup with pumice and erbium, chromium-doped: yttrium, scandium, gallium, and garnet (Er, Cr: YSGG) laser using scanning electron microscope (SEM) observation and colony-forming unit (CFU) measurement.

METHODS

Twenty-one MegaGen titanium implant abutments were randomly distributed into three groups. Seven abutments were respectively selected for the control/untreated (C) group, while the other two groups were treated with rubber cups with pumice (P) and Er, Cr: YSGG laser (L). All samples were cultured with S. sanguinis for bacterial colonization and adhesion. One sample for each group was selected for SEM observation, while the other samples were prepared for CFU calculation.

RESULTS

For SEM results, at 2,000× magnification, machining marks were intact in the C group, roughened in the L group, and smoothened in the P group. At 5,000× and 10,000× magnifications, moderate colonies of S. sanguinis were revealed in C and L groups, while sparse bacterial colonies were detected in the P group. However, for CFU results, statistical analysis showed no significant value (p>0.05) comparing all three groups.

CONCLUSION

P instrumentation revealed a lesser amount of S. sanguinis adhesion in SEM photographs, but no statistical significance of CFU results was noted for all three groups.

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.

Clinical, Bacterial, and Prosthodontic Parameters After Implant Abutment Disinfection Using Nd:YAG, Er,Cr:YSGG, Chlorhexidine, and Conventional Steam Before Prosthesis Delivery

Objective: This 1-year prospective clinical trial was designed to assess the microbial, clinical, radiographic, and prosthetic parameters after disinfection of the implant abutment connection using Er,Cr:YSGG (erbium, chromium-doped: yttrium, scandium, gallium, and garnet) and Nd:YAG (neodymium-doped yttrium, aluminum, garnet). Materials and methods: All the patients were divided into four groups; Group I: Nd:YAG laser, Group II: Er,Cr:YSGG laser, Group III: 0.2% chlorhexidine (CHx), and Group IV: steam disinfection. Peri-implant parameters assessed included peri-implant bleeding scores (PIBS), peri-implant plaque scores (PIPS), peri-implant pocket depth (PIPD), and crestal bone loss (CBL). The peri-implant plaque samples were acquired to perform microbiological analysis to assess Porphyromonas gingivalis, Treponema denticola, and Tannerella forsythia, respectively. All measurements were completed at baseline, 6 months, and 12 months postsurgery. Multiple groups were compared with the help of the Bonferroni post-hoc adjustment test (p < 0.01). Logistic regression models were utilized to assess the association between age, oral hygiene practices (brushing and flossing), and duration of implant function. Results: At the baseline level, there were no discernible differences in the peri-implant parameters between the study groups (p > 0.05). At the 6-month (p < 0.01) and 12-month (p < 0.001) follow-ups, all four study groups demonstrated a significant improvement in PIPS and PIBS, with no significant differences between the groups at baseline (p > 0.05). Based on an intergroup comparison, Group I (Nd:YAG) showed a significant decrease in PIBS when compared with the other groups. Group II showed a considerable decrease in PIPD and enhancements in CBL when compared with Groups I, III, and IV (p < 0.01). At the 6- and 12-month follow-up periods, P. gingivalis and T. denticola reduction were found to be statistically higher in Group II, whereas P. gingivalis and T. forsythia mean log CFU/mL were found to be statistically higher in Group I. Conclusions: Nd:YAG and Er,Cr:YSGG lasers both outperformed CHx and steam disinfection in terms of clinical, peri-implant, and prosthetic results when used to clean implant abutments.

The Effect of an Er, Cr: YSGG Laser Combined with Implantoplasty Treatment on Implant Surface Roughness and Morphologic Analysis: A Pilot In Vitro Study

Although laser irradiation and implantoplasty (IP) are both treatment options for peri-implantitis, no studies have yet combined these two treatment solutions. The aim of this study was to identify the effect of an Er, Cr: YSGG laser on the IP surface. In experiment 1, TiUnite anodized surface implants were treated with an Er, Cr: YSGG laser at 0.5 to 2 W on the panel energy setting and 20 Hz under water irrigation. In experiment 2, all implant surfaces were treated with the IP procedure first, then irradiated with the Er, Cr: YSGG laser. All samples were analyzed by stereomicroscopy, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and surface topography. Stereomicroscopy and SEM revealed no obvious surface change at any energy setting once the surface was polished with the IP procedure, whereas damage was caused to the TiUnite original implant surface when the Er, Cr: YSGG laser panel energy was set at 1 W or higher. EDS showed no significant difference in element composition once the surface was polished with the IP procedure, while a compositional change was detected when the Er, Cr: YSGG laser panel energy was set to 0.5 W or higher to irradiate the original TiUnite surface. Surface roughness may be related to laser irradiation energy, but no significant changes occurred following IP. These results indicated that the Er, Cr: YSGG laser may have little effect on the post-IP surface compared with the virgin TiUnite surface.

The effect of Er,Cr:YSGG laser on periodontopathic bacteria elimination: an in vitro study

In vitro bacterial elimination using the erbium, chromium: yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser against periodontopathic bacteria was investigated. Bacterial suspensions of Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis were spread on agar plates and the Er,Cr:YSGG laser was applied at 40 mJ pulse energy for durations of 30 s, 60 s, and 90 s. The agar plates were incubated, and growth inhibition zones were assessed. Optimal laser irradiation durations to achieve maximal bacterial elimination were evaluated using laser ablation on the bacterial colonies. The remaining viable bacteria were determined by the colony-forming unit (CFU) counting method. Growth inhibition zones were observed at all irradiation durations for both A. actinomycetemcomitans and P. gingivalis. Mean logarithmic values of CFU/ml after bacterial colony irradiation for 0 s (control), 12 s × 1 lap, 24 s × 1 lap, 48 s × 1 lap, and 24 s × 2 laps were 8.82 ± 0.35, 7.31 ± 0.94, 6.32 ± 0.61, 3.17 ± 2.90, and 0.00, respectively, for A. actinomycetemcomitans and 9.83 ± 0.50, 9.42 ± 0.11, 6.90 ± 1.60, 2.33 ± 3.19, and 0.00 for P. gingivalis. Significant differences were found between the control group and the two irradiated groups 48 s × 1 lap and 24 s × 2 laps (p < 0.05), and also between irradiated groups 12 s × 1 lap and 24 s × 2 laps (p < 0.05). An Er,Cr:YSGG laser with power setting 1.5 W and 30 Hz frequency showed potential for bacterial elimination against A. actinomycetemcomitans and P. gingivalis in vitro. Significant bacterial elimination (> 99.99%) was observed after 48 s of irradiation.

Physicochemical Changes of Contaminated Titanium Discs Treated With Erbium-Doped Yttrium Aluminum Garnet (Er:YAG) Laser Irradiation or Air-Flow Abrasion: An In Vitro Study

Introduction: Peri-implantitis is a common complication of dental implant treatment. A cause-and-effect relationship has been previously documented between microbial plaque and peri-implantitis and implant failure. A difference has been reported in the disinfection efficacy of erbium laser irradiation and air-flow abrasion for contaminated titanium surfaces. Also, the surface changes caused by lasers and air-flow abrasion have not been well studied. Thus, the purpose of this study was to compare the surface changes of contaminated titanium discs following decontamination by erbium-doped yttrium aluminum garnet (Er:YAG) laser irradiation and air-flow abrasion. Methods: Twenty-eight intact, sandblasted, and acid-etched (SLA) titanium discs were used. Twenty-four titanium discs were contaminated with Escherichia coli. Then, they were decontaminated by using Er:YAG laser irradiation and air-flow abrasion. Four discs remained intact. The mean and standard deviation of the contact angle and the weight percentage of aluminum, titanium, oxygen, carbon, phosphorus, and calcium were measured. Qualitative changes in surface topography of titanium discs were assessed by scanning electron microscopy (SEM). Results: The mean weight percentage of carbon in the air-flow abrasion group (4.98%) experienced a significant reduction compared with the contaminated (positive control) group (P=0.035). The contact angles were 46.54° and 38.67° in the laser and air-flow abrasion groups respectively, which were significantly lower than the value in the positive control group (75.15°) (P ≤0.001). SEM micrographs showed no significant change in the surface area in either technique. Conclusion: Air-flow abrasion was more successful in improving the surface characteristics of titanium discs with no alteration in surface topography or elements, compared with Er:YAG laser irradiation. Further studies regarding the safety of the Er:YAG laser for the decontamination of titanium surfaces are recommended.

Microbial Biofilm Decontamination on Dental Implant Surfaces: A Mini Review

Introduction

After insertion into the bone, implants osseointegrate, which is required for their long-term success. However, inflammation and infection around the implants may lead to implant failure leading to peri-implantitis and loss of supporting bone, which may eventually lead to failure of implant. Surface chemistry of the implant and lack of cleanliness on the part of the patient are related to peri-implantitis. The only way to get rid of this infection is decontamination of dental implants.

Objective

This systematic review intended to study decontamination of microbial biofilm methods on titanium implant surfaces used in dentistry.

Methods

The electronic databases Springer Link, Science Direct, and PubMed were explored from their inception until December 2020 to identify relevant studies. Studies included had to evaluate the efficiency of new strategies either to prevent formation of biofilm or to treat matured biofilm on dental implant surfaces.

Results and Discussion

In this systematic review, 17 different groups of decontamination methods were summarized from 116 studies. The decontamination methods included coating materials, mechanical cleaning, laser treatment, photodynamic therapy, air polishing, anodizing treatment, radiation, sonication, thermal treatment, ultrasound treatment, chemical treatment, electrochemical treatment, antimicrobial drugs, argon treatment, and probiotics.

Conclusion

The findings suggest that most of the decontamination methods were effective in preventing the formation of biofilm and in decontaminating established biofilm on dental implants. This narrative review provides a summary of methods for future research in the development of new dental implants and decontamination techniques.

Erbium, chromium-doped: yttrium, scandium, gallium, garnet and diode lasers in the treatment of peri-implantitis: clinical and biochemical outcomes in a randomized-controlled clinical trial

This study aims to evaluate the effects of 940 nm diode laser and 2780 nm erbium, chromium-doped: yttrium, scandium, gallium, garnet (Er,Cr:YSGG) laser used in addition to mechanical therapy in the non-surgical treatment of peri-implantitis on clinical parameters and matrix metalloproteinase-9 (MMP-9) and tissue inhibitor of metalloproteinase-1 (TIMP-1) levels in the peri-implant crevicular fluid. A total of 50 patients with peri-implantitis were randomized into three groups to receive peri-implant treatment. The control group (n = 17) only received conventional non-surgical mechanical therapy. The trial groups [(diode group (n = 16) and Er,Cr:YSGG group (n = 17)] received dental laser in addition to mechanical therapy. Gingival index (GI), plaque index (PI), bleeding on probing, probing depth (PD), MMP-9, and TIMP-1 levels were assessed at baseline (T0) and at 6 months after treatment (T1). The GI, PI, and PD significantly decreased in all groups at T1, compared to T0 (p < 0.05). The decrease in the PD was similar between the control and diode groups with Er,Cr:YSGG providing more reduction (1.16 ± 0.64 mm) than either method (p = 0.032). A significant intra-group decrease in MMP-9 level was only observed in the Er,Cr:YSGG group (p = 0.009). The decrease in TIMP-1 level from T0 to T1 was similar between the control and the diode groups (p > 0.05) and it was significantly lower than the decrease in the Er,Cr:YSGG group (p < 0.05). Addition of diode laser to non-surgical mechanical therapy does not provide any additional benefit for treatment outcomes. The Er,Cr:YSGG laser seems to be more efficient both at clinical and molecular levels. ClinicalTrials, ID: NCT04730687. Registered 13 April 2021. Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT04730687.

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%).

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.

Residual decontamination chemical agents negatively affect adhesion and proliferation of osteoblast-like cells on implant surface

Purpose

To investigate the influence of implant surface decontaminated and uncontaminated on osteoblast-like cell adhesion and proliferation

Materials and methods

Commercially available implants of different brands and surface characteristics were selected: Biomet 3i® Nanotite (NT) and Osseotite (OT), Straumann® SLActive (SLA), and Neodent® Acqua Drive (ACQ) and Neoporos Drive CM (CM). Physical and chemical properties of the implants were investigated by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and wettability analysis (WETT). Implants were previously contaminated with Aggregatibacter actinomycetemcomitans strains; after that, samples were decontaminated by different chemical methods. Decontaminated (test group; n = 15/type of implant) and uncontaminated (control group; n = 5/type of implant) samples were analyzed according to the number of human osteoblastic osteosarcoma cells (Saos-2) adhered on the implant surface after 24 h and 72 h in SEM images.

Results

ACQ was found to be highly hydrophilic, and NT was the most hydrophobic implant. Increased variation of Saos-2 cell adhesion and proliferation were observed on all test and control groups. Controversially, at the proliferation analysis in 72 h, CM implant was the only implant that showed no significant difference between test and group (p = 0.2833; Tukey’s multiple comparisons test). NT implants showed the greater value of cell proliferation when compared with all types of implant surface (p = 0.0002; Tukey’s multiple comparisons test).

Conclusions

These findings suggest that decontaminated surfaces were able to impair the counting of osteoblast-like cell adhesion and proliferation.

Dental implant surface temperatures following double wavelength (2780/940 nm) laser irradiation in vitro

Objective

To estimate the implant surface temperature at titanium dental implants during calibrated irradiation using double wavelength laser.

Material and methods

A double wavelength laser, 2780 nm Er,Cr:YSGG and 940 nm diode, was calibrated and used to irradiate pristine titanium dental implants, OsseoSpeed, TiUnite and Roxolid SLActive, representing different surface modifications. Initial calibration (21 implants; 7 implants/group) intended to identify optimal wavelength/specific output power/energy that not critically increased the temperature or altered the micro‐texture of the implant surface. Subsequent experimental study (30 implants; 10 implants/group) evaluated implant surface temperature changes over 190 s. Irradiation using a computerized robotic setup.

Results

Based on the initial calibration, the following output powers/energies were employed: Er,Cr:YSGG laser 18.4 mJ/pulse (7.3 J/cm²)–36.2 mJ/pulse (14.4 J/cm²) depending on implant surface; diode laser 3.3 W (1321.0 W/cm²). During double wavelength irradiation, implant surface temperatures dropped over the first 20 s from baseline 37°C to mean temperatures ranging between 25.7 and 26.3°C. Differences in mean temperatures between OsseoSpeed and TiUnite implants were statistically significant (p < 0.001). After the initial 20 s, mean temperatures continued to decrease for all implant surfaces. The decrease was significantly greater for TiUnite and Roxolid SLActive compared with OsseoSpeed implants (p < 0.001).

Conclusion

Calibrated double wavelength laser irradiation did not critically influence the implant surface temperature. During laser irradiation the temperature decreased rapidly to steady‐state levels, close to the water/air‐spray temperature.

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

OBJECTIVE

Implant surface decontamination is a challenging procedure for therapy of peri-implant disease. This study aimed to compare the effectiveness of decontamination on oral biofilm-contaminated titanium surfaces in Er:YAG laser, Er, Cr:YSGG laser, and plastic curette.

METHODOLOGY

For oral biofilms formation, six participants wore an acrylic splint with eight titanium discs in the maxillary arch for 72 hours. A total of 48 contaminated discs were distributed among four groups: untreated control; decontamination with plastic curettes; Er, Cr:YSGG laser; and Er:YAG laser irradiation. Complete plaque removal was estimated using naked-eye and the time taken was recorded; the residual plaque area was measured and the morphological alteration of the specimen surface was observed by scanning electron microscopy. The total bacterial load and the viability of adherent bacteria were quantified by live or dead cell labeling with fluorescence microscopy.

RESULTS

The mean treatment time significantly decreased based on the treatment used in the following order: Er:YAG, Er, Cr:YSGG laser, and plastic curettes (234.9±25.4 sec, 156.1±12.7 sec, and 126.4±18.6 sec, P=0.000). The mean RPA in the Er, Cr:YSGG laser group (7.0±2.5%) was lower than Er:YAG and plastic curettes groups (10.3±2.4%, 12.3±3.6%, p=0.023). The viable bacteria on the titanium surface after Er, Cr:YSGG laser irradiation was significantly lower compared to the decontamination with plastic curette (P=0.05) but it was not significantly different from the Er:YAG laser irradiation.

CONCLUSION

We found that Er:YAG laser and Er, Cr:YSGG laser irradiation were effective methods for decontaminations without surface alterations.

The influence of implant surface roughness on decontamination by antimicrobial photodynamic therapy and chemical agents: A preliminary study in vitro

BACKGROUND

The aim of this preliminary study was to analyze the effectiveness of three different protocols of decontamination on five commercial moderate rough implants.

MATERIAL AND METHODS

The types of implants investigated were: Neoporos Drive CM (CM; Neodent®), Drive CM Acqua (ACQ; Neodent®), SLActive (SLA; Straumann®), Osseotite (OT; Biomet 3i®) and Nanotite (NT; Biomet 3i®). Implant surface properties (n = 2/type of implant; control groups) were analyzed by scanning electron microscopy (SEM) images to determine surface roughness parameters (SRP) and energy disperse X-ray spectrometry to determine the chemical composition. Implants were then inoculated with Aggregatibacter actinomycetencomitans in vitro (n = 6/type of implant;experimental groups) and the contaminated areas were determined in SEM images (500x magnifications). Decontamination of implants was performed in duplicate by three protocols: antimicrobial photodynamic therapy (aPDT), EDTA associated with citric acid (EDTA + CA) and 0.12 % chlorhexidine (CHX). The remaining contaminated area (rCtA) was determined in SEM images (500x magnifications). All quantitative analysis through SEM images were analyzed in ImageJ® software for two-dimensional parameters.

RESULTS

No significant differences were found in SRP among implants (control group), except for Rv (lowest valley) between SLA vs. OT (p=0.0031; Kruskal Wallis post hoc Dunn). NT implants showed highest contaminated area vs. ACQ implants (68.19 % ± 8.63 % and 57.32 % ± 5.38 %, respectively; p = 0.0016, Tukey's test). SRP after decontamination showed statistical difference for Ra (arithmetical mean deviation) for all decontamination groups when compared to control (p < 0.05; ANOVA with post-hoc Tukey's multiple comparisons test), only CM implants showed statistical difference when compared decontamination protocols to control with highest modification of SRP for EDTA + AC group. For decontamination analysis, for applicability of different protocols in the same type of implant, only SLA showed statistical significant difference for aPDT vs. EDTA + CA (p = 0.0114; ANOVA with post-hoc Tukey's multiple comparisons test) with lowest rCTA for aPDT, however for ACQ implants the aPDT showed lowest rCTA with no statistical difference (p > 0.05; ANOVA with post-hoc Tukey's multiple comparisons test). No statistical difference was observed between the decontamination protocols at other implant types.

CONCLUSION

It can be suggested that the chemical-physical characteristics of dental implants can be effected by the process of contamination and decontamination by aPDT and chemical agents.

Er,Cr:YSGG laser surface treatment of gamma titanium aluminide: Scanning electron microscopy-energy-dispersive X-ray spectrometer analysis, wettability and Eikenella corrodens and Aggregatibacter actinomycetemcomitans bacteria count-in vitro study

Dental implants play an important role in oral health. Titanium dental implants must endure the complex microflora environment of the oral cavity. Moreover, bacterial infections have been considered as one of the most important factors of implant failure. The issue of dental improvement through modification of chemical composition and surface treatment has received considerable critical attention. γ-TiAl as a novo biocompatible material revealed a slower corrosion rate in biological media rather Ti-6Al-4V. The objective of this study is to investigate the effect of Er,Cr:YSGG laser on γ-TiAl in comparison with sandblasted and acid-etched samples as the control groups and machined samples.Wettability, surface roughness, surface topography, scanning electron microscopy-energy dispersive X-ray spectrometer analysis of surface and subsurface of samples were investigated and bacteria counts of two periodontal bacterial strains (Aggregatibacter actinomycetemcomitans and Eikenella corrodens) were evaluated on the Er,Cr:YSGG laser surface-treated sandblasted and acid-etched and machined samples.The results of this investigation show that Er,Cr:YSGG laser surface treatment affects surface roughness, surface topography, wettability, chemical composition of the surface and bacteria count. Scanning electron microscopy-energy dispersive X-ray spectrometer analysis of the sample revealed the increment of titanium and oxygen content and reduction of aluminum content in the surface and subsurface layer. A. actinomycetemcomitans and E. corrodens count were found from the lowest level to highest in the sandblasted and acid-etched samples, laser samples and machined samples, respectively.Using controlled parameters of Er,Cr:YSGG laser ensured no significant adverse alteration. The findings to emerge from this study revealed the significant correlation between microbial count and wettability. Furthermore, the contact angle strongly correlated with surface roughness.

The Effect of Er,Cr:YSGG and Diode Laser Applications on Dental Implant Surfaces Contaminated with Acinetobacter Baumannii and Pseudomonas Aeruginosa

Treatment of peri-implantitis through several implant surface decontamination techniques have been reported, however, some of them can negatively alter the implant surface or enhance more bacterial resistance. The aim of this in vitro study was to evaluate implant surface decontamination by means of Er,Cr:YSGG and diode lasers. Fifty micro-textured (MTX) dental implants were contaminated with Acinetobacter baumannii (n = 25) and with Pseudomonas aeruginosa (n = 25). All implants were then divided into five groups for the decontamination procedure. In group I (GI), decontamination was done with an Er,Cr:YSGG laser (2780 nm), while in group II (GII) decontamination was performed using photodynamic therapy (a 650 nm diode laser). In Group III (GIII) decontamination was performed with photodynamic therapy (an 808 nm diode laser), and in group IV (GIV) decontamination was performed with 0.12% chlorhexidine. Group V (GV) was the control group with no decontamination. After decontamination, colony forming units (CFU) were counted and implants were prepared for SEM analysis. A significant difference (p < 0.001) was observed for GI compared to the other groups, and also for GIV compared to both GII and GIII. The Er,Cr:YSGG laser (GI) showed the best results in decontaminating the implant surface. Chlorhexidine (GIV), proved to be better in decontaminating the implant surface than photodynamic therapy GII and diode laser GIII. No significant difference was found between group GII and GIII. The SEM analysis showed no significant change in the implant surface topography. The results of this study suggest that the Er,Cr:YSGG laser can be considered as an effective technique for reducing bacteria contamination on implant surfaces.