Laser reduction of specific microorganisms in the periodontal pocket using Er:YAG and Nd:YAG lasers: a randomized controlled clinical study

Biofilm removal from Difficult-to-Reach places via secondary cavitation within a constrained geometry mimicking a Periodontal/Peri-Implant pocket

Biofilm removal from the apical region of the periodontal or peri-implant pocket, which is very difficult to achieve with mechanical instruments, is a major unresolved issue in dentistry. Here, we propose the use of photoacoustically induced streaming and secondary cavitation to achieve superior cleaning efficacy in the apical region of the periodontal and peri-implant pocket. We have used a prefabricated narrow wedge system that mimics the consistency of periodontal and peri-implant pockets of both healthy and severely inflamed tissue. We studied the effect of single-pulse modality Er:YAG on Pseudomonas aeruginosa biofilm removal. We used different laser energies, fiber-tip positions, and laser treatment durations. The cleaning process was monitored in real-time with a high-speed camera after each individual laser pulse application. The obtained results suggest that biofilm cleaning efficacy in a difficult-to-reach place in healthy model tissue is directly related to the onset of secondary cavitation bubble formation, which correlates with a significant improvement of biofilm removal from the apical region of the periodontal or peri-implant pocket. In comparison to the healthy tissue model, the laser energy in inflamed tissue model had to be increased to obtain comparable biofilm cleaning efficacy. The advantage of photoacoustic cavitation compared to other methods is that laser-induced cavitation can trigger secondary cavitation at large distances from the point of laser application, which in principle allows biofilm removal at distant locations not reachable with a laser fiber tip or other mechanical instruments.

Efficacy of scaling and root planing with and without adjunct Nd:YAG laser therapy on glucose control and periodontal microecological imbalance in periodontitis patients with type 2 diabetes mellitus: a randomized controlled trial

OBJECTIVE

The study aims to determine the effects of Nd:YAG laser-assisted with subgingival scaling and root planing (SRP) treatment on glucose control and the dynamic changes of subgingival microbiome in periodontitis with type 2 diabetes mellitus (T2DM).

MATERIALS AND METHODS

Twenty-two patients were split into Nd:YAG group (n = 11) and SRP group (n = 11). Patients in the Nd:YAG group received SRP and auxiliary Nd:YAG laser treatment; patients in the SRP group received SRP treatment only. Periodontal tissue inflammation and glycemic control were assessed and analyzed during the treatment period and the changes of subgingival microbiome were analyzed by full-length 16S rRNA sequencing.

RESULTS

After 3 months of treatment, PD and CAL values improved significantly in the Nd:YAG group compared to the SRP group. BOP in both groups improved significantly after treatment. FPG levels in the Nd:YAG group were significantly reduced after treatment. Porphyromonas and Porphyromonadaceae were enriched in the Nd:YAG group at baseline, and Fusobacteriota, Fusobacteriia, Fusobacteriales, Leptotrichiaceae, and Leptotrichia were enriched after treatment.

CONCLUSION

Nd:YAG laser-assisted SRP therapy has additional benefits in improving periodontal tissue inflammation and blood glucose control in periodontitis patients with T2DM compared with SRP therapy alone and there was a trend towards a decrease in disease-associated taxa and an increase in health-associated taxa following auxiliary Nd:YAG laser treatment.

CLINICAL RELEVANCE

The effects of Nd:YAG laser-assisted SRP treatment on inflammation, glucose control, and subgingival microbiome in periodontitis patients with T2DM were elucidated, and new ideas for the treatment of T2DM periodontitis were provided.

Systemic inflammatory markers following adjunctive Nd:YAG (1064 nm) laser irradiation to step 2 of periodontal therapy: a 12-month, randomized, controlled trial

OBJECTIVES

The aim of this study was to investigate whether the use of adjunctive Nd:YAG (1064 nm) laser irradiation to full-mouth scaling and root planing (FM-SRP) may offer additional benefit in the systemic inflammatory status of the patient, as depicted in a variety of systemic biomarkers over FM-SRP alone, up to 12 months after treatment.

MATERIALS AND METHODS

A total of 60 otherwise healthy stage III/IV periodontal patients were equally distributed in 3 groups. The control group received FM-SRP. In laser A group, 1 week after FM-SRP, Nd:YAG laser irradiation was delivered in periodontal pockets with PD ≥ 4 mm using specific settings (3 W, 150 mJ, 20 Hz, 100 μs). In laser B group Nd:YAG laser irradiation was delivered twice, 1 week after FM-SRP and 1 week later with different settings compared to laser A (2 W, 200 mJ, 10 Hz, 100 μs).

RESULTS

A significant reduction (p = 0.038) of IL-1β serum levels at the 6-month time point was observed for laser A group. IL-6 was found statistically significantly increased (p = 0.011) in the control group at the 6-week time point, whereas no difference was reported for the laser-treated groups (laser A, laser B).

CONCLUSIONS

The adjunctive use of Nd:YAG laser irradiation, prevented from IL-6 increase after FM-SRP, 6 weeks after treatment. Similarly, Nd:YAG laser irradiation (3 W, 150 mJ, 20 Hz,100 μs) was associated with significantly lower IL-1β levels, 6 months post-operatively.

CLINICAL RELEVANCE

Additional Nd:YAG laser application to FM-SRP may provide a potential beneficial effect on systemic inflammation.

TRIAL REGISTRATION NUMBER

ISRCTN26692900.

REGISTRATION DATE

09/06/2022.

Distribution and influencing factors on residual pockets of the teeth in patients with periodontitis following non-surgical periodontal treatment: a retrospective observational study

BACKGROUND

Periodontitis is a chronic and multi-factorial infectious disease. A notable difference exists in the prognosis of patients with severe periodontitis after non-surgical periodontal treatment. Thus, a retrospective study was conducted to identify common and specific factors that impact the prognosis of patients with periodontitis stage III-IV following non-surgical periodontal treatment at different tooth sites.

METHODS

A total of 977 teeth were included in the study, comprising 266 patients diagnosed with periodontitis stage III-IV. This sample included 330 anterior teeth, 362 maxillary posterior teeth, and 285 mandibular posterior teeth. Following treatment, the teeth were categorized into two groups based on residual pocket depth [probing depth (PD) ≥ 5 mm] at 3 months post-treatment. The prognosis of periodontitis stage III-IV was assessed through multivariate analysis employing logistic regression to determine the association of various risk factors.

RESULTS

The PD values of each site and the deepest PD values of each tooth significantly decreased at 3 months post-treatment. Residual pockets were predominantly found in the mesio/disto-buccal and mesio/disto-lingual regions. Multivariate analysis revealed that gender, PD, sulcus bleeding index (SBI) and plaque index (PLI) at baseline, and crown-root ratio in anterior teeth had a significant influence on periodontitis stage III-IV (P < 0.05). Smoking, PD, PLI and furcation involvement (FI) at baseline, PLI at 3 months post-treatment, grades of periodontitis, and crown-root ratio were prediction factors for maxillary posterior teeth. Factors such as PD, PLI and FI at baseline, PLI at 3 months post-treatment, and crown-root were significant in mandibular posterior teeth.

CONCLUSIONS

The outcome of non-surgical treatment varies depending on the tooth positions for patients with periodontitis stage III-IV. Dentists must accurately identify the affected teeth that have periodontal pockets of more than 5 mm, taking into consideration the positions of the affected teeth, as well as various local and systemic factors. This comprehensive assessment will enable dentists to develop a customized and effective treatment plan.

Thermal Effects of 445-nm Diode Laser Irradiation on Titanium and Ceramic Implants

This study aimed to evaluate temperature changes in titanium and ceramic implants after using a 445-nm diode laser under different in vitro conditions. Titanium (Ti) and ceramic (Zr) dental implants were placed into a bone analog, and an intrabony defect was created at each implant. A 445-nm diode laser was used to irradiate the defects for 30 seconds, noncontact, at 2 W in continuous wave (c.w.) and pulsed mode. The experiment was done at room temperature (21.0 ± 1°C) and in a water bath (37.0 ± 1°C). Two thermocouple probes were used to record real-time temperature changes (°C) at the coronal part of the implant (Tc) and the apex (Ta). The temperature was recorded at time 0 (To) and after 30 seconds of irradiation (Tf). The average temperature change was calculated, and a descriptive analysis was conducted (P < .05). The Ti implant resulted in the highest ΔT values coronally (29.6°C) and apically (6.7°C) using continuous wave at 21°C. The Zr implant increased to 26.4°C coronally and 5.2°C apically. In the water bath, the coronal portion of the Ti and Zr implants rose to 14.2°C and 14.01°C, respectively, using continuous waves. The ΔT values for Ti were 11.9°C coronally and 1.7°C apically when placed in a water bath using pulsed mode. The lowest ΔT occurred on the Zr implant with ΔTc and ΔTa of 4.8°C and 0.78°C, respectively. Under in vitro conditions, the 445-nm diode laser in pulsed mode seems to be safe for use on ceramic implants and should be used with caution on titanium implants.

The Clinical and Microbiological Effects of LANAP Compared to Scaling and Root Planing Alone in the Management of Periodontal Conditions

The purpose of this study was to evaluate the efficiency of two therapeutic procedures clinically and microbiologically in the management of periodontally affected teeth: scaling and root planing alone and the laser-assisted new attachment procedure (LANAP). Molecular biological determinations of bacterial markers through the polymerase chain reaction (real-time PCR) method with standard PET tests (species-specific DNA probes at a time) were used for the quantification of three of the most important periodontal pathogens (Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, and Treponema denticola). Both nonsurgical periodontal therapies were proven effective in patients with chronic periodontal disease; however, LANAP was associated with a greater reduction in pocket depth and improved clinical outcomes, associated with a significant decrease in the amount of Porphyromonas gingivalis. The clinical results included a decrease in periodontal pocket depth, bleeding on probing, and dental plaque, with LANAP having better overall outcomes than SRP alone. The use of Nd:YAG lasers in LANAP therapy is a safe and effective procedure that is well accepted by patients.

Effectiveness of Diode Laser in Intraoral Soft Tissue Surgeries - An Evaluative Study

Introduction

The clinical application of the diode laser seems to have beneficial effects in surgery. The laser provides precise and rapid tissue dissection, excellent haemostasis and lessens post-operative inflammation. This study was done to assess the clinical effectiveness of diode laser in the management of different varieties of intraoral soft-tissue lesions.

Materials and Methods

After applying exclusion criteria, a total of 50 samples were selected with benign intraoral soft-tissue lesions treated with a diode laser under local anaesthesia between September 2017 and September 2020. Each patient was followed up on the 3rd, 7th and 15th post-operative days for healing, pain, infection and swelling.

Results

From all patients, a total of 50 were evaluated in the study; out of all, 60% of patients had no pain on the 2nd follow-up. As per the Landry Index of Healing, 54% of patients had excellent healing. None of the cases had post-operative bleeding, infection was present in 4% at the 1st-2nd follow-up, and in 2% of cases, post-operative swelling was present. The efficacy of diode lasers was tested using the Chi-square test and P < 0.01, which was statistically significant.

Discussion

Diode laser seems to be superior over conventional treatment modalities as it provides a bloodless dry field and increases patient comfort during surgery. It also lessens the post-operative pain and swelling. Diode laser can safely and effectively be used as a treatment modality for benign soft-tissue lesions, without any complication and without compromising the health and function of patients.

Adjunctive Nd:YAG laser irradiation in the treatment of stage III/IV periodontitis: a 12-month, randomized, controlled trial

OBJECTIVES

The aim of this study was to evaluate the clinical efficacy of the adjunctive use of Nd:YAG laser (1064 nm) to full-mouth scaling and root planning (FMS), in stage III/IV periodontitis patients.

MATERIALS AND METHODS

Sixty stage III/IV periodontitis patients were randomly assigned to three groups. The control group received FMS, laser 1 group received combined FMS/single Nd:YAG laser irradiation (3 W, 150 mJ, 20 Hz,100 μs), and laser 2 group received combined FMS/double Nd:YAG laser irradiation with 1-week interval (2.0 W, 200 mJ, 10 Hz, 100 μs). PD, CAL, FMPS, GI, FMBS, and GR were evaluated at baseline, 6 weeks, 3, 6, and 12 months after treatment. Patient-reported outcomes were evaluated 1 week after treatment.

RESULTS

A significant improvement (p < 0.001) for all clinical parameters was observed during the entire study period, with the exception of mean CAL gain for the laser 2 group at 12 months. The percentage of pockets ≤ 4 mm was significantly higher compared to baseline for all groups throughout the study, with no inter-group differences at any time point. Patient-reported analgesic consumption was higher for laser 1 group.

CONCLUSIONS

The adjunctive use of Nd:YAG laser irradiation was similarly effective to FMS alone, during the entire study period. A slightly higher, though not statistically significant improvement was reported for PD at 6 and 12 months after a single post-FMS application of Nd:YAG laser for pocket epithelium removal and coagulation.

CLINICAL RELEVANCE

Additional Nd:YAG laser application for sulcular epithelium removal and coagulation may provide minor long-term improvements compared to FMS or laser irradiation for pocket disinfection and detoxification.

TRIAL REGISTRATION

ISRCTN26692900. Registration date: 09/06/2022.

Novel Dental Restorative Solutions for Natural Teeth and Implants

The long-term survival of restorations in the oral cavity has always been one of the most significant challenges in modern dental practice [...].

Combination of Nd:YAG and Er:YAG lasers in non-surgical periodontal therapy: a systematic review of randomized clinical studies

Lasers are increasingly utilized in the non-surgical treatment of periodontal disease. The aim of the present systematic review with meta-analysis was to investigate the combination use of Nd:YAG and Er:YAG laser therapy in the treatment of severe periodontitis. A systematic review of the literature including searches in PubMed/Medline, Cochrane Library, Google Scholar, and Grey Literature databases, as well as manual searches, was performed until November 1, 2021. Only studies a combination of lasers during non-surgical treatment of pockets ≥ 6mm were included. The eligibility criteria for meta-analysis comprised randomized controlled trials (RCTs) comparing the use of combination laser therapy with/without adjunctive mechanical for the non-surgical management of periodontitis. From 57 initial articles, 6 full-text articles were assessed for eligibility. Two studies were excluded, one study was not a randomized clinical trial (case series), and one study was an in vitro study. Four RCTs were included in the meta-analysis. It was shown that combination of Nd:YAG and Er:YAG may be beneficial for non-surgical periodontal therapy with an additional average reduction in pocket depth and clinical attachment level reported at 1.01 and 0.77 mm respectively when compared to controls. The findings suggest that the combination of Nd:YAG and Er:YAG lasers may lead to additional clinical improvements compared to nonsurgical treatment alone. Future research is needed to substantiate these findings and optimize clinical guidelines including more specific laser protocols. Preliminary data suggest favorable outcomes following the combination of Nd:YAG and Er:YAG lasers for non-surgical periodontal therapy.

Disinfection Potential of 980 nm Diode Laser and Hydrogen Peroxide (3%) in "Critical Probing Depths" Periodontal Pockets: Retrospective Study

A successful treatment of periodontitis depends largely on the successful elimination of the periodontopathogens during non-surgical and surgical mechanical debridement. In this retrospective study, data collection was conducted from 2017 to 2021. The retrospective study included 128 patients with 128 sites of localized periodontitis with pocket depths > 5 mm. The included data were based on sites that received conventional mechanical debridement followed by different adjunctive approaches. In total, 30 patients did not receive any additional treatment (SRP group), 30 patients received SRP + 980 nm diode laser irradiation only (SRP + laser), 30 patients received SRP + 3% hydrogen peroxide irrigation (SRP + H2O2) only and 30 patients received a combined treatment of 3% hydrogen peroxide and 980 nm diode laser irradiation (SRP + H2O2 + laser). Total bacterial counts (TBC) in the periodontal pocket collected for all participants before treatment, immediately after treatment, 6 weeks after treatment, 12 weeks after treatment and 6 months after treatment were statistically analyzed and compared. When the laser was used, irradiation parameters were 10 μsec/pulse duration, 10 kHz, pick power of 10 W, average power of 1 W, irradiation time of one minute with inward and outward movements, and fiber diameter of 320 μm. The irradiation was repeated 3 times/pocket. When hydrogen peroxide was used, the irrigation was conducted for one minute and repeated 3 times. The maximum reduction in TBC was obtained when SRP was coupled with 3% H2O2 irrigation followed by 980 nm diode laser irradiation. After six months of follow-up, a significant reduction in TBC was obtained for the group of SRP + H2O2 + laser when compared to all the other groups, from 7.27 × 107 before intervention to 3.21 × 107 after six months. All three approaches to SRP showed a significant reduction in TBC immediately after treatment. Values were 3.52 × 107, 4.01 × 106, 9.58 × 106, 1.98 × 106 for SRP alone, SRP + diode, SRP + H2O2 and SRP + H2O2 + diode laser, respectively. At 6 months, we saw no significant difference between SRP + laser and SRP + H2O2 with 4.01 × 107 and 4.32 × 107, respectively. This retrospective study reveals that after SRP, irrigation with 3% hydrogen peroxide and irradiation with a 980 nm diode laser within specific treatment protocol can be used as an additional approach to conventional SRP to increase the disinfection of the periodontal pockets > 5 mm.

Probing depth reduction of laser application in periodontal therapy: a network meta-analysis

The aim was to systematically evaluate the probing depth (PD) reduction of lasers in scaling and root planing (SRP) of chronic periodontitis by network meta-analysis (NMA). Randomized controlled clinical trials (RCTs) were searched through electronic-search and hand-search up to January 2020. Standard mean different (SMD) and 95% confidence interval (CI) were counted for PD reduction. The random-effects NMA were performed using mvmeta routine in STATA software (version 13). This NMA analysed seven periodontal treatments through 37 RCTs. No inconsistency was detected. Compared with mechanical SRP, significant differences were in favour of diode laser (DL) as adjunct at 3 months (SMD = 0.61; 95% CI range: 0.27-0.96) and Nd:YAG as adjunct (SMD = 0.29; 95% CI range: 0.03-0.55), Er,Cr:YSGG as monotherapy (SMD = 0.37; 95% CI range: 0.04-0.71) and Er,Cr:YSGG as adjunct (SMD = 0.53; 95% CI range: 0.23-0.84) at 6 months after treatment. Compared with Er:YAG as monotherapy, significant differences were in favour of DL as adjunct at 6 months (SMD = 0.51; 95% CI range: 0.07-0.95) after treatment. In terms of PD reduction at 3-month follow-up, the ranking result from best to worst was Nd:YAG as adjunct, DL as adjunct, Er:YAG as adjunct, Er,Cr:YSGG as monotherapy, Er:YAG as monotherapy and mechanical SRP. In terms of PD reduction at 6-month follow-up, the ranking result was DL as adjunct, Nd:YAG as adjunct, Er:YAG as adjunct, Er,Cr:YSGG as adjunct, Er:YAG as monotherapy, Er,Cr:YSGG as monotherapy and mechanical SRP. Laser-assisted periodontal treatment has better PD reduction.

Erbium lasers in non-surgical periodontal therapy: an umbrella review and evidence gap map analysis

The literature on the efficacy of erbium lasers for nonsurgical periodontal therapy is inconsistent. The objective of the umbrella review was to collate the information available in the systematic reviews to provide a comprehensive synthesis of clinical and patient reported outcomes following the use of erbium lasers for non-surgical periodontal therapy. An electronic database search was carried out, and systematic reviews/meta-analyses which assessed the efficacy of erbium lasers as monotherapy or as an adjunct to scaling and root planing were included. The methodological quality and reporting quality of the included studies were assessed. 15 Systematic reviews/meta-analyses were obtained after title, abstract, and full text search. The meta-analyses data revealed a clinical attachment level gain, reduction in probing pocket depth at 1 and 3-month follow-up, and no additional benefit at ≥ 6-month follow-up in the erbium laser group. The evidence gap map revealed lack of clinical outcome data at > 6-month follow-up and dearth in studies assessing patient reported outcome measures and adverse events. Erbium lasers may provide short-term clinical benefits, and further studies with standardized laser parameters evaluating long-term follow-up, patient-reported outcome measures, and adverse events are needed.

Effect of Twinlight Laser on the Attachment of Human Gingival Fibroblasts to the Root Surface In Vitro

Background

This study aimed to compare the effectiveness of subgingival scaling and root planing with the Twinlight laser, Er: YAG laser, and hand instrumentation on the removal of endotoxin and attachment of human gingival fibroblasts (HGFs) to cementum surfaces in vitro.

Material/Methods

Single-rooted teeth extracted for periodontal disease were collected and divided into 3 groups: group A, root planing with Gracey curet no. 5/6; group B, irradiation with Er: YAG laser; group C, irradiation with Er: YAG laser and Nd: YAG laser. Endotoxins were determined by the limulus amebocyte lysate test. Cell attachment and proliferation of HGFs on root specimens were evaluated by cell counting kit-8 assay. The root surface and cell morphology were observed by scanning electron microscope.

Results

A flat root surface with scratches was found in group A, Group B had a homogeneous rough morphology without carbonization, and group C had a non-homogeneous rough morphology with ablation. The endotoxin concentration was highest in group A (P<0.05) and lowest in group C (P>0.05). HGFs cultured in group B showed significantly increased adhesion and proliferation compared with groups A and C (P<0.05). HGFs in group B were well attached, covered densely by pseudopodia. HGFs in group A were round with poor extension and short pseudopodia, while the cells in the group C were in narrow, triangular, or polygonal shapes.

Conclusions

Twinlight laser-assisted periodontal treatment effectively improved the biocompatibility of root surface and promoted the attachment and proliferation of fibroblasts by removing calculus and reducing the concentration of endotoxins.

LASER in periodontal treatment: is it an effective treatment or science fiction?

There are several studies that evaluate the use of lasers in periodontal treatment in non-surgical or surgical therapy. However, while several studies showed clinically beneficial effects of some lasers in periodontal treatment, there are few clinical reports of additional advantages of lasers as adjunctive treatments in periodontology. The aim of this paper is to demonstrate and critically analyze the level of scientific evidence of effects of low-level lasers and high-power lasers in periodontology. A narrative review of the studies was carried out in each topic and type of laser or periodontal treatment. In nonsurgical periodontal therapy the results showed that there is an additional clinical benefit when using a diode laser (DL) associated with scaling and root planing (SRP) in patients with moderate to severe periodontitis. The Er:YAG laser seems to be the most suitable for nonsurgical periodontal therapy and promotes the same clinical effects as conventional therapy. In periodontal surgery vaporization of the gingival or mucosal tissue can be carried out with DL, CO2, Nd:YAG, Er:YAG and Er,Cr:YSGG lasers. Photobiomodulation (PBM), mediated by low-level lasers associated with non-surgical periodontal therapy, promotes additional benefits in the short term and accelerates the bone and gingival tissue repair process and also reduces postoperative symptoms of periodontal surgery. The effect of antimicrobial Photodynamic Therapy is relevant in the initial reevaluation periods. Studies have shown controversial results of the use of lasers in periodontics, and this fact may be due to the lack of standard parameters of irradiation in each clinical application.

Erbium-doped: yttrium-aluminum-garnet (Er:YAG) versus scaling and root planing for the treatment of periodontal disease: A single-blinded split-mouth randomized clinical trial

BACKGROUND

This randomized, controlled clinical trial aimed to compare the differences in periodontal clinical outcomes, duration of the procedure, and patient's experience between conventional scaling and root planing and erbium-doped: yttrium-aluminum-garnet (Er:YAG) in the treatment of generalized moderate to severe chronic periodontitis or generalized Stages II or III, and Grade B periodontitis based on the Centers for Disease Control (CDC), American Academy of Periodontology (AAP), and European Federation of Periodontology (EFP) definitions.

METHODS

Thirty subjects were initially recruited. In a split-mouth fashion, right and left sides were randomly allocated into two treatment arms: conventional scaling and root planing (C-SRP) versus laser-assisted scaling and root planing (L-SRP). A blinded examiner recorded clinical measurements at baseline and 3 months. Duration of the procedure was also recorded for each visit, and the patient's experience was assessed with a questionnaire at baseline, 1, and 3 months.

RESULTS

The final sample consisted of 26 subjects. Both treatments resulted in overall improvement, but no significant differences were found between modalities for clinical attachment gain or probing depth reduction. The duration of the procedure was approximately half for L-SRP, and postoperative sensitivity was greater in C-SRP.

CONCLUSIONS

The low-energy protocol with Er:YAG (50 mJ) used for the non-surgical treatment of moderate-severe chronic or Stage II-III, Grade B periodontitis performed in this study population was a treatment modality that yielded similar clinical improvements when compared to conventional scaling and root planing.

Residual periodontal pocket treatment with Er:YAG laser-assisted comprehensive periodontal pocket therapy: a retrospective study

OBJECTIVES

Recently, the application of erbium-doped yttrium aluminum garnet (Er:YAG) laser has been increasing in periodontal therapy. In this retrospective study, we evaluated the safety and effectiveness of a novel pocket therapy using Er:YAG laser in combination with conventional mechanical scaling and root planing treatment (Er:YAG laser-assisted comprehensive periodontal pocket therapy).

METHODS

Forty sites in 29 elderly patients having residual periodontal pockets of ≥ 5 mm depth were treated by curette and Er:YAG laser from 2006 to 2009. After root debridement by curette, laser irradiation was performed on the root surfaces. Then, inflamed connective tissue on the inner gingival surface and on the bone surface/within extant bone defects was thoroughly debrided by curette and laser. Furthermore, in most cases, removal of the outer epithelium and coagulation of the blood clot in the pocket entrance were additionally performed with laser. Clinical parameters were evaluated before and 3, 6, and 12 months after treatment.

RESULTS

With Er:YAG laser-assisted pocket therapy, debridement of pockets was thoroughly and safely performed, and favorable clinical improvements were observed in most cases, without any adverse side effects and complications. After 1 year, probing pocket depth significantly decreased from 6.4 ± 1.4 to 3.5 ± 1.3 mm (p < 0.001, 3.0 mm reduction), and clinical attachment level significantly decreased from 7.5 ± 1.6 to 5.2 ± 1.9 mm (p < 0.001, 2.3 mm gain).

CONCLUSION

The results of this study indicate that Er:YAG laser-assisted therapy is useful for the treatment of residual pockets as a minimally invasive flapless surgery.

CLINICAL RELEVANCE

Er:YAG laser-assisted comprehensive pocket therapy reduces the necessity of more conventional surgical therapies.

Low-level laser irradiation enhances the proliferation and osteogenic differentiation of PDLSCs via BMP signaling

The aim of this in vitro study was to evaluate the effects of low-level laser therapy (LLLT) at different energy intensities on proliferation and osteogenesis of periodontal ligament stem cells (PDLSCs). We designed one control group, without irradiation and four testing groups, treated with LLLT (Nd:YAG;1064 nm) at 2, 4, 6, and 8 J/cm² for human PDLSCs. Cell proliferation was measured using colony-forming unit fibroblast assay and 3-(4,5-dimethylthiazol-2yl)-2,5-diphenyltetrazolium bromide assay. Osteogenic capacity of cells was determined by alkaline phosphatase (ALP) staining, ALP activity assay, Alizarin Red S staining, and the gene levels of runt-related transcription factor 2 (Runx2), ALP, osteocalcin, and bone morphogenetic protein 2 (BMP2). The effects of LLLT on secretion of TNF-α and IL-1β in PDLSCs were measured by enzyme-linked immunosorbent assay. BMP/Smad pathway was measured through the expression of Smad1/5/8 phosphorylation (P-Smad1/5/8). LDN-193189, an inhibitor of the BMP/Smad pathway, was used to explore the underlying effects of BMP/Smad signaling on the process of LLLT regulating the proliferation and osteogenesis of PDLSCs. Our results demonstrated LLLT could promote the proliferation and osteogenesis of PDLSCs at 2-6 J/cm² and LLLT at 8 J/cm² significantly suppress osteogenic differentiation of PDLSCs. Moreover, LLLT stimulated the secretion of TNFα and IL-β1. Finally, we found the irradiation positively modulates the P-Smad1/5/8 level. When the cells were treated with LDN-193189, the proliferation and osteogenic effects of LLLT on PDLSCs were attenuated. In conclusion, LLLT may upregulate the proliferation and bone formation ability of PDLSCs via the BMP/Smad signaling.

Efficacy of a combined Er:YAG laser and Nd:YAG laser in non-surgical treatment for severe periodontitis

Severe periodontitis is challenging to treat. The aim of this study was to evaluate the efficacy of a combined Er:YAG laser (ERL) and Nd:YAG laser (NDL) in non-surgical treatment for severe periodontitis. One week after supragingival scaling, 32 systemically healthy patients with stage III or IV periodontitis were randomly divided into a control group (16 subjects) and a test group (16 subjects). The control group was treated by scaling and root planning (SRP) with ultrasonic equipment and manual instruments, and the test group was treated by SRP as well as ERL and NDL. Before treatment, the following clinical parameters were recorded at baseline: debris index (DI), probing depth (PD), clinical attachment level (CAL), and percentage of bleeding on probing (BOP %). Two months after therapy, the clinical parameters were recorded again, and the results between the groups were compared. All clinical parameters were significantly improved in both groups after therapy. For moderately deep periodontal pockets (4 mm ≤ PD ≤ 6 mm), the gains in CAL were greater in the test group (1.17 ± 1.47 mm) than in the control group (0.46 ± 2.78 mm), while no significant difference was found for PD reductions after therapy between the two groups. For deep periodontal pockets (PD > 6 mm), the differences in all of the clinical parameters were similar between the test group and the control group. In this short-term study, ERL and NDL radiation exhibited potential advantages in improving the clinical attachment level compared to conventional SRP in the non-surgical treatment of severe periodontitis.

Short-term results of the combined application of neodymium-doped yttrium aluminum garnet (Nd:YAG) laser and erbium-doped yttrium aluminum garnet (Er:YAG) laser in the treatment of periodontal disease: a randomized controlled trial

Objectives

Nd:YAG and Er:YAG lasers have been previously used as an adjunct in periodontal therapy. The aim of this single-blinded randomized controlled clinical trial was to evaluate the efficacy of a combined application of Nd:YAG and Er:YAG laser irradiation in periodontal treatment.

Materials and methods

Twenty-two patients with at least one site of ≥ 6 mm periodontal probing depth (PPD) after mechanical debridement with curettes and sonic instruments at periodontal reevaluation were included in the study. Patients were randomly allocated at a 1:1 ratio to either a combined Nd:YAG/Er:YAG laser therapy (test group) or a “turned off” laser therapy (control group). The Nd:YAG laser was used for periodontal pocket deepithelialization and to stabilize the resulting blood clot. The Er:YAG laser was primarily used for root surface modification. PPD (mm), clinical attachment level (CAL, mm), and bleeding on probing (BOP, +/−) at the site of laser treatment were evaluated at baseline and 2 months after treatment.

Results

The mean improvements from baseline to 2-month follow-up for PPD were significantly better in the laser group (2.05 ± 0.82 mm) compared to the control group (0.64 ± 0.90 mm; p = 0.001). Likewise, the gain in CAL was significantly better in the laser group (1.50 ± 1.10 mm) than in the control group (0.55 ± 1.01mm; p = 0.046).

Conclusions

The combined application of Nd:YAG and Er:YAG laser irradiation as an adjunct to conventional non-surgical therapy showed a significant beneficial effect on periodontal treatment results.

Clinical relevance

Combined Nd:YAG and Er:YAG laser irradiation could be a useful procedure additionally to conventional non-surgical periodontal therapy to improve periodontal treatment results.

Clinical trial registration

ISRCTN registry #ISRCTN32132076

Adjunctive laser or antimicrobial photodynamic therapy to non-surgical mechanical instrumentation in patients with untreated periodontitis: A systematic review and meta-analysis

AIM

To compare the adjunctive effects of lasers or antimicrobial photodynamic therapy (aPDT) to non-surgical mechanical instrumentation alone in untreated periodontitis patients.

MATERIALS AND METHODS

Two focused questions were addressed using the Population, Intervention, Comparison and Outcome criteria as follows: in patients with untreated periodontitis, (a) does laser application provide adjunctive effects on probing pocket depth (PPD) changes compared with non-surgical instrumentation alone? and (b) does application of aPDT provide adjunctive effects on PPD changes compared with non-surgical instrumentation alone? Both randomized controlled clinical trials (RCTs) and controlled clinical trials (CCTs) were included. Results of the meta-analysis are expressed as weighted mean differences (WMD) and reported according to the PRISMA guidelines.

RESULTS

Out of 1,202 records, 10 articles for adjunctive laser and 8 for adjunctive aPDT were included. With respect to PPD changes, 1 meta-analysis including 2 articles (total n = 42; split-mouth design) failed to identify a statistically significant difference (WMD = 0.35 mm; 95%CI: -0.04/0.73; p = .08) in favour of adjunctive aPDT (wavelength range 650-700 nm). In terms of adjunctive laser application, a high variability of clinical outcomes at 6 months was noted. Two articles included patient-reported outcomes and 10 reported on the presence/absence of harms/adverse effects.

CONCLUSIONS

Available evidence on adjunctive therapy with lasers and aPDT is limited by (a) the low number of controlled studies and (b) the heterogeneity of study designs. Patient-reported benefits remain to be demonstrated.

The effect of post-extraction socket preservation laser treatment on bone density 4 months after extraction: Randomized controlled trial

Background

Post‐extraction bone resorption may affect the outcome of ensuing restorations.

Purpose

This study aimed to evaluate a comprehensive laser post‐extraction protocol by comparing resulting alveolar bone regeneration with that obtained after standard extraction procedure.

Materials and Methods

About 53 simple extractions were randomized to either laser or control group. In the laser group, erbium (Er:YAG; 2940 nm) and neodymium (Nd:YAG; 1064 nm) lasers were used for degranulation, disinfection, de‐epithelialization of the surrounding gingiva, clot stabilization, and photobiomodulation. The primary outcome measure was change in bone density in the extraction area between day 1 and 4 months after extraction. Patients were monitored for potential side effects.

Results

Increase in bone density at the follow‐up CBCT was significantly higher in laser than in control group (p < 0.001). No post‐operative pain, bleeding, or swelling was present in the laser group. In the control group, one patient had bleeding 3–5 days after extraction, two patients had swelling and three patients reported post‐operative pain rated 3–5 on a 0–10 pain scale up to 3 days after extraction.

Conclusions

The proposed laser post‐extraction procedure is a safe and effective method to improve post‐extraction bone healing.

Retrieval of Prefabricated Zirconia Crowns with Er,Cr:YSGG Laser from Primary and Permanent Molars

(1) Background: Prefabricated zirconia crowns are used to restore teeth in children. The purpose of this study was to evaluate the removal of these crowns with the erbium, chromium: yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser; (2) Methods: A total of 12 primary and 12 permanent teeth were prepared and prefabricated zirconia crowns were passively fitted and cemented with two resin modified glass-ionomer (RMGI) cements. Surface areas of prepared teeth and crowns were calculated. Crowns were removed using two laser settings: 4.5 Watts, 15 Hertz, 20 water/20 air, and 5 Watts, 15 Hertz, 50 water/50 air. The retrieval time and temperature changes were tested recorded. Data were analyzed using ANOVA with Tukey’s adjusted post hoc pairwise comparison t-test; (3) Results: The average time for crown removal was: 3 min, 47.7 s for permanent; and 2 min 5 s for primary teeth. The mean temperature changes were 2.48 °C (SD = 1.43) for permanent; and 3.14 °C (SD = 1.88) for primary teeth. The time to debond was significantly positively correlated with tooth inner surface area and volume, outer crown volume, and the cement volume; (4) Conclusions: Use of the Er,Cr:YSGG laser is an effective, safe and non-invasive method to remove prefabricated zirconia crowns cemented with RMGI cements from permanent and primary teeth.

Laser Treatment of Fiber Post and Final Push-Out Bond Strength: A Systematic Review and Meta-Analysis

Purpose: This review article tries to answer this question: "What are the effects of laser surface treatment of fiber posts (FPs), compared with other surface roughening methods, on bond strength of cemented FPs?" Methods: Search was carried out in six electronic databases by focusing on defined key words. Related titles and abstracts, up to March 2019, were collected, read, and selected for quality assessments. A total of 2408 articles were included in the study at the initial stage of the searching phase. Results: Finally, seven studies were recognized to be reliable to be reviewed and meta data analysis in the study. All the studies were in vitro with a total of 340 samples. None of the Er:YAG (-0.27, 95% CI: -2.29 to 1.76; p = 0.79) and Er,Cr:YSGG (-0.04, 95% CI: -1.43 to 1.35; p = 0.95) treated samples showed any significant overall mean differences in final push-out bond strength (PBS) compared with the control groups. Conclusions: Laser pretreatment of FP surfaces might not be effective in providing high PBS. FP surface are susceptible to damage of high-level laser irradiation and might show decreased bond strength.

Bio-Inspired Systems in Nonsurgical Periodontal Therapy to Reduce Contaminated Aerosol during COVID-19: A Comprehensive and Bibliometric Review

Background: On 30 January 2020, a public health emergency of international concern was declared as a result of the new COVID-19 disease, caused by the SARS-CoV-2 virus. This virus is transmitted by air and, therefore, clinical practices with the production of contaminant aerosols are highly at risk. The purpose of this review was to assess the effectiveness of bio-inspired systems, as adjuvants to nonsurgical periodontal therapy, in order to formulate bio-inspired protocols aimed at restoring optimal condition, reducing bacteremia and aerosols generation. Methods: A comprehensive and bibliometric review of articles published in English. Research of clinical trials (RCTs) were included with participants with chronic or aggressive periodontal disease, that have compared benefits for nonsurgical periodontal therapy (NSPT). Results: Seventy-four articles have been included. For probing depth (PPD) there was a statically significant improvement in laser, probiotic, chlorhexidine groups, such as gain in clinical attachment level (CAL). Bleeding on probing (BOP) reduction was statistically significant only for probiotic and chlorhexidine groups. There were changes in microbiological and immunological parameters. Conclusions: The use of bio-inspired systems in nonsurgical periodontal treatment may be useful in reducing risk of bacteremia and aerosol generation, improving clinical, microbiological and immunological parameters, of fundamental importance in a context of global pandemic, where the reduction of bacterial load in aerosols becomes a pivotal point of clinical practice, but other clinical trials are necessary to achieve statistical validity.

Dental Aerosol as a Hazard Risk for Dental Workers

Standard dental procedures, when using a water coolant and rotary instruments, generate aerosols with a significantly higher number of various dangerous pathogens (viruses, bacteria, and fungi). Reducing the amount of aerosols to a minimum is mandatory, especially during the new coronavirus disease, COVID-19. The study aimed to evaluate the amount of aerosol generated during standard dental procedures such as caries removal (using dental bur on a high and low-speed handpiece and Er:YAG laser), ultrasonic scaling, and tooth polishing (using silicon rubber on low-speed handpiece) combined with various suction systems. The airborne aerosols containing particles in a range of 0.3-10.0 μm were measured using the PC200 laser particle counter (Trotec GmbH, Schwerin, Germany) at three following sites, manikin, operator, and assistant mouth, respectively. The following suction systems were used to remove aerosols: saliva ejector, high volume evacuator, saliva ejector with extraoral vacuum, high volume evacuator with extraoral vacuum, Zirc® evacuator (Mr.Thirsty One-Step®), and two customized high volume evacuators (white and black). The study results showed that caries removal with a high-speed handpiece and saliva ejector generates the highest amount of spray particles at each measured site. The aerosol measurement at the manikin mouth showed the highest particle amount during caries removal with the low and high-speed handpiece. The results for the new high volume evacuator (black) and the Zirc® evacuator showed the lowest increase in aerosol level during caries removal with a high-speed handpiece. The Er:YAG laser used for caries removal produced the lowest aerosol amount at the manikin mouth level compared to conventional dental handpieces. Furthermore, ultrasonic scaling caused a minimal aerosol rise in terms of the caries removal with bur. The Er:YAG laser and the new wider high volume evacuators improved significantly suction efficiency during dental treatment. The use of new suction systems and the Er:YAG laser allows for the improvement of biological safety in the dental office, which is especially crucial during the COVID-19 pandemic.

Efficacy of laser monotherapy or non-surgical mechanical instrumentation in the management of untreated periodontitis patients. A systematic review and meta-analysis

Objective

To evaluate and compare the effects of laser monotherapy with non-surgical mechanical instrumentation alone in untreated periodontitis patients.

Materials and methods

A focused question was formulated based on the Population, Intervention, Comparison, Outcome, and Study design criteria (PICOS): in patients with untreated periodontitis, does laser mono-therapy provide adjunctive effects on pocket probing depth (PPD) changes compared with non-surgical instrumentation alone? Both randomized controlled clinical trials (RCTs) and controlled clinical trials (CCTs) were included. The results of the meta-analyses are expressed as weighted mean differences (WMD) and reported according to the PRISMA guidelines.

Results

The search yielded 1268 records, out of which 8 articles could be included. With respect to PPD changes, a meta-analysis including 5 articles (n = 148) failed to identify statistically significant differences in favor of laser monotherapy for PPD change (WMD = 0.14 mm; 95% CI: − 0.04/0.32; z = 1.51; p = 0.132) nor for clinical attachment level (CAL) (WMD = 0.04 mm; 95% CI: − 0.35/0.42; z = 0.19; p = 0.850). Data on cost-effectiveness are lacking. One study reported patient-related outcome measures (PROMS).

Conclusions

In untreated periodontitis patients, laser monotherapy does not yield superior clinical benefits compared with non-surgical mechanical instrumentation alone.

Clinical relevance

In untreated periodontitis patients, mechanical instrumentation with hand and/or ultrasonic instruments remains the standard of care.

Treatment with Nd:YAG Laser Irradiation Combined with Sodium Hypochlorite or Hydrogen Peroxide Irrigation on Periodontal Pathogens: An In Vitro Study

Objective: The purpose of this study was to evaluate the effect of neodymium-doped yttrium aluminum garnet (Nd:YAG) laser with low concentrations of hydrogen peroxide (H₂O₂) or sodium hypochlorite (NaOCl) on viability of oral bacteria. Materials and methods: Bacterial species Streptococcus gordonii, Porphyromonas gingivalis, and Fusobacterium nucleatum were grown in an anaerobic chamber at 37°C. Samples were irradiated with the Nd:YAG laser (1064 nm, 300 μm Varian tip) using parameters: 150 mJ, 20 Hz, 3 W, 50 sec, and 100 μs short pulse duration in contact mode. Treatment groups included (1) control, (2) Nd:YAG, (3) 0.5% H₂O₂, (4) Nd:YAG and 0.5% H₂O₂, (5) 0.5% NaOCl, and (6) Nd:YAG with 0.5% NaOCl. Viable colonies were counted, calculated into colony forming unit/mL, and converted into log form for statistical analysis using a two-tailed paired t-test. Results: The combined treatment with the Nd:YAG and H₂O₂ showed the greatest reduction in all bacterial viability compared with other treatment groups (p < 0.001). Antiseptic solutions and laser were most effective against P. gingivalis, least effective against S. gordonii but improved significantly in combination with laser irradiation (p < 0.001). Laser alone was effective against all of three bacterial species, however, it was not significant. Conclusions: Combination treatment with Nd:YAG laser and an oxidative disinfectant (0.5% NaOCl or H₂O₂) resulted in more effective reduction of bacterial viability than monotherapies.

A Clinical Trial of Photobiomodulation Effect on Orthodontic Microscrews Stability Using a 635 nm Red Laser Light

Background: One of the procedures enhancing implants stability can be photobiomodulation. Objective: To assess the effect of a 635 nm wavelength on orthodontic microscrews stability, survival rate, and an individual patient's pain score. Materials and methods: The study was done with 15 subjects, 30 orthodontic microscrews with a length of 10 mm and diameter 1.4 mm. Implants inserted on the right and left side of the maxilla. The implants in the test group (G1) were irradiated with the laser at palatal and buccal part of peri-implant area (two points). The diode laser (SmartM PRO; Lasotronix, Warsaw, Poland) was used with the following settings: power: 100 mW, spot size: 0.5 cm², mean power density (irradiance): 200 mW/cm², in continuous wave (CW) mode, energy per point: 4 J, radiant exposure: 8 J/cm², time per point: 40 sec, the total energy dose (radiant energy) per session: 8 J in contact mode, handpiece diameter: 8 mm. Laser sessions: day of surgery and 3, 6, 9, 12, 15, 30 days later. Cumulative radiant energy was 59 J. Periotest appliance was used to assess the microscrews stability at day of surgery and 3, 6, 9, 12, 15, 30, 60 days later. Each patient received a survey for individual pain assessment (NRS-11) promptly after the implantation. Results: The analysis after 60 days revealed significantly higher secondary stability for the laser-irradiated microscrews group in comparison with control implants (G2 group) (p = 0.0037). We observed significantly higher stability in the experimental group compared with the control after 30 days (p = 0.0218). Moreover, we noted significantly higher microimplants stability for the control group in comparison with the test group, 9 days after implantation (p = 0.0374). Laser application had no effect on pain reduction noted in the first day in comparison with the control sites (p = 0.6690). No microscrews were lost in the study. Conclusions: Application of a 635 nm laser on peri-implant soft tissue increased the microscrews stability after 30 and 60 days.

Effects of Lasers and Their Delivery Characteristics on Machined and Micro-Roughened Titanium Dental Implant Surfaces

The aim of the study was to investigate the effects of neodymium: yttrium aluminium garnet (Nd:YAG) (1064 nm) and erbium: yttrium aluminium garnet (Er:YAG) (2940 nm) laser energy on titanium when delivered with conventional optics (focusing handpieces or plain ended optical fibres) or with a conical tip. Machined and micro-roughened implant discs were subjected to laser irradiation under a variety of energy settings either dry (without water) or wet (with water). Samples were scanned using a 3D non-contact laser profilometer and analysed for surface roughness, volume of peaks and the maximum diameter of the ablated area. Conical tip designs when used with both lasers showed no surface effect at any power setting on both machined and micro-roughened implant surfaces, regardless of the irrigation condition. When used with conventional delivery systems, laser effects on titanium were dose related, and were more profound with the Nd:YAG than with the Er:YAG laser. High laser pulse energies caused surface fusion which reduced the roughness of micro-roughened titanium surfaces. Likewise, repeated pulses and higher power densities also caused greater surface modifications. The presence of water reduced the influence of laser irradiation on titanium. It may be concluded that conical fibres can reduce unwanted surface modification, and this may be relevant to clinical protocols for debridement or disinfection of titanium dental implants.

Clinical and Microbiological Effects of Weekly Supragingival Irrigation with Aerosolized 0.5% Hydrogen Peroxide and Formation of Cavitation Bubbles in Gingival Tissues after This Irrigation: A Six-Month Randomized Clinical Trial

Introduction

The study investigated the effect of weekly supragingival irrigation with aerosolized 0.5% hydrogen peroxide (H₂O₂) solution as a maintenance periodontal therapy on clinical and microbiological parameters in patients with chronic periodontitis. The other purpose was to investigate whether cavitation bubbles can penetrate not only into periodontitis-damaged tissues but also into ex vivo porcine healthy periodontal tissues.

Materials and Methods

The study included 35 systemically healthy patients with chronic periodontitis (CP). After nonsurgical periodontal debridement (NSPD), all patients were randomized into two groups: the Control group (NSDP alone, n = 18) and the Test group (NSDP plus supragingival irrigation, n = 17). Clinical (Approximal Plaque Index (API), Bleeding Index (BI), and Modified Gingival Index (MGI)) and microbiological (Polymerase Chain Reaction technology (using a micro-IDent® kit)) measurements were performed at the initial time point, 3 months, and 6 months after NSPD. The impact of supragingival irrigation on diseased gingival tissues of CP patients (n = 5) and on ex vivo porcine healthy gingival tissue samples (n = 3) was evaluated to estimate morphological changes in healthy and diseased gingival tissues.

Results

Morphological data revealed that supragingival irrigation caused the formation of cavitation bubbles in diseased gingival tissue of CP patients and in healthy porcine gingival tissues. The decrease in API, BI, and MGI scores after 6 months in the Test group significantly (p ≤ 0.01, p ≤ 0.05, and p ≤ 0.01, respectively) exceeded that in the Control group. Test group patients demonstrated a decrease in periodontal sites showing Pocket Probing Depth > 4 mm and, after 6 months, a statistically significant decrease in the proportion of periopathogenic bacteria.

Conclusion

The effectiveness of mechanical periodontal treatment combined with weekly supragingival irrigation with aerosolized 0.5% H₂O₂ solution on clinical and microbiological parameters of periodontal tissues of periodontitis patients is reliably higher than that of mechanical periodontal debridement alone. It has been found that cavitation bubbles as a result of irrigation with the aerosolized 0.5% hydrogen peroxide solution can form not only in periodontal tissues of periodontitis patients but also in ex vivo porcine healthy gingival tissues.

Photobiomodulation-Underlying Mechanism and Clinical Applications

The purpose of this study is to explore the possibilities for the application of laser therapy in medicine and dentistry by analyzing lasers' underlying mechanism of action on different cells, with a special focus on stem cells and mechanisms of repair. The interest in the application of laser therapy in medicine and dentistry has remarkably increased in the last decade. There are different types of lasers available and their usage is well defined by different parameters, such as: wavelength, energy density, power output, and duration of radiation. Laser irradiation can induce a photobiomodulatory (PBM) effect on cells and tissues, contributing to a directed modulation of cell behaviors, enhancing the processes of tissue repair. Photobiomodulation (PBM), also known as low-level laser therapy (LLLT), can induce cell proliferation and enhance stem cell differentiation. Laser therapy is a non-invasive method that contributes to pain relief and reduces inflammation, parallel to the enhanced healing and tissue repair processes. The application of these properties was employed and observed in the treatment of various diseases and conditions, such as diabetes, brain injury, spinal cord damage, dermatological conditions, oral irritation, and in different areas of dentistry.

Exploring the use of pulsed erbium lasers to retrieve a zirconia crown from a zirconia implant abutment

Background

Removal of cement-retained implant fixed restorations when needed, can be challenging. Conventional methods of crown removal are time consuming and costly for patients and practitioners. This research explored the use of two different types of pulsed erbium lasers as a non-invasive tool to retrieve cemented zirconia crowns from zirconia implant abutments.

Materials and methods

Twenty identical zirconia crowns were cemented onto 20 identical zirconia prefabricated abutments using self-adhesive resin cement. The specimens were divided into two groups for laser assisted crown removal; G1 for erbium-doped yttrium aluminum garnet laser (Er:YAG), and G2 for erbium, chromium-doped yttrium, scandium, gallium and garnet (Er,Cr:YSGG). For the G1, after the first crown removal, the specimens were re-cemented and removed again using the Er:YAG laser. Times needed to remove the crowns were recorded and analyzed using ANOVA (α = 0.05). The surfaces of the crown and the abutment were further examined using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) analyses.

Results

The average times of zirconia crown removal from zirconia abutments were 5 min 20 sec and 5 min 15 sec for the Er:YAG laser of first and second experiments (G1), and 5 min 55 sec for the Er,Cr:YSGG laser experiment (G2). No statistical differences were observed among the groups. SEM and EDS examinations of the materials showed no visual surface damaging or material alteration from the two pulsed erbium lasers.

Conclusions

Both types of pulsed erbium lasers can be viable alternatives for retrieving a zirconia crown from a zirconia implant abutment. Despite operating at different wavelengths, the Er:YAG and Er,Cr:YSGG lasers, perform similarly in removing a zirconia crown from a zirconia implant abutment with similar parameters. There are no visual and elemental composition damages as a result of irradiation with pulsed erbium lasers.

Clinical and Immunological Effects of Er,Cr:YSGG Laser in Nonsurgical Periodontal Treatment: A Randomized Clinical Trial

Objective: The aim of this study was to compare the clinical and immunological results of nonsurgical periodontal treatment with or without the erbium, chromium:yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser. Background data: As lasers have begun to be used in dentistry, the Er,Cr:YSGG laser has started to attract attention in the field of periodontology. Materials and methods: Fifty-nine nonsmoking patients with advanced chronic periodontitis were randomly allocated to a test group (full-mouth ultrasonic supra- and subgingival debridement+Er,Cr:YSGG laser application) and a control group (full-mouth ultrasonic supra- and subgingival debridement+root planing with Gracey curettes). The laser parameters were set as follows: 1.5 W output power, pulse mode H (pulse duration of 140 μs), pulse frequency of 20 Hz, and an air-water spray ratio of 10% air and 15% water. The instrumentation was performed until the operator felt that the root surfaces were adequately debrided. Probing depth (PD), clinical attachment level (CAL), bleeding on probing (BOP), plaque index, interleukin-1 beta (IL-1β), matrix metalloproteinase-8 (MMP-8), tissue inhibitor metalloproteinase-1 (TIMP-1), and MMP-8/TIMP-1 levels in gingival crevicular fluid were evaluated at baseline, 6 weeks, and 3 months postoperatively. Results: There were statistically significant differences in PD, which was our primary outcome, and BOP between the groups at both examinations [p < 0.001 and p < 0.001 (for PD) and p = 0.048 and p < 0.001 (for BOP), respectively], in favor of the laser group. However, there were no significant differences among groups at any time for CAL gain (p = 563 and p = 369, respectively). No significant differences in MMP-8, TIMP-1, and MMP-8/TIMP-1 levels were detected among groups. There was a statistically significant difference for IL-1β levels among groups at 3-month evaluations in favor of the laser group. Conclusions: Using the Er,Cr:YSGG laser instead of hand instruments in nonsurgical periodontal treatment has shown additional improvements in terms of pocket reduction and gingival bleeding compared with traditional nonsurgical therapy.

Q-Switch Nd:YAG Laser-Assisted Elimination of Multi-Species Biofilm on Titanium Surfaces

(1) Background: The relatively high prevalence of peri-implantitis (PI) and the lack of a standard method for decontamination of the dental implant surface have pushed us to conduct further research in the field. Bacterial biofilms were found to play a primordial role in the etiology of PI. Therefore, the aim is to evaluate the efficacy of a laser-assisted elimination of biofilm protocol in the removal of a multi-species biofilm on titanium surfaces. (2) Methods: In total, 52 titanium discs (grade 4) were used. The study group consisted of 13 titanium disks contaminated with multi-species biofilms and subsequently irradiated with the laser (T + BF + L). The control groups consisted of the following types of titanium disks: 13 contaminated with multi-species biofilms (T + BF), 13 sterile and irradiated (T + L), 13 sterile and untreated (T). Q-Switch Nd:YAG laser Irradiation parameters were the following: energy density equal to 0.597 J/cm² per pulse, power equal to 270 milliwatt per pulse, 2.4 mm of spot diameter, and 10 Hz repetition rate for pulse duration of six nanoseconds (ns). The laser irradiation was made during 2 s of total time in non-contact and at 0.5 mm away from the titanium disc surface. After treatment, presence of biofilms on the disks was evaluated by staining with crystal violet (CV), which was measured as optical density at six hundred thirty nm, and statistical analyses were done. (3) Results: the optical density values were 0.004 ± 0.004 for the study group T + BF + L, 0.120 ± 0.039 for group T + BF, 0.006 ± 0.003 for group T + L, and 0.007 ± 0.007 for group T. For the study group, laser treatment resulted in a total elimination of the biofilm, with mean values statistically significantly lower than those of contaminated titanium surfaces and similar to those of sterile titanium surfaces. (4) Conclusions: Our irradiation protocol provided a significant elimination of the multi-species biofilm on titanium surfaces. Laser treated titanium surfaces were biofilm-free, similar to the sterile ones.

Er:YAG Laser Irradiation Reduces Microbial Viability When Used in Combination with Irrigation with Sodium Hypochlorite, Chlorhexidine, and Hydrogen Peroxide

The erbium-doped yttrium aluminum garnet (Er:YAG) laser is used to treat periodontal disease; however, its effectiveness at killing oral bacteria is not well known. Furthermore, the compounding effect of the combination of a laser treatment and irrigation methods with antimicrobials on bacterial viability is yet to be determined. The purpose of this in vitro study was to evaluate the effect of the Er:YAG laser with irrigation using chlorhexidine (CHX), hydrogen peroxide (H₂O₂), or sodium hypochlorite (NaOCl) on the viability of oral bacteria. Three bacterial species were used in our study: Streptococcus gordonii, Fusobacterium nucleatum, and Porphyromonas gingivalis. Bacteria were grown in an anaerobic chamber in brain heart infusion broth and incubated at 37 °C. Bacterial samples with an OD of 0.5 were irradiated with the Er:YAG laser at 2940 nm using a 400-µm Varian tip. The experiment was repeated four times using these parameters: 40 mJ, 40 Hz, and 1.6 W for 20 seconds with the 300 µs short pulse duration in contact mode. Treatment groups consisted of the following: (1) no treatment, (2) 0.5% H₂O₂ alone, (3) 0.5% NaOCl alone, (4) 0.03% CHX alone, (5) Er:YAG irradiation alone, (6) Er:YAG irradiation with 0.5% H₂O₂, (7) Er:YAG irradiation with 0.5% NaOCl, and (8) Er:YAG irradiation with 0.03% CHX. Microbial viability was determined through plating and colony counts and calculated into CFU/ml. Statistical analysis was done using a two-tailed paired t-test. The use of the Er:YAG laser alone failed to show statistically significant antibacterial activity against any of bacteria. The most effective mono-treatment with irrigation solutions for all three bacteria were 0.5% H₂O₂ and 0.5% NaOCl (p < 0.001 for each solution). Irrigation with 0.03% CHX was most effective against F. nucleatum (p < 0.01) and less against P. gingivalis and S. gordonii and showed the least antibacterial action alone but improved significantly in combination therapy (p < 0.05). The combined treatment with the Er:YAG showed the greatest and most significant improvement in the reduction of bacterial viability compared to any other treatment group (p < 0.05 for each combined treatment). Irradiation with the Er:YAG laser with the addition of 0.5% H₂O₂, 0.5% NaOCl, or 0.03% CHX under a short working time (20 s) resulted in a significant reduction of bacterial viability for all three bacterial species compared with any single treatment option. The combination of irradiation with the Er:YAG laser with the addition of 0.5% H₂O₂, 0.5% NaOCl, or 0.03% CHX resulted in a larger reduction of bacterial survival when compared to monotherapies with antimicrobial solutions or laser. The combination of the Er:YAG laser with a low concentration irrigant solution of 0.5% H₂O₂, 0.5% NaOCl, or 0.03% CHX could be an effective treatment protocol for the reduction of periodontal pathogens and thus suitable treatment for non-surgical periodontal therapy.

Transurethral resection in women with symptomatic keratinizing squamous metaplasia of urinary bladder: A retrospective study of 92 cases

Objectives

To investigate the efficacy of transurethral resection (TUR) on relieving urinary symptoms in patients with keratinizing squamous metaplasia (KSM) of the urinary bladder.

Methods

Data were analyzed from a retrospective study of patients receiving transurethral bipolar plasma resection (bi‐TUR) treatment for symptomatic KSM. Urinary symptoms were assessed by the International Prostate Symptom Score (IPSS) and a numeric rating scale pain score. Efficacy was assessed using the IPSS to determine changes from baseline in lower urinary tract symptoms (LUTS). Self‐reported quality of life (QoL) was assessed by the last question of the IPSS questionnaire.

Results

A total of 92 female patients were included in the analysis. The median age was 42 years. LUTS, pain, and hematuria were the most common symptoms that affected patients. The median follow‐up duration was 51 months. There were significant improvements in LUTS from baseline IPSS after TUR (P < .001). The percentage of the patients with moderate to severe LUTS went down from 52.2% to 18.5%. The median Numeric Rating Scale (NRS)‐11 pain score reduced from 3 at baseline to 0 at the last visit. Twenty‐one out of 40 patients reported that the pain symptoms disappeared completely. No patients reported hematuria symptoms at the final follow‐up. Improvement of self‐reported QoL was significant (P < .001). A total of 57.6% of patients reported an improvement, 26.1% of patients reported no improvement, and 16.3% reported deterioration.

Conclusions

Bi‐TUR therapy significantly relieved urinary symptoms in women with KSM. Improvement of QoL was acceptable with a success rate of 57.6%. Considering the very low complication rate, our study supported bi‐TUR as an alternative treatment for patients who are resistant to medical therapy.

Photonic Therapy in Periodontal Diseases an Overview with Appraisal of the Literature and Reasoned Treatment Recommendations

Recent reviews and meta-analyses of the literature over the past quarter-century have failed to provide enough evidence to prove or disprove the actual utility of photonic therapy in periodontitis, alone or adjunctive to conventional approaches. This apparent paradox has been explained by the many physical, molecular, biological, anatomical, and technical variables of photonic treatments, which can differ in light-emitting devices (laser or LED), wavelengths, irradiation power and modes, clinical objectives, follow-up times, disease grading, and assessment methods. This multi-faceted, controversial scenario has led practitioners to underestimate the actual potential of photonic therapy in periodontal diseases. In this critical appraisal of the literature, we have briefly summarized the main photonic therapies and instruments used in Periodontology, highlighting their main characteristics and limitations. Then, we have tried to identify and discuss the key methodological issues which can have an impact on the outcome of photonic therapies. Our main goal was to identify the best parameters, settings, and methodologies to perform effective periodontal photonic treatments and to extrapolate some recommendations for clinical use. Should these recommendations find a consensus among periodontologists and be adopted in future clinical studies, they will hopefully contribute to dissipate the present confusion and uncertainty on this complex matter.

Effect of Different Laser Wavelengths on Periodontopathogens in Peri-Implantitis: A Review of In Vivo Studies

Nowadays, many studies are examining the effectiveness of dental lasers in the treatment of peri-implantitis; however, most of them only report periodontal parameter changes. The authors of this review tried to address the question: “What is the effect of different laser wavelengths on oral bacteria that cause peri-implantitis?” An electronic search of PubMed and Cochrane Central Register of Controlled Trials was performed. The following search terms were used: (peri-implantitis OR periimplantitis) OR/AND (microbial OR microbiologic) AND (laser OR Er:YAG OR erbium OR diode OR Nd:YAG OR neodymium-doped OR Er,Cr:YSGG OR chromium-doped). Initially, 212 studies were identified. After screening the titles and abstracts and excluding studies according to predefined inclusion criteria, seven publications were included in the review. Three studies about the effect of aPDT (antimicrobial photodynamic therapy) reported a decrease in the different bacterial strains associated with peri-implantitis, e.g., A. actinomycetemcomitans, P. gingivalis, P. intermedia, T. denticola, T. forsythia, F. nucleatum, and C. rectus. Two studies showed that the high-power diode laser may have some effect on peri-implant pathogens. Two articles about the Er:YAG laser reported a lowering in the count of oral pathogens; however, it was hard to determine if this was due to the use of the laser. aPDT has the ability to decrease the count of peri-implant pathogens, whereas Er:YAG laser application shows no significant effect on oral bacteria in the long term.