Effect of diode laser irradiation on root surfaces in vitro

Assessment of clinical efficacy of 445 nm Diode laser as an adjunct to Kirkland flap surgery in the management of periodontitis - a split mouth randomized clinical trial

Aim of this study is to assess the clinical efficacy of 445 nm Diode laser as an adjunct to Kirkland flap surgery in management of periodontitis. Type of study is a Split mouth clinical trial in which a total of 13 patients were recruited based on specific inclusion and exclusion criteria. In each participant, random allocation of selected sites into test and control in contralateral quadrants was done. Clinical parameters such as probing depth and clinical attachment loss was measured in control and test sites using occlusal stents. Flap surgery was carried out 6 weeks after phase I therapy and the selected contralateral sites with a probing depth of > 5mm were subjected to surgical therapy. In a test quadrant, 445 nm diode laser with a power of 0.8 W, CW mode, 320 µm fiber, in non-contact mode was used as an adjunct to flap surgery. Primary outcome variable assessed was change in PPD between baseline, pre-operative, 1-, 3- and 6-months post-surgery. Secondary outcomes variables assessed were Clinical attachment loss at baseline, pre-operative, 1, 3 and 6 months, visual analog scale at days 3 and 7 and patient satisfaction index at day 7 post surgery. Surgery for the second site (Test/control) in the contralateral quadrants was performed 1 week after the first surgery. A higher reduction in probing depth and gain in CAL was observed in test site at 1, 3 and 6 months follow up amongst all the included participants. VAS score was lower at the test site as compared to the control sites. PSI scores were similar in both the sites. The adjunctive use of 445nm diode laser to surgical periodontal therapy contributed to improved short term clinical outcomes as assessed at the end of 6 months post- surgery. VAS score indicative of post -surgical discomfort were also lower for the laser treated sites. Hence adjunctive use of laser (445 nm wavelength) can be recommended for achieving more predictable clinical outcomes.

Effectiveness of Diode (810 nm) Laser in Periodontal Parameters and Reduction of Subgingival Bacterial Load in Periodontitis Patients

AIM

This split-mouth randomized trial (RCT) aimed to assess the effect of diode laser on the clinical parameters in patients with periodontitis, compare the results with scaling and root planing (SRP) alone, and assess the implications of diode laser (DL) on plaque bacteria.

MATERIALS AND METHODS

Seventeen periodontitis patients were randomly assigned into two equal groups based on the therapy delivered. Group I (control site) received just SRP at baseline, while group II (test site) received both SRP and DL irradiation. For both groups, the clinical periodontal parameters probing pocket depth (PPD), and clinical attachment level (CAL) were measured at baseline, 30 days, and 90 days. Microbiological amount was also measured at baseline, 30, and 90 days after periodontal treatment. The amounts of Aggregatibacter actinomycetemcomitans (A.a), Prevotella intermedia (Pr. intermedia), and Porphyromonas gingivalis (P. gingivalis) were determined using real-time PCR probing with specific bacterial primers.

RESULTS

In both groups, PPD and CAL showed statistically significant reductions at different time intervals (p < 0.05). No significant difference were observed in CAL values after 1 and 3 months in both test and control groups (p > 0.05). The mean values of the concentration of A.a, Pr. intermedia and P. gingivalis were lower in the case group as compared to the control group and the difference was statistically significant after 1 month (*p = 0.001).

CLINICAL SIGNIFICANCE

According to this study, non-invasive laser treatment has the potential to improve clinical outcomes by lowering the quantity of A.a, Pr. intermedia and P. gingivalis.

CONCLUSION

In both groups, a considerable decrease in the periodontal pathogens A.a, Pr. intermedia and P. gingivalis were discovered; however, the intergroup comparison was insignificant in relation to PD and CAL. The adjunctive treatment with diode laser showed better efficacy in ensuring a better periodontal treatment than SRP alone. How to cite this article: Abdullah LA, Hashim N, Rehman MM, et al. Effectiveness of Diode (810 nm) Laser in Periodontal Parameters and Reduction of Subgingival Bacterial Load in Periodontitis Patients. J Contemp Dent Pract 2023;24(12):1008-1015.

Minimally invasive management of vital teeth requiring root canal therapy

The present study aimed to investigate the possible use of a non-instrumentation technique including blue light irradiation for root canal cleaning. Extracted human single rooted teeth were selected. Nine different groups included distilled water, NaOCl, intra-canal heated NaOCl, and NaOCl + EDTA irrigation after either instrumentation or non-instrumentation, and a laser application group following non-instrumentation technique. The chemical assessment of the root canal dentine was evaluated using energy dispersive spectroscopy (EDS) and Fourier transform infrared (FT-IR) spectroscopy. Surface microstructural analyses were performed by using scanning electron microscopy (SEM). The antimicrobial efficacy of different preparation techniques was evaluated using microbial tests. Light application didn't change the calcium/phosphorus, carbonate/phosphate and amide I/phosphate ratios of the root canal dentin. The root canal dentin preserved its original chemistry and microstructure after light application. The instrumentation decreased the carbonate/phosphate and amide I/phosphate ratios of the root canal dentin regardless of the irrigation solution or technique (p < 0.05). The application of light could not provide antibacterial efficacy to match the NaOCl irrigation. The NaOCl irrigation both in the non-instrumentation and instrumentation groups significantly reduced the number of bacteria (p < 0.05). The use of minimally invasive root canal preparation techniques where the root canal is not instrumented and is disinfected by light followed by obturation with a hydraulic cement sealer reduced the microbial load and preserved the dentin thus may be an attractive treatment option for management of vital teeth needing root canal therapy.

Comparative Evaluation of Conventional Therapy With and Without Use of Diode Laser (DL) in the Treatment of Chronic Generalized Periodontitis: A Clinico-Microbiological Study

INTRODUCTION

Chronic periodontitis is caused by a persistent and expanding interaction between a subgingival pathogenic microbial biofilm and the host immune system. The host's reaction to local factors directly influences the inflammation and bone loss that result from these interactions. Depending on variables like the severity of soft tissue damage and bone loss, treatment options can range from nonsurgical to surgical. Nonsurgical treatments are frequently used as the first-line therapy for inflammatory periodontal disease. In fact, careful scaling and root planing (SRP), a nonsurgical treatment, has been extensively studied and shown to be a highly predictable and effective therapy. According to recent research, using a diode laser (DL) in addition to standard SRP may reduce bacterial count and reinfection significantly. Laser therapy could be helpful in treating periodontal disease because of its antibacterial and detoxifying effects. The goal of this study is to investigate whether using a DL in addition to conventional flap surgery enhances patient outcomes for those with chronic generalized periodontitis.

MATERIALS AND METHODS

The 12 participants in this split-mouth trial with chronic generalized periodontitis were the main subject of the study. All of them had probing pocket depths (PPDs) of at least 5 mm after the initial phase of treatment. Each patient in the control group (Group A) and test group (Group B) received a conventional flap after being randomly assigned to one of the groups. Group B underwent a conventional flap with a 980 nm DL, whereas those in Group A did not receive any DL therapy. Periodontal pockets in both groups were evaluated at baseline, 45 days, and 90 days after a sub-gingival plaque test. Quantitative real-time polymerase chain reactions were used to examine the presence of red complex organisms in the plaque sample.

RESULTS

From baseline to 45 days and then to 90 days, clinical attachment loss (CAL), plaque index (PI), and gingival index (GI) all significantly decreased. However, results from 45 days to 90 days were statistically non-significant, with the exception of the GI, where Group B results were significantly different from Group A results from 45 days to 90 days. On the other hand, when a DL was combined with conventional flap surgery in the test group, the quantity of red complex bacteria was significantly decreased.

CONCLUSION

When DL was used in conjunction with conventional flap surgery, the results showed that CAL, PI, and GI were all significantly reduced while the quantity of red complex bacteria was also significantly decreased.

Evaluation of structural and compositional changes on the root surface exposed to diode laser (810 nm): An In-vitro study

Background

The laser therapy has been used as an adjuvant for conventional periodontal disease as they exhibit a bactericidal effect on scaling and root planning by its thermal and photo disruptive effects on the pathogens. This study focuses on the structural and compositional changes induced on the root surfaces of teeth following diode laser (DL) application with increasing quantum of exposure time.

Objective

The objective of this study was to evaluate the structural and compositional changes on the root surface of extracted human permanent teeth after application of DLs (810 nm) with varying time interval.

Materials and Methods

Twenty samples of single-rooted periodontally compromised extracted teeth were utilized for this study. Root planning was done and the roughness caused by the instrumentation was measured using profilometric analysis. Then, the samples were divided into four groups, with DL application time: Group 1 - laser application for 15 s, Group 2 - laser application for 30 s, Group 3 - laser application for 45 s, and Group 4 - laser application for 60 s. A scanning electron microscope was used to examine the cemental surface and energy-dispersive X-ray analysis software assesses the compositional changes of the teeth in each group.

Results

This study reveals that on exposure of DL (810 nm) on the root surface when time of exposure increases, there were relative increases in surface irregularities and charring. There were significant changes in the chemical composition of the tooth surface.

Influence of irrigation and laser assisted root canal disinfection protocols on dislocation resistance of a bioceramic sealer

BACKGROUND

It is not yet clear how different irrigation protocols and intracanal laser irradiation effects bioceramic sealers. In this vitro study, we aimed to evaluate the dislocation resistance of a bioceramic root canal sealer after different laser-assisted disinfection protocols and irrigants.

METHODS

Sixty extracted human straight single-canal teeth were instrumented, and randomly divided into five experimental groups (n=10) according to the disinfection protocol used: group 1, conventional needle irrigation (CI) with sodium hypochlorite (NaOCl)+ethylenediaminotetraacetic acid (EDTA)+NaOCl; group 2, Photon initiated photoacoustic streaming (PIPS) of NaOCl+EDTA+NaOCl; group 3, NaOCl+EDTA+diode laser; group 4, NaOCl+EDTA+photodynamic therapy (PDT); group 5, CI with NaOCl+EDTA+Chlorhexidine (CHX); and control group without any treatment. The root canals were filled with a bioceramic root canal sealer (BioRoot RCS) using the single-cone filling technique. After three weeks of storage, the samples from each canal thirds were transversely sectioned and the push-out test was performed.

RESULTS

The PIPS group showed the lowest dislocation resistance values in the coronal third (p>0.05), and no difference was observed among the other groups (p<0.05). The dislocation resistance in the middle and apical thirds was the highest in the diode laser group (p<0.05).

CONCLUSION

Final root canal irradiation with diode laser led to improved dislocation resistance of the bioceramic sealer. PDT did not adversely affect the dislocation resistance of BioRoot RCS. The PIPS reduced the dislocation resistance values in the coronal third, but not in the middle and apical thirds.

Efficacy of Periodontal Endodontics Combined with Diode Laser (DL) Therapy on Severe Periodontitis

Background

For a long time, the impact of severe periodontitis on the pulp has been the focus of periodontal clinical research. Whether the teeth with severe periodontitis should be treated with pulp has also become the focus of clinical research.

Aims

To explore the effect of periodontal endodontic therapy combined with DL therapy on severe periodontitis.

Materials and Methods

The clinical data of 100 patients with severe periodontitis from January 2020 to July 2022 were selected and included in the retrospective study. According to the different retrieval treatment methods, they were divided into the control group and the treatment group with 50 cases in each group. The control group received periodontal endodontic treatment, and the treatment group received DL treatment on the basis of the control group. The differences in periodontal probing depth (PD), toothache degree, bleeding index (BI), inflammatory factors, plaque index (PLI), and attachment loss (AL) between the two groups were compared and analyzed.

Results

After 3 months of treatment, the bleeding index (BI), plaque index (PLI), and periodontal probing depth (PD) of the treatment group were significantly lower than those of the control group, and the difference was statistically significant (P < 0.05). The attachment loss (AL) of the group was not significantly different from that of the control group (P > 0.05). Before treatment, there was no significant difference in the levels of inflammatory factors between the two groups (P > 0.05). After 3 months of treatment, the levels of IL-6 and CRP in the treatment group were significantly lower than those in the control group, and the difference was statistically significant (P < 0.05). Before treatment, there was no significant difference in the levels of inflammatory factors between the two groups (P > 0.05). After 3 days of treatment, the VAS score of the treatment group was significantly lower than that of the control group, and the difference was statistically significant (P < 0.05).After treatment, there were no complications during follow-up in the two groups.

Conclusion

The application of DL treatment has a significant effect, which can promote the healing of periodontal tissue, reduce the depth of periodontal pockets, and reduce the degree of toothache, thereby providing a reference for clinical treatment.

Er,Cr:YSGG Laser as a Means of Orthodontic Adhesive Removal: Myth or Reality?

Objective: This study aimed to compare the effect of Er,Cr:YSGG laser with a tungsten carbide bur in orthodontic finishing on the enamel surface roughness and the heat generated in the pulp chamber. Methods: Before bonding, of 125 intact extracted premolar teeth, 15 teeth were randomly assigned to the control group. Of the remaining 110 bonded teeth, 50 were used to determine the laser parameters, and 60 were included in the main in vitro study. After debonding, the teeth were randomly distributed among four study groups (n = 15) for finishing with laser beams (Er,Cr:YSGG, Waterlase) with and without polishing with Sof-Lex discs, and finishing with a bur (tungsten carbide, Reliance) with and without polishing with Sof-Lex discs. The thermal changes were measured during finishing using a thermo-controller-coupled thermocouple placed in the pulp chamber. Enamel surface roughness was evaluated qualitatively under a scanning electron microscope (SEM) and quantitatively under an atomic force microscope (AFM). Results: The thermal changes of the bur group were significantly higher than those in the laser group (p = 0.0001). Quantitatively, the surface roughness values of all the study groups were significantly higher than those of the control group (p < 0.05), with no significant difference between the study groups (p > 0.05). SEM analysis confirmed the AFM measurements. Conclusions: Er,Cr:YSGG can be recommended as an alternative for a carbide bur for adhesive agent removal after orthodontic debonding, considering its mild thermal effect on the pulp. Polishing with Sof-Lex discs did not significantly reduce the surface roughness, regardless of the finishing procedure.

Impact of Adjunctive Diode Laser Application to Non-Surgical Periodontal Therapy on Clinical, Microbiological and Immunological Outcomes in Management of Chronic Periodontitis: A Systematic Review of Human Randomized Controlled Clinical Trials

Background

Due to the limitations of scaling and root planing (SRP) in chronic periodontitis (CP) management, research has been focused on utilising additional therapies to enhance conventional treatment methods. The present systematic review is aimed to appraise the accessible scientific evidence of in vivo human studies to establish the effectiveness of adjunctive diode (λ 808- λ 980nm) laser treatment to SRP in CP.

Methodology

This systematic review was conducted following the PRISMA statement guidelines. The review protocol is registered in PROSPERO (CRD 42021227695). The search strategies were based on structured electronic and manual (with appropriate keywords) and were conducted to collect the applicable published data on RCTs studies (in vivo human), spanning over ten years between August 2010 and August 2020. The articles were selected to address the following research focus question: “Does diode laser (λ 808- λ 980nm) therapy have superior effects as an adjunct to SPR, compared to SRP alone, in terms of clinical or microbiological or immunological profiles in the management of CP?”

Results

Fifteen articles met the eligibility criteria and are included in this review. A wide range of discrepancies and inconsistencies were shown in the outcomes of the laser and SPR treatment modality, compared to SRP alone. The data on standardised study protocol, optimal laser parameters and outcome measurements were inconclusive, and a high risk of bias in the majority of the studies observed, which are crucial in establishing a homogenous and reproducible protocol.

Conclusion

In light of the confined evidence-based data and critical evaluation of this systematic review, the efficacy of adjunctive diode laser treatment ranging between 808 and 980nm to SRP remains debatable. The observational quality of the present systematic review was emphasised after scrutinising the available data, and an attempt to propose a laser protocol for future RCTs consideration was a great challenge due to an absence of clear and standardised recommendations in delivering a reliable laser protocol which can be replicable by future investigators. RCTs with robust methodology are warranted.

In vivo investigation of diode laser application on red complex bacteria in non-surgical periodontal therapy: a split-mouth randomised control trial

Assessment of the efficacy of a single 810 nm diode laser application as an adjunctive treatment modality during the first intervention of non-surgical periodontal therapy (NPT). 25 patients diagnosed with chronic periodontitis underwent a split-mouth randomised control trial. The periodontal pockets of the test quadrants were treated with an 810 nm diode laser as an adjunct to NPT (Picasso GaAlAs; AMD Lasers). The laser was set at 1.0 W continuous wave, 400 µm tip, 796 W/cm² peak power density and a 32 J/cm² energy density. Therapeutic outcomes were evaluated based on the clinical parameters, which included probing pocket depth, recession, clinical attachment level, full mouth plaque score, full mouth bleeding on probing and tooth mobility. The baseline bacterial collection was completed from the periodontal pockets and then re-evaluated at 6 weeks. Clinical parameters demonstrated no statistical difference, with the exception of a statistically significant (P < 0.05) reduction in bleeding on probing for the test side. The test side resulted in a statistical increase of Capnocytophagaspecies and Treponemadenticola. The single application of the diode laser did not significantly improve the bacterial nor the clinical parameters in patients with chronic periodontitis.

Trial registration number: PACTR201909915338276.

Can We Determine an Appropriate Timing to Avoid Thermal Pulp Hazard During Gingivectomy Procedure? An In Vitro Study with Diode Laser

Objective: Diode laser (DL) is a frequently preferred tool for soft tissue incision and ablation in oral surgery. The aim of this study was to find the most effective irradiation time protocol to avoid potential harmful temperature rise in pulp during DL-assisted gingivectomy. Materials and methods: Ninety human freshly extracted teeth (30 anterior, 30 premolar, and 30 molar) were irradiated using a 940 nm DL with power output of 1 and 2 W and exposure time of 10, 20, 30, 40, 50, and 60 sec per specimen. Intrapulpal temperature was evaluated with thermocouple. Additionally, the effect of dark deposits on root surface for intrapulpal temperature rise was investigated. Temperature differences with every 10 sec were evaluated for three different teeth types, and statistical analyses were performed. Results: Anterior and premolar teeth exceeded the threshold values earlier than molar teeth for both 1 and 2 W. Despite the significant differences among the types of teeth, at 10 sec, temperature rise recorded for all types of teeth was below the critical value of 5.6°C, which cause pulp damage. Dark deposits on teeth surface boosted thermal effect of DLs (p < 0.01). Conclusions: Gingivectomy with DLs at 1 W on anterior, premolar, and molar teeth for 20, 40, and 60 sec, respectively, generates acceptable temperature rise; however, it should be <10, 20, and 40 sec at 2 W, respectively. Especially in the anterior teeth, DLs should be performed with caution to avoid pulp damage.

Influence of an 810-nm Diode Laser on the Temperature Changes of the External Root Surface: An In Vitro Study

Background and Aims:

Rising effects of temperature due to laser use during root canal disinfection may harm periodontium and alveolar bone. Therefore, the aim of this study was to estimate the surface root temperature of lower incisors throughout the application of different power levels and times of an 810-nm diode laser.

Materials and Methods:

Sixty single-rooted extracted human lower incisor teeth were selected and chemomechanical preparation was performed. Specimens were irradiated using 810-nm diode laser at 1.05, 1.5, and 1.95 W power settings and two periods of time 20 and 60s, in a continuous wave (CW) mode, without water spray. Specimens were divided into three main groups (n = 20). Each group was subdivided into two subgroups (n = 10). Then, the peak temperatures at the middle and apical regions of the root surface were registered using a thermocouple.

Results:

Temperature rise of root surface at all the selected output powers was below 7°C. The highest temperature value was obtained in the apical region at 60s when the root canal irradiated at 1.95 W output power.

Conclusion:

Diode laser is safe for use as a root canal disinfectant. Time of exposure to laser irradiation has an effect on the temperature difference at different output powers.

Comparative evaluation of use of diode laser and electrode with and without two dentinal tubule occluding agents in the management of dentinal hypersensitivity: An experimental in vitro study

Background:

The present study aims to assess area of open dentinal tubules by use of diode laser and electrode alone and in combination with hydroxyapatite powder and strontium chloride powder by using the scanning electron microscope (SEM).

Materials and Methods:

A double-blinded study was carried out with 30 extracted teeth with no carious lesion or restored teeth were selected and grouped randomly as Group A - diode laser, Group B - electrode application, Group C - hydroxyapatite powder plus diode laser, Group D - hydroxyapatite powder plus electrode application, Group E - strontium chloride powder plus diode laser, and Group F - strontium chloride powder plus electrode application. All the samples were made by preparing a notch of 2 mm measured with UNC-15 probe at cementoenamel junction using a diamond cylindrical bur at high speed. The teeth were then washed with distilled water and stored in solution containing 2.5% glutaraldehyde solution in 0.1 M sodium phosphate buffer for 24 h. The samples were treated as mentioned in above said groups and were viewed under SEM the degree of occlusion of the dentinal tubules were quantified using an image analyzer.

Results:

Highest number of open dentinal tubules was found with Group B, that is, electrode application, whereas Group C, that is, hydroxyapatite powder plus diode laser showed highest occluded tubules. One-way ANOVA showed statistically significant difference across all the groups (P = 0.000); further, intergroup comparison with Tukey's test showed better tubular occlusion with Group C.

Conclusion:

The SEM results showed highest tubular occlusion with hydroxyapatite powder plus diode laser and least with electrode.

Diode Laser as an Adjunct to Kirkland Flap Surgery-A Randomized Split-Mouth Clinical and Microbiological Study

Background: Mechanical methods of periodontal therapy alone may fail to eliminate the tissue-invasive pathogenic flora; therefore, considerable attention has been given to adjunctive antimicrobial measures. Objective: The aim of this study was to investigate and compare the clinical and microbiological effects of diode laser (DL) as an adjunct to Kirkland flap surgery versus Kirkland flap surgery alone for the treatment of generalized chronic periodontitis. Materials and methods: A total of 20 patients with generalized chronic periodontitis with probing pocket depth ≥5 mm after phase I therapy were included in this split-mouth study. Two contralateral quadrants of each patient were randomly assigned to either test or control group. Control group was treated with Kirkland flap surgery alone, whereas test group was treated with DL as an adjunct to Kirkland flap surgery. Periodontal parameters were recorded, and subgingival plaque samples were collected from both the control and test groups at baseline and third and sixth month. The plaque samples were then analyzed for red complex organisms using quantitative real-time polymerase chain reaction. Results: Compared with baseline, both treatments showed an improvement in periodontal parameters at the third and sixth month. However, test group produced a significant improvement in plaque index (1.039 ± 0.069 vs. 1.392 ± 0.17, p < 0.001), bleeding on probing (16.512 ± 5.982 vs. 37.051 ± 7.459, p < 0.001), probing pocket depth (1.727 ± 0.39 vs. 3.016 ± 0.47, p < 0.001), and clinical attachment level (2.054 ± 0.524 vs. 3.354 ± 0.728, p < 0.001) at third and sixth month compared with the control group. Moreover, in the test group, levels of red complex bacteria were significantly reduced at third and sixth month compared with the control group. Conclusions: DL as an adjunct to Kirkland flap surgery has resulted in a greater reduction in clinical and microbiological parameters compared with Kirkland flap surgery alone, thereby offering additional benefit in treating generalized chronic periodontitis patients.

In vitro effect of diode laser against biofilm of Aggregatibacter actinomycetemcomitans

Objective:

The main objective is to investigate the antibacterial effect of diode laser against Aggregatibacter actinomycetemcomitans biofilm.

Materials and Methods:

Biofilms of A. actinomycetemcomitans plus Streptococcus sanguinis grown on bovine root surfaces were treated with an 810-nm diode laser using a noncontact pulsed mode with a pulse interval and pulse length of 20 ms. Four protocols, that is, one episode of 1.5 or 2.5 W for 30 s and three episodes of 1.5 or 2.5 W for 30 s were tested. No treatment and 0.2% chlorhexidine treatment served as negative and positive controls, respectively. Viable bacterial number was determined by colony counting.

Results:

Treatment with chlorhexidine and all laser protocols except that using single episode of 1.5 W reduced the number of A. actinomycetemcomitans in either single-species or dual-species biofilm compared to negative control. A higher percentage of A. actinomycetemcomitans reduction was demonstrated after increasing the power output or repeating the irradiation.

Conclusions:

The laser protocols used in this study could reduce the number of viable bacteria but not eradicate A. actinomycetemcomitans biofilm.

Effect of Diode Laser-assisted Flap Surgery on Postoperative Healing and Clinical Parameters: A Randomized Controlled Clinical Trial

Background and Objectives:

Lasers have been widely used because of several potential benefits such as antibacterial effect and stimulation of wound healing. In addition, lasers help in hemostasis and delaying epithelial migration which may facilitate the outcome of flap surgery. Hence, this study is aimed to investigate the adjunctive effect of diode laser irradiation on conventional access flap surgery in the treatment of periodontal disease.

Materials and Methods:

A total of 23 patients requiring periodontal flap surgery in two sextants with probing pocket depth ≥5 mm in at least three teeth post-phase I therapy were selected for a split-mouth study. Flap surgery with adjunctive diode laser irradiation was performed in the test quadrant while conventional access flap surgery was done in the control quadrant. Procedural pain and tissue response of the patients were evaluated at 3, 7, and 14 days postoperatively. Clinical parameters including probing depth, clinical attachment level, plaque index, and gingival index were recorded at baseline, 3 months, and 6 months following treatment.

Results:

There is no significant difference between the groups with respect to healing response of tissues; however, patients experienced more pain in test sites compared to control sites. Intragroup comparisons showed a statistically significant reduction of all clinical parameters from baseline to 6 months without any significant difference between the groups.

Conclusion:

Overall within the limitations of the study, diode lasers did not show any significant added benefits over conventional access flap surgery.

Comparative Evaluation of Efficacy of Iontophoresis with 0.33% Sodium Fluoride Gel and Diode Laser Alone on Occlusion of Dentinal Tubules

INTRODUCTION

Dentinal Hypersensitivity (DH) is one of the most commonly encountered clinical problems. Literature reveals no specific therapy to satisfactorily eliminate dentinal hypersensitivity.

AIM

The aim of this study was to assess and compare the efficacy of iontophoresis with 0.33% Sodium Fluoride (NaF) gel and diode laser alone in dentinal tubule occlusion.

MATERIALS AND METHODS

This in vitro study included 20 teeth with intact root surfaces unaltered by extraction procedure for specimen preparation. Each tooth was cleaned, air dried and cut into three sections. Total 60 sections were prepared (30 longitudinal and 30 transverse sections), which were acid etched. In control group, no treatment was carried. In iontophoresis treatment group, samples were inserted into a foam tray containing 0.33 % NaF Gel and subjected to 1.5 mA output current for three minutes. In laser treatment group, specimens were lased with 980 nm diode laser at 0.5 W/PW (62.2J /cm²) in a noncontact mode for 30 seconds. Specimens were evaluated under Scanning Electron Microscope (SEM) at 10KV to 20KV under x 2000, x5000 magnification for surface characteristics and patency of dentinal tubules. Total number of tubules visible, open, completely and partially occluded were recorded in each microphotograph and compared.

RESULTS

On comparison, laser group showed the least number of open tubules i.e., 130 (31.1%) followed by iontophoresis group, 155 (51.32%) and control group 417 (100%).

CONCLUSION

Diode laser application provided better results as compared to iontophoresis on occlusion of dentinal tubules. Hence, it can be used to treat the patients with DH.

Periodontal and peri-implant wound healing following laser therapy

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

Anti-infective therapy with an Er:YAG laser: influence on peri-implant healing

In addition to conventional treatment modalities (mechanical and chemical), the use of lasers has been increasingly proposed for the treatment of periodontal and peri-implant infections (i.e., cleaning and detoxification of implant surfaces). Preliminary results from basic studies have pointed to the high potential of the Erbium-doped: Yttrium, Aluminum and Garnet (Er:YAG) laser. Furthermore, preliminary clinical data indicate that treatment with this kind of laser may positively influence peri-implant healing. The aim of this research update is to evaluate, based on the currently available evidence, the use of an Er:YAG laser for the treatment of peri-implant infections and to indicate its potential as a new treatment modality.

Dentinal tubules sealing by means of diode lasers (810 and 980 nm): a preliminary in vitro study

OBJECTIVE

The aim of this study was to evaluate the effect on dentinal surfaces of diode lasers (810 and 980 nm) at different parameters.

MATERIALS AND METHODS

Twenty-four caries-free human impacted wisdom teeth were used. The crowns were sectioned transversely in order to expose the dentin. The smear layer was removed by a 1 min application of ethylenediaminetetraacetic acid (EDTA). Each surface was divided into four quadrants irradiated at a different output power setting for each kind of laser: 0.8, 1, 1.6, and 2 W (energy densities: 2547, 3184, 5092, and 6366 J/cm(2), irradiation speed 1 mm/sec; optical fiber diameter: 200 μm; continuous and noncontact mode). Half of the samples were stained with a graphite paste. All specimens were sent for scanning electron microscopic (SEM) analysis. Pulp temperature increases in additional 20 teeth were measured by a thermocouple.

RESULTS

Diode laser irradiations at 0.8 and 1 W led to occlusion or narrowing of dentin tubules without provoking fissures or cracks. The application of graphite paste increased the thermal effects in dentin. Measurements of pulp temperature showed that irradiations at 0.8 and 1 W for a period of 10 sec in continuous mode increased pulp temperature (T ≤2°C).

CONCLUSIONS

Diode lasers (810 and 980 nm) used at 0.8 and 1 W for 10 sec in continuous mode were able to seal the dentin tubules. These parameters can be considered harmless for pulp vitality, and may be effective in the treatment of dentinal hypersensitivity.

Effects of laser-aided circumferential supracrestal fiberotomy on root surfaces

OBJECTIVE

To evaluate and compare the effects of circumferential supracrestal fiberotomy in vivo (using diode, CO(2), and Er∶YAG lasers) on the morphology and chemical composition of the root surface.

MATERIALS AND METHODS

Forty healthy premolar teeth, intended for extraction for orthodontic reasons, were used in this study. Root surfaces were treated using different laser methods, as follows: (1) control; (2) Er∶YAG laser (2.94 µm, 100 mJ, 10 Hz); (3) diode laser (808 nm, 1.2 W, continuous wave); and (4) CO(2) laser (10.6 µm, 3 W, continuous wave). Subsequently, the teeth were removed and subjected to scanning electron microscopic (SEM) examination and energy dispersive x-ray (EDX) spectrometric analysis.

RESULTS

SEM analysis indicated that no thermal changes, including melting or carbonization, were observed following the lasing procedures. EDX analysis showed that the laser procedures resulted in similar mineral contents (weight % of calcium and phosphate) as compared to those in the control group.

CONCLUSION

Based on these findings, we concluded that laser-aided procedures, when used at appropriate laser settings, preserve the original morphology and chemical composition of cementum.

A report of laser-assisted modified Widman flap for periodontal regeneration: Clinical and radiographic evaluation

Periodontitis is a relatively common disease. Various therapies have been recommended for its treatment which includes nonsurgical, antimicrobial, and surgical therapy. In recent years lasers have been used for all the three above-mentioned purposes. Lasers have been applied for hard and soft tissue debridement, contouring as well as the bacterial load reduction in the pocket. Here we present a case report of chronic periodontitis treated with the help of a new technique, laser-assisted modified Widman flap (LAMWF). The surgical procedure followed with a 980 nm diode laser has been described. The present case report resulted in significant pocket depth reduction, attachment gain, and radiographic evidence of bone fill. The laser-assisted modified Widman flap provided excellent results without complications and high patient as well as clinician satisfaction.

Laser application in non-surgical periodontal therapy: a systematic review

OBJECTIVES

The primary aim was to address the following focused question: What is the clinical effect of laser application compared with mechanical debridement in non-surgical periodontal therapy in patients with chronic periodontitis? A secondary aim was to survey the relevant literature in relation to safety of laser applications.

MATERIAL AND METHODS

Electronic databases of the PubMed and the Cochrane Library were searched and completed by manual searches up to December 2007.

RESULTS

Following screening, 12 publications (11 studies) were eligible for the review. A meta-analysis could not be performed due to the heterogeneity of the studies. The results from a narrative synthesis indicate that Er:YAG laser monotherapy resulted in similar clinical outcomes, both in the short and the long term (up to 24 months), compared with mechanical debridement. There is insufficient evidence to support the clinical application of either CO(2), Nd:YAG, Nd:YAP, or different diode laser wavelengths.

CONCLUSIONS

The Er:YAG laser seems to possess characteristics most suitable for the non-surgical treatment of chronic periodontitis. Research conducted so far has indicated that its safety and effects might be expected to be within the range reported for conventional mechanical debridement. However, the evidence from the evaluated studies is weak.

Effect of the Diode Laser on Bacteremia Associated with Dental Ultrasonic Scaling: A Clinical and Microbiological Study

OBJECTIVE

The purpose of this study is to evaluate the potential use of diode lasers (DLs) to reduce bacteremia associated with ultrasonic scaling (US). Furthermore, the clinical efficacy of DLs as an adjunct to US in the treatment of gingivitis was investigated.

BACKGROUND DATA

Recently, lasers have found new applications in dental practice. The benefits of the use of DLs as an adjunct to US have not yet been determined.

METHODS

Twenty-two gingivitis patients were treated using a split-mouth study design in which each side was randomly treated by US alone or DL followed by US (DL + US). Blood samples were drawn just before and during US in each treatment step to detect induced bacteremia. Clinical parameters including plaque index, sulcus bleeding index, probing depth, and relative attachment level were recorded at baseline and 4 weeks postoperatively.

RESULTS

Bacteremia was detected in 15 patients (68%) after US alone, and in 8 patients following DL + US (36%). The reduction of the incidence of odontogenic bacteremia during US after the application of DL was statistically significant (p < 0.05). Clinical signs improved eventually, with no significant differences between the two treatment regimens (p > 0.05).

CONCLUSIONS

Application of DL energy can reduce bacteria in gingival crevices which may reduce bacteremia following US. The use of DL did not show additional clinical influence on gingival healing after treatment of gingivitis with US.

Effect of Er:YAG and Diode lasers on the adhesion of blood components and on the morphology of irradiated root surfaces

OBJECTIVE

The aim of this study was to evaluate in vitro, by scanning electron microscopy (SEM), the adhesion of blood components on root surfaces irradiated with Er:YAG (2.94 microm) and GaAlAs Diode (808 nm) lasers and the effects on the morphology of irradiated root surfaces.

METHODS

One hundred samples of human teeth were obtained. They were previously planed and scaled with manual instruments and divided into five groups of 20 samples each: G1 (control group) - absence of treatment; G2--Er:YAG laser (7.6 J/cm2); G3--Er:YAG laser (12.9 J/cm2); G4--Diode laser (90 J/cm2) and G5--Diode laser (108 J/cm2). After these treatments, 10 samples of each group received a blood tissue but the remaining 10 did not. After laboratory treatments, the samples were obtained by SEM, the photomicrographs were analysed by the score of adhesion of blood components and the results were statistically analysed (Kruskall-Wallis and Mann-Whitney test).

RESULTS

In relation to the adhesion of blood components, the study showed no significant differences between the control group and the groups treated with Er:YAG laser (p = 0.9633 and 0.6229). Diode laser radiation was less effective than control group and Er:YAG laser radiation (p < 0.01).

CONCLUSIONS

None of the proposed treatments increased the adhesion of blood components in a significant way when compared to the control group. Although the Er:YAG laser did not interfere in the adhesion of blood components, it caused more changes on the root surface, whereas the Diode laser inhibited the adhesion.

Effect of diode laser irradiation on the apical sealing of MTA retrofillings

Apical sealing is essential for the success of paraendodontic surgery, so any procedure that may favor an adequate sealing of the apical remainder should be performed. The purpose of this study was to evaluate the influence of diode laser irradiation on the apical sealing of root-end cavities with MTA retrofillings. Root canals in twenty extracted human teeth were shaped with K-files and filled with gutta-percha. The apexes were cut off and root-end preparations were performed. The roots were divided randomly in 2 groups. Group 1 (ten specimens) was retrofilled with MTA. Group 2 was irradiated with diode laser, with 1 W for 20 seconds, on the apical surface and root end cavity before retrofilling with MTA. The specimens had their external surfaces impermeabilized with cyanoacrylate, except for the apical surface, and were then immersed in 1% rhodamine B dye for 72 h and placed in plaster stone. After that, the specimens were submitted to longitudinal abrasion until half of the root remained. The linear dye leakage was observed in these mid-roots between the root canal wall and retrofilling. The linear dye leakage was measured with Image Lab software, and the results were statistically analyzed with Student's t test. There were no statistically significant differences between the two groups (p > 0.05). The diode laser irradiation did not improve the apical sealing of MTA retrofillings under the conditions of this in vitro study.

Histological evaluation of the use of diode laser as an adjunct to traditional periodontal treatment

OBJECTIVE

The aim of this study was to describe in vivo effects of scaling and root planing associated with 980-nm diode laser irradiation on periodontally diseased root surfaces.

BACKGROUND DATA

Rapid advances in the development of laser technologies used in dental offices demand careful evaluation of the respective histopathologic effects of each new system. There have been no reports of scaling and root planing associated with 980-nm diode laser effects on root surfaces after in vivo application.

METHODS

Single rooted teeth and multiple rooted teeth considered for extraction due to severe periodontal disease were included in the study. For light microscopic investigation, a resin-embedding technique was used to cut the undecalcified teeth into 30-microm-thick cross-sections and stained. The following parameters were recorded by a blind examiner: remaining debris, root surface morphology, and thermal side effects.

RESULTS

Root surfaces instrumented with hand instruments and diode laser in vivo did not show detectable surface alterations. There were no signs of thermal side effects in any of the teeth treated.

CONCLUSION

The present in vivo study showed that associated therapy was suitable for non-surgical periodontal treatment. The results suggest that the diode laser may be routinely used as an adjunct to scaling and root planing without damage to the cementum tissue.