In vivo and in vitro effects of an Er:YAG laser, a GaAlAs diode laser, and scaling and root planing on periodontally diseased root surfaces: a comparative histologic study

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.

The effect of erbium-doped: yttrium, aluminium and garnet laser irradiation on the surface microstructure and roughness of double acid-etched implants

Purpose

One of the most frequent complications related to dental implants is peri-implantitis, and the characteristics of implant surfaces are closely related to the progression and resolution of inflammation. Therefore, a technical modality that can effectively detoxify the implant surface without modification to the surface is needed. The purpose of this study was to evaluate the effect of erbium-doped: yttrium, aluminium and garnet (Er:YAG) laser irradiation on the microstructural changes in double acid-etched implant surfaces according to the laser energy and the application duration.

Methods

The implant surface was irradiated using an Er:YAG laser with different application energy levels (100 mJ/pulse, 140 mJ/pulse, and 180 mJ/pulse) and time periods (1 minute, 1.5 minutes, and 2 minutes). We then examined the change in surface roughness value and microstructure.

Results

In a scanning electron microscopy evaluation, the double acid-etched implant surface was not altered by Er:YAG laser irradiation under the condition of 100 mJ/pulse at 10 Hz for any of the irradiation times. However, we investigated the reduced sharpness of the specific ridge microstructure that resulted under the 140 mJ/pulse and 180 mJ/pulse conditions. The reduction in sharpness became more severe as laser energy and application duration increased. In the roughness measurement, the double acid-etched implants showed a low roughness value on the valley area before the laser irradiation. Under all experimental conditions, Er:YAG laser irradiation led to a minor decrease in surface roughness, which was not statistically significant.

Conclusions

The recommended application settings for Er:YAG laser irradiation on double acid-etched implant surface is less than a 100 mJ/pulse at 10 Hz, and for less than two minutes in order to detoxify the implant surface without causing surface modification.

Photodynamic therapy in the treatment of chronic periodontitis: a systematic review and meta-analysis

This meta-analysis was conducted to investigate the efficacy and safety of antimicrobial photodynamic therapy used alone or adjunctive to scaling root planing in patients with chronic periodontitis. The meta-analysis was conducted according to the QUOROM statement and recommendations of the Cochrane Collaboration. An extensive literature search was performed on seven databases, followed by a manual search. Weighted mean differences and 95% confidence intervals were calculated for clinical attachment level, probing depth and gingival recession. The I(2) test was used for inter-study heterogeneity; visual asymmetry inspection of the funnel plot, Egger's regression test and the trim-and-fill method were used to investigate publication bias. At 3 months, significant differences in clinical attachment level (p = 0.006) and probing depth reduction (p = 0.02) were observed for scaling root planing with antimicrobial photodynamic therapy, while no significant differences were retrieved for antimicrobial photodynamic therapy used alone; at 6 months no significant differences were observed for any investigated outcome. Neither heterogeneity nor publication bias was detected. The use of antimicrobial photodynamic therapy adjunctive to conventional treatment provides short-term benefits, but microbiological outcomes are contradictory. There is no evidence of effectiveness for the use of antimicrobial photodynamic therapy as alternative to scaling root planing. Long-term randomized controlled clinical trials reporting data on microbiological changes and costs are needed to support the long-term efficacy of adjunctive antimicrobial photodynamic therapy and the reliability of antimicrobial photodynamic therapy as alternative treatment to scaling root planing.

Effect of erbium-doped: yttrium, aluminium and garnet laser irradiation on the surface microstructure and roughness of sand-blasted, large grit, acid-etched implants

PURPOSE

The present study was performed to evaluate the effect of erbium-doped: yttrium, aluminium and garnet (Er:YAG) laser irradiation on sand-blasted, large grit, acid-etched (SLA) implant surface microstructure according to varying energy levels and application times of the laser.

METHODS

The implant surface was irradiated by the Er:YAG laser under combined conditions of 100, 140, or 180 mJ/pulse and an application time of 1 minute, 1.5 minutes, or 2 minutes. Scanning electron microscopy (SEM) was used to examine the surface roughness of the specimens.

RESULTS

All experimental conditions of Er:YAG laser irradiation, except the power setting of 100 mJ/pulse for 1 minute and 1.5 minutes, led to an alteration in the implant surface. SEM evaluation showed a decrease in the surface roughness of the implants. However, the difference was not statistically significant. Alterations of implant surfaces included meltdown and flattening. More extensive alterations were present with increasing laser energy and application time.

CONCLUSIONS

To ensure no damage to their surfaces, it is recommended that SLA implants be irradiated with an Er:YAG laser below 100 mJ/pulse and 1.5 minutes for detoxifying the implant surfaces.

Laser-induced fluorescence for subgingival calculus detection: scientific rational and clinical application in periodontology

OBJECTIVE

To review the data available on the laser-induced calculus fluorescence phenomenon and the calculus detection devices as well as to determine the clinical relevance of using commercialized calculus detection devices in periodontal treatment.

METHODS

In vitro or in vivo English publications found on Medline.

RESULTS

In vitro and in vivo studies showed that the devices on the market had a satisfactory detection capacity. Very few studies demonstrated that the erbium:yttrium-aluminium-garnet (Er:YAG) laser debridement, when performed with automatic calculus detection, could lead to improvements at the clinical level, and the outcome was similar to that obtained with conventional treatments.

CONCLUSIONS

Although preliminary data were encouraging, there was a lack of scientific data concerning the calculus detection devices. Therefore, future studies are crucial for determining the clinical relevance of such equipment.

Evaluation of the effectiveness of Er:YAG laser and conventional periodontal treatment in a patient with acute streptococcal gingivitis: a 2-year follow-up

OBJECTIVE

The aim of this study was to evaluate the effectiveness of Er:YAG laser and conventional periodontal therapy in the treatment of acute streptococcal gingivitis both clinically and microbiologically.

BACKGROUND DATA

This case report describes a 2-year follow-up of a 30-year-old, female, chronic periodontitis patient, presenting severe gingival inflammation, sensitivity, pain, and acute gingival lesions that were treated with Er:YAG laser and conventional hand and ultrasonic instruments.

MATERIALS AND METHODS

Before the initial periodontal treatment, microbiological samples were taken from the lesion sites with sterile paper points from the sulcuses bilaterally, and excisional biopsies were obtained from the lesions. Following diagnostic tests, the lesions were identified as acute streptococcal gingivitis. Following the measurement of clinical indices, initial periodontal therapy was performed with Er:YAG laser on the right side and conventional hand and ultrasonic instruments on the left side, which were performed as two sessions at weekly intervals. As an adjunct to mechanical periodontal therapy, 500 mg amoxicillin was prescribed t.i.d. for a week.

RESULTS

Microbiological samples grew mostly Streptococcus sp. and black pigmented obligate anaerobic bacteria. The histopathological examination revealed acanthosis, papillomatosis, and spongiotic lesions in the keratinized stratified squamous epithelium; infiltration of polymorphonuclear neutrophils, lymphocytes, and macrophages and plasma cells in the connective tissue; infiltration and accumulation of polymorphonuclear neutrophils in the epithelium, especially in the spongiotic lesions; and formation of microabscess-like clusters. After the initial periodontal treatment, clinical and microbiological measurements were repeated and reductions in clinical indices and the number of microorganisms were observed. both treatment modalities gave similar results, and no recurrences were observed during the 2-year follow-up.

CONCLUSION

Er:YAG laser seems to be promising and as effective as conventional periodontal therapy in the treatment of acute streptococcal gingivitis.

The effect of Er:YAG laser irradiation on the surface microstructure and roughness of hydroxyapatite-coated implant

Purpose

The present study was performed to evaluate the effect of erbium:yttrium-aluminium-garnet (Er:YAG) laser irradiation on the change of hydroxyapatite (HA)-coated implant surface microstructure according to the laser energy and the application time.

Methods

The implant surface was irradiated by Er:YAG laser under combination condition using the laser energy of 100 mJ/pulse, 140 mJ/pulse and 180 mJ/pulse and application time of 1 minute, 1.5 minutes and 2 minutes. The specimens were examined by surface roughness evaluation and scanning electron microscopic observation.

Results

In scanning electron microscope, HA-coated implant surface was not altered by Er:YAG laser irradiation under experimental condition on 100 mJ/pulse, 1 minute. Local areas with surface melting and cracks were founded on 100 mJ/pulse, 1.5 minutes and 2 minutes. One hundred forty mJ/pulse and 180 mJ/pulse group had surface melting and peeling area of HA particles, which condition was more severe depending on the increase of application time. Under all experimental condition, the difference of surface roughness value on implant surface was not statistically significant.

Conclusions

Er:YAG laser on HA-coated implant surface is recommended to be irradiated below 100 mJ/pulse, 1 minute for detoxification of implant surface without surface alteration.

Root surface biomodification with an Er:YAG laser for the treatment of gingival recession with subepithelial connective tissue grafts

BACKGROUND/AIM

Root surface biomodification has been used to treat gingival recession and periodontitis. The principle for this procedure is that removing the smear layer from the root surfaces exposes collagen fibers, which leads to improved healing. Clinical studies generally have failed to find any improvement in clinical parameters when using such agents. The aim of this study was to evaluate and compare the outcome of gingival recession therapy using the subepithelial connective tissue graft (SCTG) with or without Er:YAG laser application for root surface biomodification.

MATERIALS AND METHODS

Twenty-four teeth in 12 patients with Miller class I and II recession were treated with SCTG with (test group) or without (control group) the application of an Er:YAG laser (2 Hz, 60 mJ/pulse, 40 s, with air spray). Clinical attachment level (CAL), recession depth (RD), recession width (RW), and probing depth (PD) were measured at baseline and 6 months postsurgery.

RESULTS

There were no significant differences between test and control groups (p > 0.05). Postoperatively, significant root coverage, gains in CAL, and highly significant increases in the RW were observed in both groups. For test and control groups, the average root coverage was 80% and 86%, respectively (p > 0.05), and complete root coverage was 75% and 67%, respectively.

CONCLUSIONS

The present study showed that root surface conditioning with an Er:YAG laser does not enhance the results achieved when SCTG was performed alone.

Root surface biomodification with Nd:YAG laser for the treatment of gingival recession with subepithelial connective tissue grafts

BACKGROUND/AIM

Root surface biomodification has been used to treat gingival recession and periodontitis. The principle for this procedure is that removing the smear layer from the root surfaces exposes collagen fibers, which leads to improved healing. Clinical studies generally have failed to find any improvement in clinical parameters when using such procedures, however. The aim of this study was to evaluate and compare the outcome of gingival recession therapy using the subepithelial connective tissue graft (SCTG) with or without Nd:YAG laser application for root surface biomodification.

MATERIALS AND METHODS

Thirty-four teeth in 17 patients with Miller Class 1 and 2 recession were treated with SCTG with (test group) or without (control group) the application of Nd:YAG laser (1 W, 10 Hz, 100 mj, 60 s, 1064 nm). Clinical attachment level (CAL), recession depth (RD), recession width (RW), and probing depth (PD) were measured at baseline and six months postsurgery.

RESULTS

Both treatments yielded significant improvements in terms of RD and RW decrease and CAL gain compared to baseline values. For test and control groups, the average root coverage was 33% and 77%, respectively (p < 0.05), and the complete root coverage was 18% and 65%, respectively (p < 0.05). The control group showed a greater reduction in RD and RW compared with the test group (p < 0.05).

CONCLUSIONS

The use of Nd:YAG laser as a root surface biomodifier negatively affected the outcome of root coverage with the SCTG.

Lasers and the treatment of chronic periodontitis

For many intraoral soft-tissue surgical procedures the laser has become a desirable and dependable alternative to traditional scalpel surgery. However, the use of dental lasers in periodontal therapy is controversial. This article presents the current peer-reviewed evidence on the use of dental lasers for the treatment of chronic periodontitis.

Non-surgical periodontal therapy assisted by potassium-titanyl-phosphate laser: a pilot study

As the American Academy of Periodontology indicates, the treatment of chronic periodontitis should be achieved in the least invasive manner through non-surgical periodontal therapy. However, complete removal of subgingival plaque and calculus is hindered with increasing probing depth (PD) and furcation involvement using hand, sonic or ultrasonic instruments. Many authors have suggested that the use of laser as an adjunct to scaling and root planing (SRP) might improve the effectiveness of conventional periodontal treatment. The aim of this study was to evaluate potassium-titanyl-phosphate (KTP) laser in non-surgical periodontal therapy. Seven hundred and thirty sites with probing depths of 4-6 mm were involved in the study. The sites were divided into four groups: control (SRP, chlorhexidine gel 0.5%), group A (SRP, chlorhexidine gel 0.5%, three sessions of KTP laser irradiation); group B (SRP, three sessions of KTP laser irradiation) and group C (SRP, irrigation with povidone-iodine 10%, three sessions of KTP laser irradiation). KTP laser was used with the following parameters: output power 0.6 W, time on 10 ms, time off 50 ms, 30 s per irradiation, fluence 19 J/cm(2). All the sites showed improvement in all clinical parameters. Clinical attachment loss (CAL), pocket probing depths (PPDs) and bleeding on probing (BOP), especially in the lased groups, showed significant results (P < 0.001). Our experience showed KTP laser to be a significant help in SRP; nevertheless, more studies are necessary to confirm our results.

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.

Effects of Er:YAG laser compared to ultrasonic scaler in periodontal treatment: a 2-year follow-up split-mouth clinical study

BACKGROUND

The aim of this clinical study was to compare the results of non-surgical treatment of periodontal disease with an erbium-doped:yttrium, aluminum, and garnet (Er:YAG) laser to root debridement with an ultrasonic scaler.

METHODS

Twenty-five patients furnished two quadrants containing four teeth with probing depths (PD) >4 mm; the quadrants were divided equally between the right and left sides. On one side, teeth were treated by Er:YAG laser using 160 mJ/pulse at 10 Hz (test group); on the contralateral side, teeth were treated by ultrasonic scaler (control group). Clinical baseline data, including plaque index, gingival index, probing depth (PD), and clinical attachment level (CAL), were recorded before treatment and at 3 months and 1 and 2 years.

RESULTS

There were statistically significant differences in PD between the test and control groups for pockets of 1 to 4 mm (P <0.05), 5 to 6 mm (P <0.01), and > or =7 mm (P <0.001). However, there were no significant differences between the test and control groups for CAL gain in pockets of 1 to 4 mm; statistically significant differences were found between the test and control groups in pockets of 5 to 6 mm (P <0.01) and > or =7 mm (P <0.001).

CONCLUSION

Er:YAG laser periodontal treatment resulted in statistically significant improvements in PD and CAL gain compared to ultrasonic scaler treatment at 2-year follow-up, especially in moderate and deep pockets.

Immunohistochemical characterization of periodontal wound healing following nonsurgical treatment with fluorescence controlled Er:YAG laser radiation in dogs

BACKGROUND AND OBJECTIVE

The aim of the present study was to immunohistochemically characterize periodontal wound healing following nonsurgical treatment with fluorescence controlled Er:YAG laser radiation in dogs.

STUDY DESIGN/MATERIALS AND METHODS

Five beagle dogs suffering from naturally occurring chronic periodontitis were randomly allocated in a split-mouth design to nonsurgical periodontal treatment using either (a) an Er:YAG laser at 10.2, 12.8, 15.4, 18, and 20.4 J/cm2 (ERL1-5), or (b) an ultrasonic device (VUS) serving as control. The animals were sacrificed after 3 months. Histomorphometrical (e.g. inflammatory cell infiltrate, surface changes, cementum formation), and immunohistochemical parameters (collagen type I, CD68, matrix metalloproteinase (MMP)-8) were assessed.

RESULTS

Inflammatory cell infiltrates of different extent were commonly observed in all treatment groups. However, histomorphometrical analysis revealed new cementum formation with inserting collagen type I fibers along the instrumented root surfaces in most specimens of both ERL (ERL2: 31+/-81 to ERL5: 595+/-575 microm) and VUS (50+/- 215 microm) groups. This was associated with pronounced CD68 and weak MMP-8 antigen reactivity.

CONCLUSION

Within the limits of the present study, it was concluded that both treatment procedures (i) were effective in controlling inflammatory cell infiltrates, and (ii) may support the formation of a new connective tissue attachment.

Effect of Er:YAG Laser Combined With rhPDGF-BB on Attachment of Cultured Fibroblasts to Periodontally Involved Root Surfaces

BACKGROUND

The use of the erbium-doped:yttrium, aluminum, and garnet (Er:YAG) laser in periodontal therapy has been the focus of much research. Recombinant human platelet-derived growth factor-BB (rhPDGF-BB) is suggested as a potent stimulator and strong mitogen for human periodontal ligament cells. The present study tested the direct effects of Er:YAG laser irradiation, alone or with rhPDGF-BB application, on the biocompatibility of periodontally diseased roots through fibroblast attachment and proliferation.

METHODS

The study examined five healthy and 15 periodontally involved teeth, prepared from proximal surfaces, which were divided randomly into four groups (10 specimens each): group 1: healthy; group 2: untreated diseased; group 3: Er:YAG laser irradiation (60 mJ/pulse, 10 Hz); and group 4: Er:YAG laser irradiation (60 mJ/pulse, 10 Hz) plus rhPDGF-BB application (50 ng/ml). Three subgroups per group (three specimens each) were incubated for three periods (1, 3, or 7 days). The remaining specimen was used to determine surface topography. Fibroblasts were pooled on root specimens and incubated. Results were evaluated using scanning electron microscopy. Repeated cell counts were performed within a representative standard area.

RESULTS

Using paired t tests, all experimental groups (except group 2 diseased) showed statistically significant differences between 1- and 3-day and between 1- and 7-day incubation periods, but not between 3- and 7-day incubation periods. Using analysis of variance, the intergroup comparison showed significant differences favoring group 1 over groups 2 and 3 and group 4 over group 2 at the 1-day incubation period; group 1 was favored over groups 2, 3, and 4 and groups 3 and 4 were favored over group 2 at the 3- and 7-day incubation periods. Comparable effects were shown between groups 3 and 4 for all incubation periods and between groups 2 and 3 and groups 1 and 4 for the 1-day incubation.

CONCLUSIONS

Er:YAG laser used alone or in combination with rhPDGF-BB application may offer a promising periodontal therapy for conditioning root surfaces, although the combined application seemed to be slightly more effective. However, testing laser use in intervals and with parameters <60 mJ/pulse and 10 Hz is required to verify the minimum threshold values necessary to obtain complete root debridement and clarify optimal conditions for fibroblast cell attachment and growth. Further studies are needed to determine ideal parameters for creating the best environment for successful periodontal treatment.

Er:YAG laser therapy for peri-implant infection: a histological study

The purpose of this study was to evaluate the effects of Er:YAG laser on degranulation and implant surface debridement in peri-implant infection. The peri-implant infection was experimentally induced in dogs, and the treatment was performed using an Er:YAG laser or a plastic curet. Animals were sacrificed after 24 weeks, and undecalcified histological sections were prepared and analyzed. Degranulation and implant surface debridement were obtained effectively and safely by Er:YAG laser. Histologically, a favorable formation of new bone was observed on the laser-treated implant surface, and the laser group showed a tendency to produce greater bone-to-implant contact than the curet group. These results indicate that the Er:YAG laser therapy has promise in the treatment of peri-implantitis.

Influence of an Erbium, Chromium-Doped Yttrium, Scandium, Gallium, and Garnet (Er,Cr:YSGG) Laser on the Reestablishment of the Biocompatibility of Contaminated Titanium Implant Surfaces

BACKGROUND

The aim of the present study was to evaluate the influence of an erbium, chromium-doped yttrium, scandium, gallium, and garnet (Er,Cr:YSGG laser [ERCL]) on 1) the surface structure and biocompatibility of titanium implants and 2) the removal of plaque biofilms and reestablishment of the biocompatibility of contaminated titanium surfaces.

METHODS

Intraoral splints were used to collect an in vivo supragingival biofilm on sand-blasted and acid-etched titanium disks for 24 hours. ERCL was used at an energy output of 0.5, 1.0, 1.5, 2.0, and 2.5 W for the irradiation of 1) non-contaminated (20 and 25 Hz) and 2) plaque-contaminated (25 Hz) titanium disks. Unworn and untreated non-irradiated, sterile titanium disks served as untreated controls (UC). Specimens were incubated with SaOs-2 osteoblasts for 6 days. Treatment time, residual plaque biofilm (RPB) areas (%), mitochondrial cell activity (MA) (counts per second), and cell morphology/surface changes (scanning electron microscopy [SEM]) were assessed.

RESULTS

1) ERCL using either 0.5, 1.0, 1.5, 2.0, or 2.5 W at both 20 and 25 Hz resulted in comparable mean MA values as measured in the UC group. A monolayer of flattened SaOs-2 cells showing complete cytoplasmatic extensions and lamellopodia was observed in both ERCL and UC groups. 2) Mean RPB areas decreased significantly with increasing energy settings (53.8 +/- 2.2 at 0.5 W to 9.8 +/- 6.2 at 2.5 W). However, mean MA values were significantly higher in the UC group.

CONCLUSION

Within the limits of the present study, it was concluded that even though ERCL exhibited a high efficiency to remove plaque biofilms in an energy-dependent manner, it failed to reestablish the biocompatibility of contaminated titanium surfaces.

Nonsurgical treatment of moderate and advanced periimplantitis lesions: a controlled clinical study

The aim of this controlled, parallel design clinical study was to evaluate the effectiveness of an Er:YAG (erbium-doped:yttrium, aluminum, and garnet) laser for nonsurgical treatment of periimplantitis lesions. Twenty patients, each of whom displayed at least one implant with (a) moderate and (b) advanced periimplantitis (n=40 implants; IMZ, ITI, Spline Twist, ZL-Duraplant, Camlog), were randomly instrumented nonsurgically using either (1) an Er:YAG laser (100 mJ/pulse, 10 Hz) device (LAS) or (2) mechanical debridement using plastic curettes and antiseptic therapy with chlorhexidine digluconate (0.2%) (C). The following clinical parameters were measured at baseline, 3, 6, and 12 months after treatment: plaque index, bleeding on probing (BOP), probing depth, gingival recession, and clinical attachment level (CAL). Mean BOP improved significantly in both groups at 3, 6, and 12 months (a- lesions: P<0.001 and b- lesions: P<0.01, respectively). After 3 and 6 months, the mean reduction of BOP was significantly higher in the LAS group when compared to the C group (a- and b- lesions: P<0.01 and P<0.05, respectively). At 3 and 6 months, both groups revealed significant CAL gains at a- and b- lesions (P<0.01, respectively). In both groups, however, the mean CAL at a- and b- lesions was not significantly different from the respective baseline values at 12 months (P>0.05, respectively). Although treatment of periimplantitis lesions with LAS resulted in a significantly higher BOP reduction than C, its effectiveness seemed to be limited to a period of 6 months, particularly at b- lesions.

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.

Lasers in periodontics: a review of the literature

BACKGROUND

Despite the large number of publications, there is still controversy among clinicians regarding the application of dental lasers to the treatment of chronic periodontitis. The purpose of this review is to analyze the peer-reviewed research literature to determine the state of the science concerning the application of lasers to common oral soft tissue problems, root surface detoxification, and the treatment of chronic periodontitis.

METHODS

A comprehensive computer-based search combined the following databases into one search: Medline, Current Contents, and the Cumulated Index of Nursing and Allied Health. This search also used key words. In addition, hand searches were done for several journals not cataloged in the databases, and the reference lists from published articles were checked. All articles were considered individually to eliminate non-peer-reviewed articles, those dealing with commercial laser technology, and those considered by the author to be purely opinion articles, leaving 278 possible articles.

RESULTS

There is a considerable conflict in results for both laboratory studies and clinical trials, even when using the same laser wavelength. A meaningful comparison between various clinical studies or between laser and conventional therapy is difficult at best and likely impossible at the present. Reasons for this dilemma are several, such as different laser wavelengths; wide variations in laser parameters; insufficient reporting of parameters that, in turn, does not allow calculation of energy density; differences in experimental design, lack of proper controls, and differences in severity of disease and treatment protocols; and measurement of different clinical endpoints.

CONCLUSIONS

Based on this review of the literature, there is a great need to develop an evidence-based approach to the use of lasers for the treatment of chronic periodontitis. Simply put, there is insufficient evidence to suggest that any specific wavelength of laser is superior to the traditional modalities of therapy. Current evidence does suggest that use of the Nd:YAG or Er:YAG wavelengths for treatment of chronic periodontitis may be equivalent to scaling and root planing (SRP) with respect to reduction in probing depth and subgingival bacterial populations. However, if gain in clinical attachment level is considered the gold standard for non-surgical periodontal therapy, then the evidence supporting laser-mediated periodontal treatment over traditional therapy is minimal at best. Lastly, there is limited evidence suggesting that lasers used in an adjunctive capacity to SRP may provide some additional benefit.

Application of DIAGNOdent® as a guide for removing carious dentin with Er:YAG laser

OBJECTIVES

The purpose of this study was to investigate the DIAGNOdent values applicable as a guide for removal of outer layer of carious dentin with Er:YAG laser.

METHODS

Carious dentin of human extracted molars was removed by bur with Caries Detector (Group 1: red stained dentin was left, Group 2: light pink stained dentin was left) and by Er:YAG laser with DIAGNOdent value as a guide (30>Group 3>21, 20>Group 4>11, 10>Group 5). The cavity floor dentin after removing carious dentin was examined using microradiograms, EPMA and SEM.

RESULTS

The cavity floor dentin of group 1,3 showed the decreases in the degree of X-ray absorption. In group 2,4 and 5, decrease of Ca, P were not observed. The decrease of Mg was observed on the more superficial part of the cavity floor for group 3 than for group 4.

CONCLUSIONS

When carious dentin was removed using Er:YAG laser, the carious dentin outer layer was ideally removed with DIAGNOdent values: 11-20. DIAGNOdent values: 11-20, could indicate the completion of outer layer removal of carious dentin with Er:YAG laser, but there are some problems that must be addressed before the clinical application.

Influence of fluorescence-controlled Er:YAG laser radiation, the Vectortm system and hand instruments on periodontally diseased root surfaces in vivo

OBJECTIVES

The aim of the present study was to evaluate the effects of fluorescence-controlled Er:YAG laser radiation, an ultrasonic device or hand instruments on periodontally diseased root surfaces in vivo.

MATERIAL AND METHODS

Seventy-two single-rooted teeth (n=12 patients) were randomly treated in vivo by a single course of subgingival instrumentation using (1-3) an Er:YAG laser (ERL1: 100 mJ; ERL2: 120 mJ; ERL3: 140 mJ; 10 Hz), or (4) the Vector ultrasonic system (VUS) or (5) hand instruments (SRP). Untreated teeth served as control (UC). Areas of residual subgingival calculus (RSC) and depth of root surface alterations were assessed histo-/morphometrically.

RESULTS

Highest values of RSC areas (%) were observed in the SRP group (12.5+/-6.9). ERL(1-3) (7.8+/-5.8, 8.6+/-4.5, 6.2+/-3.9, respectively) revealed significantly lower RSC areas than SRP. VUS (2.4+/-1.8) exhibited significantly lower RSC areas than SRP and ERL(1, 2). Specimens treated with SRP revealed conspicuous root surface damage, while specimens treated with ERL(1-3) and VUS exhibited a homogeneous and smooth appearance.

CONCLUSION

Within the limits of the present study, it may be concluded that ERL and VUS enabled (i) a more effective removal of subgingival calculus and (ii) a predictable root surface preservation in comparison with SRP.

Clinical and histological healing pattern of peri-implantitis lesions following non-surgical treatment with an Er:YAG laser

BACKGROUND AND OBJECTIVES

The aim of the present study was to assess clinical and histo-pathological healing pattern of peri-implantitis lesions following non-surgical treatment with an Er:YAG laser (ERL).

STUDY DESIGN/MATERIALS AND METHODS

Twelve patients suffering from peri-implantitis (n = 12 implants) received a single episode of non-surgical instrumentation using ERL (12.7 J/cm2). Assessment of clinical parameters (plaque index (PI), bleeding on probing (BOP), probing pocket depth, gingival recession (GR), and clinical attachment level (CAL)), surgical defect examination, and histo-pathological examination of peri-implant tissue biopsies was performed after 1, 3, 6, 9, 12, and 24 months.

RESULTS

All patients exhibited improvements of all clinical parameters investigated. However, histo-pathological examination of tissue biopsies revealed a mixed chronic inflammatory cell infiltrate (macrophages, lymphocytes, and plasma cells) which seemed to be encapsulated by deposition of irregular bundles of fibrous connective tissue showing increased proliferation of vascular structures.

CONCLUSION

It was concluded that a single course of non-surgical treatment of peri-implantitis using ERL may not be sufficient for the maintenance of failing implants.

Periodontal tissue healing following flap surgery using an Er:YAG laser in dogs

BACKGROUND AND OBJECTIVES

The purpose of this study was to compare periodontal tissue healing following flap surgery using an Er:YAG laser with that of conventional surgery.

STUDY DESIGN/MATERIALS AND METHODS

Bilateral premolars with experimentally induced periodontitis in six dogs were treated by periodontal flap surgery. Degranulation and root debridement in the furcation were performed using an Er:YAG laser or curet. At 3 months postsurgery, animals were sacrificed and decalcified specimens were prepared for histological and histometric analysis.

RESULTS

Degranulation and root debridement were effectively performed with an Er:YAG laser without major thermal damage and significantly faster than with a curet. Histologically, the amount of newly formed bone was significantly greater in the laser group than in the curet group, although both groups showed similar amounts of cementum formation and connective tissue attachment.

CONCLUSIONS

The Er:YAG laser irradiation can be safely and effectively utilized in periodontal flap surgery, and has the potential to promote new bone formation.

Influence of different treatment approaches on the removal of early plaque biofilms and the viability of SAOS2 osteoblasts grown on titanium implants

The aim of the present study was to evaluate the influence of different treatment approaches on: (1) the removal of early plaque biofilms grown on titanium implants, and (2) the biocompatibility of the instrumented implant surfaces. Five volunteers wore acrylic splints with sand-blasted and acid-etched titanium discs for 24 h to build up supragingival plaque. A total of 80 specimens were randomly assigned to the following groups: (1) an Er:YAG laser (100 mJ/pulse, 10 Hz) (Y), (2) an ultrasonic system (U), (3) plastic curettes and rinsing with chlorhexidine digluconate (P), or (4) unworn titanium discs (C). Autoclaved specimens were incubated with SAOS2 cells for three days. The following parameters were measured: treatment time (T), residual plaque biofilm (RPB) and clean implant surface (CIS) areas (%), and mitochondrial cell activity (MA) (counts/s). Statistical analysis within and between groups revealed the following mean scores (+/-SD): RPB areas: P (61.1+/-11.4)>U (36.8+/-4.5)>Y (5.8+/-5.1); CIS areas: Y (94.2+/-5.1)>U (63.2+/-4.5)>P (38.9+/-11.2); T: Y (5.6+/-1.2)>U (2.4+/-0.5)>P (2.3+/-0.5); MA: C (1.528.636+/-188.371)>U (831.594+/-370.228)>Y (678.250+/-367.902)>P (144.105+/-120.961). Within the limits of the present study, it may be concluded that Y seems to be most suitable for the removal of supragingival early plaque biofilms grown on SLA titanium implants, and (2) all treatment procedures failed to restore the biocompatibility of previously-contaminated SLA titanium surfaces.

Clinical efficacy of semiconductor laser application as an adjunct to conventional scaling and root planing

BACKGROUND AND OBJECTIVES

The aim of the in vitro study was to examine the clinical efficacy of semiconductor laser periodontal pocket irradiation as an adjunct to conventional scaling and root planing.

MATERIALS AND METHODS

Twenty-two healthy patients with a need of periodontal treatment (15 women, 7 men, mean age 45.0 +/- 10.8 years) with at least four teeth in all quadrants, were included. All of them underwent a conventional periodontal treatment including scaling and root planing. Using a split mouth design, two randomly chosen quadrants (one upper and the corresponding lower one) were subsequently treated with an 809 nm GaAlAs laser operated at a power output of 1.0 Watt using a 0.6 mm optical fiber. The teeth in the control quadrants were rinsed with saline. The clinical outcome was evaluated by means of plaque index (PI), gingival index (GI), bleeding on probing (BOP), sulcus fluid flow rate (SFFR), Periotest (PT), probing pocket depth (PPD), and clinical attachment loss (CAL) at baseline and at 3 months after treatment. A total of 492 teeth in both groups were evaluated and differences between the laser and the control teeth were analyzed using the Wilcoxon test (P < 0.05).

RESULTS

Teeth treated with the laser revealed a significantly higher reduction in tooth mobility, pocket depth, and clinical attachment loss. Twelve percent of the teeth in the laser group showed an attachment gain of 3 mm or more, compared to 7% in the control group. An attachment gain of 2-3 mm was found in 24% of the teeth in the laser group and 18% in the control group. No significant group differences, however, could be detected for the plaque index, gingival index, bleeding on probing, and the sulcus fluid flow rate.

CONCLUSIONS

The higher reduction in tooth mobility and probing depths is probably not predominantly related to bacterial reduction in the periodontal pockets but to the de-epithelization of the periodontal pockets leading to an enhanced connective tissue attachment. The application of the diode laser in the treatment of inflammatory periodontitis at the irradiation parameters described above is a safe clinical procedure and can be recommended as an adjunct to conventional scaling and root planing.

The biologic rationale for the use of lasers in dentistry

Dentists have a variety of wavelengths to choose from when purchasing a laser. Each wavelength has a unique interaction with the target tissues of the oral cavity. This article gives a rationale, grounded in sound biologic principles, for the use of different wavelengths in the oral cavity. Advantages and disadvantages of the various wavelengths for specific procedures are discussed.

Healing of intrabony defects following surgical treatment with or without an Er:YAG laser

AIM

The aim of this controlled, parallel design clinical study was to compare the healing of intrabony periodontal defects following treatment with access flap surgery with and without debridement with an Er:YAG laser.

METHODS

Twenty-three patients each of whom exhibited one deep intrabony defect were randomly treated with either access flap surgery followed by root surface and defect debridement using an Er:YAG laser (KEY3) (160 mJ, 10 Hz) (test), or with access flap surgery followed by root surface and defect debridement using hand and ultrasonic instruments (control). The following clinical parameters were recorded at baseline and at 6 months: plaque index; gingival index; bleeding on probing; probing depth (PD); gingival recession; and clinical attachment level (CAL). The primary outcome variable was CAL. No statistically significant differences between the groups were found at baseline.

RESULTS

No serious adverse events were observed after any of the treatments. The results have shown that in the test group the PD decreased from 7.8+/-1.3 to 4.1+/-1.3 mm (p<0.001) and the CAL changed from 9.8+/-2.9 to 7.2+/-2.5 mm (p<0.001). In the control group the PD decreased from 7.8+/-0.8 to 4.6+/-1.6 mm (p<0.001) and the CAL changed from 9.2+/-1.2 to 7.7+/-1.6 mm (p<0.01). The test group displayed a higher tendency for CAL gain, although this tendency did not prove to be statistically significant.

CONCLUSION

Within the limits of the present study, it can be concluded that: (i) at 6 months following treatment both therapies led to significant improvements of the investigated clinical parameters, and (ii) an Er:YAG laser may represent a suitable alternative for defect and root surface debridement in conjunction with periodontal surgery.