Lasers in nonsurgical periodontal therapy

Short-term clinical and microbiologic effects of pocket debridement with an Er:YAG laser during periodontal maintenance

BACKGROUND

The erbium-doped:yttrium, aluminum, and garnet (Er:YAG) laser is considered a useful tool for subgingival debridement because the laser treatment creates minimal damage to the root surface and has potential antimicrobial effects. The aim of this randomized controlled clinical trial was to evaluate clinical and microbiologic effects of pocket debridement using an Er:YAG laser in patients during periodontal maintenance.

METHODS

Twenty patients at a recall visit for maintenance were consecutively recruited if presenting at least four teeth with residual probing depth (PD) > or = 5 mm. Two pockets in each of two jaw quadrants were randomly assigned to subgingival debridement using 1) an Er:YAG laser (test) or 2) an ultrasonic scaler (control). The laser beam was set at 160 mJ with a pulse frequency of 10 Hz. Clinical variables were recorded at baseline, 1 month, and 4 months after treatment. Primary clinical outcome variables were changes in PD and clinical attachment level (CAL). Microbiologic analysis of subgingival samples was performed at baseline, 2 days, and 30 days after treatment using a checkerboard DNA-DNA hybridization technique against 12 periodontal disease-associated species.

RESULTS

The mean initial PD was 6.0 mm (SD: 1.2) in the test group and 5.8 mm (SD: 0.9) in the control group. At 1 month post-treatment, the PD reduction was significantly greater for test than control sites (0.9 versus 0.5 mm; P <0.05). The CAL gain also was significantly greater (0.5 versus 0.06 mm; P <0.01). At the 4-month examination, no significant differences were detected in PD reduction (1.1 versus 1.0 mm) or CAL gain (0.6 versus 0.4 mm). Both treatments resulted in reduction of the subgingival microflora. No significant differences in microbiologic composition were identified between the treatment groups at various time intervals. Degree of treatment discomfort scored significantly lower for the test than the control treatment modality.

CONCLUSION

The results of the trial failed to demonstrate any apparent advantage of using an Er:YAG laser for subgingival debridement, except less treatment discomfort perceived by the patients.

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.

Assessing microleakage of class V resin composite restorations after Er:YAG laser and bur preparation

BACKGROUND AND OBJECTIVE

This study aimed to evaluate the extent of microleakage in cavities prepared with bur and Er:YAG laser, hybridized with different bonding systems.

STUDY DESIGN

Sixty bovine teeth were randomly divided into six groups (n = 10): (G1) Diamond bur + Single Bond; (G2) Diamond bur + AdheSE; (G3) Diamond bur + Clearfil SE Bond; (G4) Er:YAG (250 mJ, 4 Hz, 80.6 J/cm(2)) + Single Bond; (G5)Er:YAG + AdheSE, and (G6) Er:YAG + Clearfil. Cavities were restored with a micro-hybrid composite resin. After thermocycling, the specimens were stained with 2% methylene blue solution and sectioned in the mesiodistal direction. Dye penetration was scored based upon the extent of the dye using a light stereoscope.

RESULTS

The Kruskal-Wallis and Mann-Whitney test revealed no statistically significant differences between the method of preparation (diamond bur and laser). However, statistical differences were found between the adhesives tested.

CONCLUSION

Based on the results of this study, Er:YAG laser confirmed to be as effective as the conventional methods for preparing adhesive restorations.

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.

Nonsurgical approaches for the treatment of periodontal diseases

This article reviews nonsurgical approaches for the management of periodontal diseases. A brief review of the pathogenesis of periodontitis allows the reader to identify the potential points of intervention. Assessment of risk factors for periodontitis and the potential for risk reduction are introduced as the first part of a three-pronged approach to therapy. Antimicrobial approaches, including the use of mechanical therapy, antiseptics, and antibiotics,are described next. Host modulatory therapy is addressed as the fi-nal component of the nonsurgical approach to periodontal therapy. Clinical applications of these nonsurgical options are presented as part of the treatment strategy.

Comparison of jaw-opening reflexes evoked by Er:YAG laser versus scalpel incisions in rats

OBJECTIVE

Anecdotal remarks suggest that incisions in oral soft tissue would be less painful if performed with laser rather than with scalpel, but such an argument remains to be scientifically validated.

STUDY DESIGN

Twelve rats received graded incisions to lip, gingiva, mucosa, and tongue with either a pulsed Er:YAG laser (65 mJ/pulse at 10 Hz) or a stainless steel scalpel. The amplitude of the jaw-opening reflex, as measured by the digastric muscle electromyogram, was used to quantify the nociceptive response evoked by the surgical incisions.

RESULTS

Except for lip, mean reflex amplitudes evoked by laser were significantly smaller (P < .05) than those evoked by scalpel in all other incision sites.

CONCLUSION

Er:YAG laser surgery may be less painful and therefore require less use of anesthesia and sedation than conventional scalpel surgery in oral soft tissue procedures.