Australian Dental Journal

Australian Dental Journal The official journal of the Australian Dental Association SCIENTIFIC ARTICLE Australian Dental Journal 2013; 58: 41 49 doi: 10.1111/adj.12021 Comparison of periodontal open flap debridement versus closed debridement with Er,Cr:YSGG laser M Gupta,* AK Lamba,* M Verma, F Faraz,* S Tandon,* K Chawla,* DK Koli *Department of Periodontics, Maulana Azad Institute of Dental Sciences, New Delhi, India. Department of Prosthodontics, Maulana Azad Institute of Dental Sciences, New Delhi, India. ABSTRACT Background: Traditional periodontal open flap debridement (OFD) results in reduced pocket depth (PD), clinical attachment loss (CAL), gingival recession (GR) and postoperative pain and discomfort. The quest to overcome these shortcomings has led to research into Er,Cr:YSGG laser assisted pocket therapy (ELAPT). This study was designed to compare the clinical outcomes of ELAPT versus OFD. Methods: Fifteen patients with a PD of 5 mm and 8 mm at two sites were selected. Test sites (Group 1) were treated by ELAPT and the control (Group 2) by OFD. Clinical parameters were recorded at baseline, 3 and 6 months and included Plaque Index (PI), Gingival Index (GI), modified Sulcular Bleeding Index (msbi), PD, CAL and GR. Results: Both treatments produced a reduction in PI, GI, msbi and PD, an increase in GR, and a gain in CAL at 3 and 6 months. The mean gain of CAL in Group 1 at 3 and 6 months (1.60 0.78 and 1.80 0.63) was similar (p > 0.05) to the value of Group 2 (1.93 0.88 and 2.00 0.54). GR increased significantly (p < 0.05) only in Group 2 at 3 and 6 months (1.80 0.56 and 1.87 0.64) compared to Group 1 (0.50 0.68 and 0.60 0.74). Conclusions: ELAPT compared with OFD results in similar CAL gains with less GR and significant reductions in PD, GI and msbi, and may be considered as an alternative to surgical therapy. Keywords: Er,Cr:YSGG laser, open flap debridement, periodontitis, non-surgical. Abbreviations and acronyms: CAL = clinical attachment loss; ELAPT = Er,Cr:YSGG laser assisted pocket therapy; GI = Gingival Index; GR = gingival recession; OFD = open flap debridement; PD = pocket depth; PI = Plaque Index. (Accepted for publication 23 May 2012.) INTRODUCTION Periodontal therapy is directed at disease prevention, slowing or arresting disease progression, regeneration of lost periodontal tissues, and maintaining the achieved therapeutic objectives. 1,2 A variety of techniques have been used for periodontal therapy, e.g. scaling and root planing, subgingival curettage, gingivectomy and full or split thickness flap procedures with or without osseous recontouring. 1,3,4 Traditional periodontal surgery results in reduced pocket depth due to apical repositioning of the gingival margin, exposing the root surface to the oral cavity. It results in possible attachment loss, gingival cratering and gingival recession. 5 The pain and discomfort associated with periodontal surgery is also well known. 6 The quest to overcome these shortcomings has led to research into laser assisted periodontal therapy. Different lasers, e.g. the diode, Nd:YAG, CO 2, Er: YAG and Er,Cr:YSGG have been proposed and are expected to serve as an alternative or an adjunctive treatment to conventional, mechanical periodontal therapy. 7,8 Laser periodontal therapy is predicated on the concept of subgingival curettage and/or reattachment and regeneration of the attachment apparatus and is commonly referred to as non-surgical. 7 It allows for selective removal of sulcular or pocket epithelium while preserving connective fibrous tissues. 9 It defines the tissue margins, preserves the integrity of the mucosa and aids in maintaining the free gingival crest. 9 High patient comfort and acceptance has been reported with laser periodontal therapy. 9 With thin and flexible fibres, laser device energy can be delivered to sites in the periodontal pocket that conventional mechanical instrumentation is unable to reach. 10 Laser periodontal therapy eliminates pockets with minimal recession or repositioning of the gingival 2013 Australian Dental Association 41

M Gupta et al. margin. 10 Other advantages include haemostasis, less postoperative swelling, a reduction in bacterial population at the surgical site, less need for suturing, faster healing and less postoperative pain. 11 Laser systems such as CO 2, diode and Nd:YAG have been used for oral soft tissue procedures such as gingivectomies, frenectomies, etc. 12 Due to an excellent soft tissue ablation capacity, CO 2 lasers have been successfully used as an adjunctive tool to de-epithelialize the mucoperiosteal flap during traditional flap surgery. 13 Diode and Nd:YAG lasers have been used mainly for laser-assisted subgingival curettage and disinfection of the periodontal pocket with various degrees of success. 13 However with these lasers, a profound thermal effect on target tissues including gingival tissue, periodontal ligament, cementum and bone has been seen and their use for periodontal application does not appear promising. 14 The potential use of Er,Cr:YSGG laser as a tool for the non-surgical debridement of pathological periodontal pockets is related to its capacity to ablate soft tissue with minimal thermal side effects. 15 Because the Er,Cr: YSGG laser has a wavelength close to the peak of absorption coefficient of water, absorption of the energy by water occurs rapidly, resulting in evaporation of water, microexplosive ablation and reduced heat accumulation. 15 It also possesses bactericidal effects because of the high coefficient of absorption of the used light frequency by lipopolysaccharides. 15 It has also been shown to have a significant bactericidal effect on both P. gingivalis and A. actinomycetemcomitans, which are primary components of periodontal infection. 15 Er,Cr:YSGG laser irradiation can be safely and effectively utilized in periodontal pocket therapy, and has the potential to promote new attachment. 15 It has been claimed in the literature that the Er,Cr:YSGG laser system provides a more comfortable patient experience with less trauma and postoperative complications, as well as a decreased healing time 16 compared to conventional flap surgery. Therefore, the purpose of this study was to evaluate and compare the clinical outcomes of Er,Cr:YSGG laser-assisted periodontal pocket therapy versus open flap debridement procedure. MATERIALS AND METHODS The study was designed as a single-blinded, splitmouth, randomized and controlled trial of 6-month duration. The study protocol was reviewed and approved by the Ethics Committee of the Maulana Azad Institute of Dental Sciences (Delhi University), New Delhi. The study was conducted in accordance with the Helsinki Declaration of 1975, as revised in 2000, and all participants signed informed consent forms. Fifteen patients between the age of 20 and 54 years of either gender having a probing depth of 5 mmat a minimum of two sites were selected from the Periodontics Outpatient Department, Maulana Azad Institute of Dental Sciences, New Delhi, India. The subjects were selected randomly with no discrimination of gender, caste, religion or socio-economic status. Inclusion criteria were residual presence of probing depth of 5 mm and 8 mm at a minimum of two sites and good level of oral hygiene (PI <1) after initial therapy. Patients were excluded from participation in the study if they presented with diabetes, coronary heart disease, chronic obstructive pulmonary disease, tobacco use, or the use of antibiotics in the previous 6 months. On one side, teeth were treated by Er,Cr:YSGG laser (ELAPT; test group), whereas teeth of the contralateral side were treated by open flap debridement (OFD; control group). In the control group (OFD), the area to undergo surgery was anaesthetized with 2% lignocaine hydrochloride solution with adrenaline (1:80 000). Intracrevicular incisions were placed. The granulation tissue was removed from the defects and the roots were thoroughly scaled and planed. No root surface conditioning was performed. The control sites were then sutured with simple interrupted sutures. (Fig. 1). For Er,Cr:YSGG laser assisted periodontal pocket therapy (ELAPT; test group) no local anaesthesia was given. 13,15 If required, the pocket to be treated was lightly irrigated with 2% lignocaine hydrochloride solution with adrenaline (1:80 000). 15 The patient and all operatory personnel were made to wear protective laser eyewear. The following settings were used for ELAPT: power 1W, water 10%, air 12% and frequency 20 Hz. A 600 μ sapphire laser tip (9 mm length) was used and inserted into the sulcus to the base of the pocket. The laser tip was then withdrawn 1 mm from the base and activated. The tip was moved apico-coronally (vertically) and mesio-distally (horizontally) in sweeping motions in the pocket. The tip was angled so that the energy was directed parallel to the root and towards the inner epithelial lining of the sulcus. The tip was kept constantly moving inside the pocket. The objective was to remove the epithelial lining of the pocket. Each pocket was lased for 60 seconds. Following lasing of the pocket, any visible deposits on the root surfaces were removed using hand and ultrasonic instruments. The area was then irrigated with sterile saline. The gingival tissue was compressed against the root surface to close the pocket and to aid in the formation and stabilization of fibrin clot. No sutures or periodontal dressings were given (Fig. 2). A second and third cycle of lasing was repeated with similar settings every third day. This was 42 2013 Australian Dental Association

Open flap debridement versus laser (a) (b) (c) (d) Fig. 1 Open flap debridement. (a) pre-operative; (b) intra-operative; (c) postoperative 3 months; (d) postoperative 6 months. (a) (b) (c) (d) Fig. 2 Laser assisted periodontal pocket therapy. (a) pre-operative; (b) intra-operative; (c) postoperative 3 months; (d) postoperative 6 months. attempted with the consideration of delaying epithelial downgrowth and promoting regeneration of periodontal tissues. Postoperatively no antibiotics or analgesics were prescribed. Patients were instructed to discontinue toothbrushing for the day of the treatment, avoiding trauma at the treated site. A 60-second rinse with 10 ml of 0.2% chlorhexidine gluconate solution twice daily for 1 week was prescribed. Data collection The baseline data were recorded before treatment and at 3 months and 6 months following treatment. The data collection was performed by the same blinded and calibrated investigator. Clinical measurements were taken at six points around each tooth: mesio-lingual, mesio-facial, facial, disto-facial, disto-lingual and lingual. 2013 Australian Dental Association 43

M Gupta et al. The following clinical parameters were measured: Plaque Index (PI), Gingival Index (GI), Probing Depth (PD), Clinical Attachment Level (CAL), Gingival Recession (GR) and modified Sulcular Bleeding Index (msbi). PD was determined with a calibrated conventional periodontal probe. Intra-examiner reliability Four patients, each with two contralateral teeth with PD >5 mm, were used to calibrate the examiner. The examiner evaluated the patients at two appointments that were separated by 5 days. Calibration was accepted if the data at baseline and 5 days later were similar at a >90% level. This procedure was repeated periodically during the 6-month study period. Statistical analysis A software package was used for the statistical analysis [SPSS (Statistical Package for Social Sciences) Version 16]. The unpaired t-test was used for comparison of mean values between the LASER and OFD groups, and ANOVA test was used for comparison of mean values within the LASER and OFD groups at the different intervals. The level of significance was taken at 5% (p < 0.05). The alpha error was set at 0.05. Data are presented as means SD. The power of the study, given 1 mm as a significant difference between groups, was calculated to be 0.99. RESULTS The comparison of mean values of each parameter between the LASER and OFD group at baseline was done and there were no statistically significant differences (p > 0.05) between the two treatment groups in any of the recorded parameters (Table 1). Probing depth The mean PD at baseline was 6.93 1.03,at3months 4.87 1.25 and at 6 months 4.47 0.92 among the laser treatment group. The mean PD at baseline was 6.93 0.70, at 3 months 3.33 0.62 and at 6 months 3.13 0.74 among the OFD group. The comparison of Table 1. Comparison of mean values of PD, CAL, GR, GI, PI and msbi at baseline LASER OFD p-value PD (mm) 6.93 1.03 6.93 0.70 0.332 CAL (mm) 7.93 1.16 8.13 0.83 0.708 GR (mm) 1.00 0.65 1.07 0.59 0.135 GI 1.50 0.28 1.65 0.31 0.178 PI 0.77 0.22 0.80 0.23 0.818 msbi 1.22 0.31 1.27 0.35 0.681 mean PD at baseline, 3 months and 6 months for both the laser treatment group and the OFD group was found to be statistically significant (p < 0.05) (Table 2). The mean PD reduction at 3 months was found to be 2.66 0.88 among the laser treatment group and 3.60 0.70 among the OFD group. The mean PD reduction at 6 months was found to be 2.46 0.62 among the laser treatment group and 3.80 0.80 among the OFD group. The comparison of mean PD reduction at 3 months and 6 months between the laser treatment and OFD was found to be statistically significant (p < 0.05) (Table 3). This implies that although the PD decreased significantly in both treatment groups compared to baseline, OFD was more effective in reduction of PD compared to laser assisted pocket therapy at both 3 and 6 months post-treatment intervals. Clinical attachment level The mean CAL at baseline was 7.93 1.16, at 3 months 6.33 1.35 and at 6 months 6.13 1.19 Table 2. Comparison of mean values of PD at baseline, 3 months and 6 months Intervals Probing depth (mm) LASER (μ r) OFD (μ r) 1 Baseline 6.93 1.03 6.93 0.70 2 3 months 4.87 1.25 3.33 0.62 3 6 months 4.47 0.92 3.13 0.74 p-value 0.000* 0.000* Post hoc comparison 1 > 2, 3 1 > 2, 3 *- S. Table 3. Comparison of mean change in PD, CAL, GR, GI, PI and msbi Parameter LASER OFD p-value PD reduction at 3 months (mm) PD reduction at 6 months (mm) CAL gain at 3 months (mm) CAL gain at 6 months (mm) GR increase at 3 months (mm) GR increase at 6 months (mm) GI score reduction at 3 months GI score reduction at 6 months PI score reduction at 3 months PI score reduction at 6 months msbi score reduction at 3 months msbi score reduction at 6 months 2.06 0.88 3.60 0.70 0.000* 2.46 0.62 3.80 0.80 0.000* 1.60 0.78 1.93 0.88 0.122 1.80 0.63 2.00 0.54 0.269 0.53 0.68 1.80 0.56 0.000* 0.60 0.74 1.87 0.64 0.000* 0.55 0.24 0.95 0.24 0.000* 0.52 0.26 0.95 0.24 0.000* 0.17 0.18 0.20 0.27 0.726 0.08 0.20 0.17 0.21 0.388 0.52 0.31 0.78 0.30 0.022* 0.53 0.28 0.85 0.28 0.005* 44 2013 Australian Dental Association

Open flap debridement versus laser among the laser treatment group. The mean CAL at baseline was 8.13 0.83, at 3 months 6.20 0.94 and at 6 months 6.13 0.83 among the OFD group. The comparison of mean CAL at baseline, 3 months and 6 months for the laser treatment and OFD group was found to be statistically significant (p < 0.05) (Table 4). The mean CAL gain at 3 months was found to be 1.60 0.78 among the laser treatment group and 1.93 0.88 among the OFD group. The mean CAL gain at 6 months was found to be 1.80 0.63 among the laser treatment group and 2.00 0.54 among the OFD group. The comparison of mean CAL gain at 3 months and 6 months between the laser treatment and OFD was found to be statistically not significant (p > 0.05) (Table 3). This implies that there was significant gain in CAL in both treatment groups compared to baseline, and laser assisted pocket therapy was equally effective in producing CAL gain compared to OFD at both 3 and 6 month post-treatment intervals. Gingival recession The mean GR at baseline was 1.00 0.65, at 3 months 1.53 0.92 and at 6 months 1.60 0.99 among the laser treatment group. The mean GR at baseline was 1.07 0.59, at 3 months 2.87 0.74 and at 6 months 2.93 0.80 among the OFD group. The comparison of mean GR at baseline, 3 months and 6 months for the laser treatment group was found to be statistically not significant (p > 0.05) but for the OFD group was found to be statistically significant (p < 0.05) (Table 5). Table 4. Comparison of mean values of CAL at baseline, 3 months and 6 months Intervals Clinical Attachment Level (mm) LASER (μ r) OFD (μ r) 1 Baseline 7.93 1.16 8.13 0.83 2 3 months 6.33 1.35 6.20 0.94 3 6 months 6.13 1.19 6.13 0.83 p-value 0.000* 0.000* Post hoc comparison 1 > 2, 3 1 > 2, 3 Table 5. Comparison of mean values of GR at baseline, 3 months and 6 months Intervals Gingival recession (mm) LASER (μ r) OFD (μ r) 1 Baseline 1.00 0.65 1.07 0.59 2 3 months 1.53 0.92 2.87 0.74 3 6 months 1.60 0.99 2.93 0.80 p-value 0.063 0.000* Post-hoc comparison - 1 > 2, 3 The mean increase in GR at 3 months was found to be 0.53 0.68 among the laser treatment group and 1.80 0.56 among the OFD group. The mean increase in GR at 6 months was found to be 0.60 0.74 among the laser treatment group and 1.87 0.64 among the OFD group. The comparison of mean increase in GR at 3 months and 6 months between the laser treatment and OFD was found to be statistically significant (p < 0.05) (Table 3). This implies that sites treated with laser assisted pocket therapy show significantly less GR when compared to sites treated with OFD. Gingival Index The mean reduction in GI score at 3 months was found to be 0.55 0.24 among the laser treatment group and 0.95 0.24 among the OFD group. The mean reduction in GI score at 6 months was found to be 0.52 0.26 among the laser treatment group and 0.95 0.24 among the OFD group. The comparison of mean reduction in GI scores at 3 months and 6 months between the laser treatment group and the OFD group was found to be statistically significant (p < 0.05) (Table 3). This implies that although the GI decreased significantly in both treatment groups compared to baseline, OFD was more effective in reduction of GI compared to laser assisted pocket therapy at both 3 and 6 month post-treatment intervals. Plaque Index The comparison of mean reduction in PI score at 3 months and 6 months between the laser treatment group and the OFD group was found to be statistically not significant (p > 0.05) (Table 3). This implies that the relatively low baseline values for PI in both treatment groups did not change significantly over the 6 months of the study and yielded no statistical difference between the groups. Modified Sulcular Bleeding Index The mean reduction in msbi score at 3 months was found to be 0.52 0.31 among the laser treatment group and 0.78 0.30 among the OFD group. The mean reduction in msbi score at 6 months was found to be 0.53 0.28 among the laser treatment group and 0.85 0.28 among the OFD group. The comparison of mean reduction in msbi score at 3 months and 6 months between the laser treatment group and the OFD group was found to be statistically significant (p < 0.05) (Table 3). This implies that although the msbi decreased significantly in both treatment groups compared to 2013 Australian Dental Association 45

M Gupta et al. baseline, OFD was more effective in reduction of msbi compared to laser assisted pocket therapy at both 3 and 6 month post-treatment intervals. DISCUSSION With the discovery of lasers and research into their applicability for dental use, laser energy has emerged as a newer modality of therapy in the field of periodontics. 13 Laser energy is capable of ablating and vaporizing residual organic debris, including microbial plaque and probably calculus, and it can disinfect and remove the pocket s sulcular lining. 13 Adjunctive therapy with laser energy, aimed at reducing or eliminating bacteria may be useful in reducing probing depth and bleeding on probing. 7,8,13 Nonsurgical laser pocket therapy offers several advantages over conventional surgical procedures such as minimal bleeding, instant sterilization of the surgical site, reduced bacteraemia, reduced mechanical trauma, minimal postoperative swelling and scarring, and minimal postoperative pain. 7,17,18 It can be associated with cementum-mediated new connective tissue attachment and apparent periodontal regeneration on previously diseased root surfaces. 8 The ideal properties of a laser that can be used successfully for periodontal pocket therapy are that it should be bactericidal, easy to deliver into the pocket and safe enough to use in a periodontal pocket so that it causes no harm to the root surface. Current literature identifies erbium lasers (Er:YAG and Er,Cr:YSGG) as the most appropriate device for non-surgical periodontal treatment due to their high absorption in water and lack of thermal penetration. 8,19 Also, as the interaction between the erbium laser wavelength and gingival tissues is shallow in depth (0.1 0.3 mm), it results in less wound contraction and a reduced inflammatory response. 19 Studies have shown that the erbium laser can remove epithelium effectively without damaging the underlying connective tissue. Furthermore, in an animal study the erbium laser has been seen to induce new cementum formation after pocket irradiation. 20 According to Kaldahl et al., 5 Schwarz et al. 21 and Sculean et al. 17 smokers have a less favourable response to non-surgical and surgical periodontal therapy. Therefore, smokers were excluded from the study. Patients who had poorly controlled diabetes were also excluded from the study as, according to Derdilopoulou et al. 22 and Gaspirc, 1 diabetics have increased microbial challenge and delayed wound healing which could influence the outcome of the therapy. The defect sites were selected in patients using clinical criteria similar to studies of Miyazaki et al. 23 and Tomasi et al. 18 All patients were subjected to initial preparation which consisted of full mouth scaling and root planing as this allows for optimal tissue health and plaque control, thereby enhancing treatment outcomes. All measurements were taken with a manual calibrated UNC-15 periodontal probe which had colour coding at 5, 10, 15 mm with markings 0 to 15, each marking at 1 mm intervals, making it easier to reproduce the measurement. Before treatment, a customized acrylic stent was fabricated on the study cast for each patient. The stent was grooved in an occlusal apical direction. This was done to minimize change in the direction of probing at subsequent recordings. All these measurements were made from a fixed reference point on the stent, in accordance with the study by Miyazaki et al. 23 For the test site, laser assisted pocket therapy was performed without the application of local anaesthesia as, according to Sj ostr om and Friskopp, 24 pain experience during laser therapy for periodontal procedures is negligible and does not require the use of anaesthetics and results in diminished bleeding. The settings used for ELAPT were in accordance with the suggested clinical specifications by BIOLASE Technology. The calibration for the initial therapy with laser tip was done at 1 mm less than the pocket probing depth of the treatment site as this measurement allows for the laser energy to penetrate the tissue and reduce the bacterial load without the fibre touching the epithelial attachment at the bottom of the pocket. 15 After completion of the laser assisted pocket therapy no sutures or periodontal dressing were given. Postoperatively, no antibiotics and analgesics were prescribed. A second and third cycle of lasing was done at every third day in an attempt to delay epithelial downgrowth and promote periodontal tissue regeneration as, according to Goldman et al., 25 during the healing phase, migration of the epithelium begins from the existing epithelium of attached gingiva and new epithelium begins to cover the exposed gingival corium within 2 to 3 days. Furthermore, formation and organization of connective tissue fibres takes place during healing and these fibers, although somewhat immature in arrangement and width, appear well organized in about 10 14 days. 25 In light of this, lasing wasn t done beyond three cycles to prevent any inadvertent damage to the healing connective tissue fibres within the pocket. Also, the sulcus heals from the bottom up and hence during the second and third lasing, the tip was placed 2 mm less than the pocket probing depth of the treatment site to allow healing at the floor of the pocket. 26,27 The postoperative instructions and recalls were in accordance with studies by Schwarz et al., 7 Sculean et al., 17 Raffetto 15 and Gaspirc. 1 Reprobing treatment sites were not attempted before 3 months as tissue reattachment to the root surface could be damaged with a probe, delaying the healing process. 26,27 46 2013 Australian Dental Association

Open flap debridement versus laser For the control site, open flap debridement was performed and the soft tissue flap was repositioned at the original level and closed with simple interrupted sutures using 3 0 silk to obtain primary soft tissue closure. The control site was then covered with periodontal dressing. According to Nasr et al., 28 periodontal dressing prevents the impingement of foreign materials into the control site and also minimizes flap displacement which would jeopardize the success of the treatment. Patients were given both verbal and written instructions. Antibiotics were prescribed to all patients after open flap debridement. According to Kornman et al., 29 antibiotics provide clinical benefits during the postoperative phase of periodontal surgery as bacterial contamination adversely affects the clinical outcome of treatment. Patients were given pain medication to avoid discomfort after the effect of anaesthesia wore off. Patients were instructed to use 0.2% chlorhexidine gluconate mouthwash twice daily for 4 weeks. According to Newman et al. 30 and Addy, 31 chlorhexidine helps in reducing the bacterial load in the oral cavity and prevents the accumulation of plaque. At the baseline examination, there were no statistically significant differences between the two treatment groups in any of the recorded parameters. Both treatments produced a reduction in PI, GI, msbi and PD, an increase in GR, and a gain in CAL at 3 and 6 month post-treatment intervals. In both treatment groups, the PD decreased significantly compared to baseline (p < 0.05). However, the mean PD reduction at 3 and 6 months was significantly greater (p < 0.05) for the OFD sites than for sites treated with laser assisted pocket therapy. As a primary outcome variable, significant gain in CAL was recorded compared to baseline in both the treatment groups (p < 0.05). The mean gain of CAL in the laser treatment group at 3 and 6 months was similar to the value of the control group (p > 0.05). Gingival recession increased significantly only in the OFD group compared to baseline (p < 0.05). The mean GR at 3 and 6 months was significantly lower (p < 0.05) for the laser treatment sites. GI decreased significantly in both groups post-treatment at 3 and 6 months (p < 0.05). However, OFD was significantly effective (p < 0.05) in reduction of GI as compared to laser assisted pocket therapy at both 3 and 6 months post-treatment intervals. Also, the msbi scores for both treatment groups reduced significantly after treatment (p < 0.05), although the OFD group exhibited a significantly lower msbi score at 3 and 6 months postoperatively compared to the laser treatment group (p < 0.05). The results obtained in the present study with OFD in terms of reduction in PD and gain in CALs confirm those reported by Lindhe et al., 32 Pihlstrom et al., 33 Isidor and Karring, 34 and Sculean et al. 17 For the laser assisted pocket therapy, the reduction in PD and gain in CAL values are consistent with those of Watanabe et al., 35 Schwarz et al., 7,21 Sculean et al., 17 Tomasi et al., 18 and Gaspirc and Skaleric. 1 The changes seen with laser therapy may be attributed to the fact that due to the laser s ablating action, the epithelium lining the soft tissue wall of the pocket and the adjacent inflammatory cell infiltrate may have been removed. In addition, the low dose radiation that scatters into the surrounding tissues may possess a beneficial effect on the healing process. 8,35 Also, erbium laser therapy might have resulted in improved proliferation of fibroblasts and their adhesion to root surfaces leading to CAL gain. 7 Results from similar studies with Er:YAG have also indicated that due to the minimally invasive nature of laser treatment, trauma to hard and soft tissues is minimal, causing less GR. 7,21 There is less collagen remodelling, faster healing and minimal scar tissue with laser assisted pocket therapy which might explain why less GR takes place. Erbium lasers have antimicrobial effects and detoxification properties. They have a high bactericidal potential against periodontopathic bacteria. 36,37 The lack of microbial data in the study does not allow us to correlate the levels of microbiota in baseline pockets and in residual pockets after the surgery with clinical parameters at different time periods in study. However, a clinical indicator of inflammation, bleeding on probing (msbi and GI scores) roughly reflects the level of periodontal pathogens in the pocket. 38,39 So it can be hypothesized that the reduction in GI and msbi scores might be due to a bactericidal and detoxification effect of the laser. The results of the present study showed significant differences between the OFD and laser assisted pocket therapy treated sites with regard to reduction in PD, mean increase in GR, improvement in GI and msbi scores. However, both sites demonstrated similar improvements in terms of gain in CAL. The greater pocket depth reduction in the case of OFD may also be attributed to the higher amount of GR seen postoperatively and it can be assumed that although significant difference was found in terms of PD reduction in favour of OFD but the change was at the cost of recession. It was also observed that laser assisted pocket therapy was far less invasive and less time consuming than OFD, and required almost no use of analgesia increasing patient compliance. This treatment modality had no postoperative complications or impaired clinical healing, indicating that this type of laser treatment may not have any detrimental effect when employed for pocket therapy. Within the constraints of this study, it can be concluded that the use of an Er,Cr:YSGG laser in the non-surgical treatment of periodontal pockets can result in similar CAL gains to that of OFD with much 2013 Australian Dental Association 47

M Gupta et al. less recession and can also result in statistically significant reductions in PD, GI and msbi. It may be considered as an alternative to the surgical therapy for pockets ranging from 5 to 8 mm, especially in the anterior zone of the oral cavity where aesthetics play a key role. In addition, laser assisted pocket therapy seems to possess additional benefits in terms of having no need of analgesia, less mechanical trauma, instant sterilization of the treated site, less postoperative complications (swelling and pain), no need of antibiotics as well as analgesics postoperatively, a minimally invasive procedure with greater patient compliance and less time consuming with minimal bleeding. However, OFD showed significantly better results compared to laser assisted pocket therapy in terms of PD reduction, GI score and msbi score improvements. Also, true periodontal regeneration can only be evaluated histologically and it is recommended that further longitudinal clinical trials be conducted to analyse the maximum potential of lasers in non-surgical as well as surgical periodontal therapy. REFERENCES 1. Gaspirc B, Skaleric U. Clinical evaluation of periodontal surgical treatment with an Er:YAG laser: 5-year results. J Periodontol 2007;78:1864 1871. 2. Cobb CM. Clinical significance of non-surgical periodontal therapy: an evidence-based perspective of scaling and root planing. J Clin Periodontol 2002;29(Suppl 2):6 16. 3. Ramfjord SP, Nissle RR. The modified Widman flap. J Periodontol 1974;45:601 607. 4. Ramfjord SP. Present status of the modified Widman flap procedure. J Periodontol 1977;48:558 565. 5. Kaldahl WB, Kalkwarf KL, Patil KD, Dyer JK, Bates RE Jr. Evaluation of four modalities of periodontal therapy. Mean probing depth, probing attachment level and recession changes. J Periodontol 1988;59:783 793. 6. Curtis JW Jr, McLain JB, Hutchinson RA. The incidence and severity of complications and pain following periodontal surgery. J Periodontol 1985;56:597 601. 7. Schwarz F, Sculean A, Berakdar M, Georg T, Reich E, Becker J. Clinical evaluation of an Er:YAG laser combined with scaling and root planing for non-surgical periodontal treatment. A controlled, prospective clinical study. J Clin Periodontol 2003;30: 26 34. 8. Aoki A, Sasaki KM, Watanabe H, Ishikawa I. Lasers in nonsurgical periodontal therapy. Periodontol 2000 2004;36:59 97. 9. Gold SI, Vilardi MA. Pulsed laser beam effects on gingiva. J Clin Periodontol 1994;21:391 396. 10. Crespi R, Barone A, Covani U. Histologic evaluation of three methods of periodontal root surface treatment in humans. J Periodontol 2005;76:476 481. 11. Moritz A, Schoop U, Goharkhay K, et al. Treatment of periodontal pockets with a diode laser. Lasers Surg Med 1998;22:302 11. 12. Pick RM, Colvard MD. Current status of lasers in soft tissue dental surgery. J Periodontol 1993;64:589 602. 13. Sculean A, Schwarz F, Berakdar M, Windisch P, Arweiler NB, Romanos GE. Healing of intrabony defects following surgical treatment with or without an Er:YAG laser. A pilot study. J Clin Periodontol 2004;31:604 608. 14. Dean DB. Concepts in laser periodontal therapy using the Er, Cr:YSGG laser. The Academy of Dental Therapeutics and Stomatology. 15. Raffetto N. Lasers for initial periodontal therapy. Dent Clin North Am 2004;48:923 936. 16. Wang X, Zhang C, Matsumoto K. In vivo study of the healing processes that occur in the jaws of rabbits following perforation by an Er,Cr:YSGG laser. Lasers Med Sci 2005;20:21 27. 17. Sculean A, Schwarz F, Berakdar M, Romanos GE, Arweiler NB, Becker J. Periodontal treatment with an Er:YAG laser compared to ultrasonic instrumentation: a pilot study. J Periodontol 2004;75:966 973. 18. Tomasi C, Schander K, Dahlen G, Wennstr om JL. Short-term clinical and microbiologic effects of pocket debridement with an Er:YAG laser during periodontal maintenance. J Periodontol 2006;77:111 118. 19. Rotundo R, Nieri M, Cairo F, et al. Lack of adjunctive benefit of Er:YAG laser in non-surgical periodontal treatment: a randomized split-mouth clinical trial. J Clin Periodontol 2010;37:526 533. 20. Schwarz F, Jepsen S, Herten M, Aoki A, Sculean A, Becker J. Immunohistochemical characterization of periodontal wound healing following nonsurgical treatment with fluorescence controlled Er:YAG laser radiation in dogs. Lasers Surg Med 2007;39:428 440. 21. Schwarz F, P utz N, Georg T, Reich E. Effect of an Er:YAG laser on periodontally involved root surfaces: an in vivo and in vitro SEM comparison. Lasers Surg Med 2001;29:328 335. 22. Derdilopoulou FV, Nonhoff J, Neumann K, Kielbassa AM. Microbiological findings after periodontal therapy using curettes, Er:YAG laser, sonic, and ultrasonic scalers. J Clin Periodontol 2007;34:588 598. 23. Miyazaki A, Yamaguchi T, Nishikata J, et al. Effects of Nd: YAG and CO2 laser treatment and ultrasonic scaling on periodontal pockets of chronic periodontitis patients. J Periodontol 2003;74:175 180. 24. Sjostrom L, Friskopp J. Laser treatment as an adjunct to debridement of periodontal pockets. Swed Dent J 2002;26:51 57. 25. Goldman HM, Cohen DW. Periodontal therapy. 6th edn. St Louis: CV Mosby, 1980:640 754. 26. Rooney M, Midda M, Leeming J. A laboratory investigation of the bactericidal effect of an Nd:YAG laser. Br Dent J 1994;176:61 64. 27. Whitters CJ, MacGarlane TW, McKenzie D, et al. The bacterial activity of pulsed Nd:YAG laser radiation in vitro. Lasers Med Sci 1994;9:2979 3303. 28. Nasr HF, Aichelmann-Reidy ME, Yukna RA. Bone and bone substitutes. Periodontol 2000 1999;19:74 86. 29. Kornman KS, Robertson PB. Fundamental principles affecting the outcomes of therapy for osseous lesions. Periodontol 2000 2000;22:22 43. 30. Newman MG, Sanz M, Nachnani S, Saltini C, Anderson L. Effect of 0.12% chlorhexidine on bacterial recolonization following periodontal surgery. J Periodontol 1989;60:577 581. 31. Addy M. The use of antiseptics in periodontal therapy. In: Lindhe J, Karring T, Long NP, eds. Clinical Periodontology and Implant Dentistry. 4th edn. Blackwell Munksgaard, 2003:480. 32. Lindhe J, Westfelt E, Nyman S, Socransky SS, Heijl L, Bratthall G. Healing following surgical/non-surgical treatment of periodontal disease. A clinical study. J Clin Periodontol 1982;9:115 128. 33. Pihlstrom BL, Oliphant TH, McHugh RB. Molar and nonmolar teeth compared over 6½ years following two methods of periodontal therapy. J Periodontol 1984;55:499 504. 34. Isidor F, Karring T. Long-term effect of surgical and non-surgical periodontal treatment. A 5-year clinical study. J Periodontal Res 1986;21:462 472. 48 2013 Australian Dental Association

Open flap debridement versus laser 35. Watanabe H, Ishikawa I, Suzuki M, Hasegawa K. Clinical assessments of the erbium:yag laser for soft tissue surgery and scaling. J Clin Laser Med Surg 1996;14:67 75. 36. Ando Y, Aoki A, Watanabe H, Ishikawa I. Bactericidal effect of erbium YAG laser on periodontopathic bacteria. Lasers Surg Med 1996;19:190 200. 37. Folwaczny M, Mehl A, Aggstaller H, Hickel R. Antimicrobial effects of 2.94 microm Er:YAG laser radiation on root surfaces: an in vitro study. J Clin Periodontol 2002;29:73 78. 38. Armitage GC, Dickinson WR, Jenderseck RS, Levine SM, Chambers DW. Relationship between the percentage of subgingival spirochetes and the severity of periodontal disease. J Periodontol 1982;53:550 556. 39. Greenstein G. The role of bleeding upon probing in the diagnosis of periodontal disease. A literature review. J Periodontol 1984;55:684 688. Address for correspondence: Dr Manak Gupta 124 Defence Enclave Vikas Marg New Delhi-110092 India Email: manak.gupta@gmail.com 2013 Australian Dental Association 49