COMPARISON OF CLINICAL EFFICIENCY OF DIODE LASER ASSISTED FLAP SURGERY WITH THAT OF CONVENTIONAL FLAP SURGERY.
BRIEF RESUME OF THE INTENDED WORK:
6.1 NEED FOR THE STUDY :
Periodontal therapy is directed at disease prevention, slowing or arresting disease progression, regeneration of lost periodontal tissues and maintaining the achieved therapeutic objectives. The primary goal in treating periodontitis is to remove bacterial deposits and halt the progression of disease. Complete removal of bacterial deposits and their toxins from the root surface is not always possible by conventional mechanical therapy because of limited access to areas such as furcations, concavities, developmental grooves and therefore such sites require surgical intervention.Longitudinal clinical trials of various conventional treatment techniques such as modified Widman flap and full thickness flap procedure with or without osseous recontouring have shown to be effective in treating moderate to advanced periodontitis. Thus flap surgery in deeper pockets results in greater immediate pocket reduction and attachment gain.1
The evolution of laser therapy for soft tissues manipulation and as an adjuvant in the management of infective aspects of periodontitis is progressing quite rapidly.2
Mechanical instrumentation of root surface for the reduction of bacteria and removal of soft and hard tissue deposits results in partial removal of pocket epithelium and healing by formation of a long junctional epithelium. Lasers used in this regard have shown to retard its downward growth.3A significant reduction of periodontopathogenic bacteria has been demonstrated, regardless of laser wavelength.4,5
Some of the lasers like CO2, Nd:YAG, Er:YAG, Er,Cr:YSGG and diode are used in soft tissue surgical procedures.6 Numerous articles dealing with laser treatment of periodontal tissues cover the usage of the Nd:YAG laser. The diode lasers has shown to have similar properties as the Nd:YAG laser that emits radiation within the infrared range at a very similar wavelength. The effect of laser irradiation on certain tissues depends on both wavelength of the laser and the absorbing capacity of the lased tissue. Although the Nd:YAG laser is similar to the diode laser, it leads to a temperature rise in markedly deeper tissue layers, whereas most of the diode laser irradiation is absorbed by superficial layers, thus having a better effect on sites affected by periodontal disease.7
Study assessing the periodontal ligament cell attachment to the root surface treated with 810nm diode laser has not shown any deleterious effect on root surface. Therefore diode laser can be safely used in periodontal pocket in close proximity of hard tissues.8
Studies using diode laser in animal models have shown adequate coagulation without damaging the surrounding tissues and also show an effect on new bone formation.9,10
There are no studies comparing conventional flap surgery with laser assisted flap surgery.Hence the present study is aimed to compare the clinical effectiveness of laser assisted flap surgery with that of conventional flap surgery.
6.2 REVIEW OF LITERATURE:
Twenty five patients were included in a study to evaluate and compare the longterm clinical outcomes of erbium-doped:yttrium, aluminum, garnet (Er:YAG) laser assisted periodontal flap surgery versus conventional treatment with the modified Widman flap procedure. In each patient left or right maxillary single rooted teeth were assigned randomly to one of two groups: group A (Er:YAG laser) and group B ( modified Widman flap surgery). Er:YAG laser was used to debride the bone pockets, scale the root surface, and trim the periodontal flap. Recession, probing depth, clinical attachment level, Plaque index, gingival index and bleeding on probing were recorded at baseline and at 3, 6, 12, 24, 36, 48 and 60 months. It was concluded that surgical treatment of single rooted teeth with chronic periodontitis using the Er:YAG laser yields greater pocket depth reduction and gains in clinical attachment level to conventional modified Widman flap surgery.1
A study was done to examine the removal of the epithelium in the periodontalpocket using a diode (980nm) laser in comparison with the conventional techniques in an animal experimental model. The buccal pockets of the posterior teeth in 10 freshly sacrificed adult pigs were scaled by three different examiners using conventional curettes. The lingual pockets were treated using a diode laser. The laser was used in a continuous wave mode with two different power settings of 2 and 4 watts with a 300µm – thick glass fibre. It was found that the laser with low power was able to remove the thin pocket epithelium while high power setting caused significant damage to the underlying connective tissues. The sites which were instrumented with the conventional curettes demonstrated significant epithelial remnants in all the tissues regardless of the level of periodontal surgical experience. Thus this study showed that instrumentation of the soft periodontal tissues with a diode laser (980nm) leads to a complete removal in comparison to conventional treatment methods with hand instruments.3
Another study examined the long term effects of diode laser therapy on periodontalpockets with regards to its bactericidal abilities and the improvement of periodontal condition. Fifty patients were randomly subdivided into two groups: laser group and control group. After evaluating periodontal indices which includes bleeding on probing and plaque index, patients oral hygiene instructions were given. Scaling was done in all patients. The deepest pockets of each quadrant of the laser group patients were microbiologically examined. All teeth were treated with diode laser. In control group hydrogen peroxide rinse was performed. The final values of the periodontal indices and further microbiological samples were measured after 6 months. It was found that bleeding on probing and bacterial count was reduced in diode laser group than in control group. Thus they concluded that the diode laser therapy in combination with scaling, supports healing of the periodontal pockets through elimination of bacteria.7
Another study was done to observe in vivo effects of two different power settingsof a Er:YAG laser on periodontally involved root surfaces using a scanning electron microscope(SEM). Thirty two teeth with severe periodontal disease scheduled for extraction were divided into three groups and irradiated at different energy levels of 140mJ/ 10 Hz and 160MJ/10Hz with the third group as control. They concluded that Er:YAG laser irradiation performed with two different power settings of root surfaces in vivo showed complete absence of debris and smooth root surfaces.11
A study was done to evaluate the histological changes in humans following a laser assisted new attachment procedure for the treatment of periodontal pockets. Six pairs of single –rooted teeth with moderate to advanced chronic periodontitis associated with sub gingival calculus deposits were treated. All teeth were scaled and root planed with ultrasonic and hand scalers. One of each pair of teeth received treatment of the inner pocket wall with free running pulsed neodymium:yttrium- aluminium – garnet (Nd:YAG) laser to remove the pocket epithelium and the test pockets were lased a second time to seal the pocket. All treated teeth were removed en-bloc for histologic processing after 3 months. LANAP treated teeth exhibited greater probing depths reductions and clinical probing attachment level gains than the control teeth. All LANAP treated specimens showed new cementum and new connective tissue attachment. Five of the six control teeth had a long junctional epithelium with no evidence of new attachment or regeneration. These cases support the concept that LANAP can be associated with cementum – mediated new connective tissue attachment and apparent periodontal regeneration of diseased root surfaces in humans.12
Twenty three patients were included in a study each of whom exhibited one deep intrabony defect. They were randomly treated with access flap surgery followed by root surface and defect debridement using an Er:YAG laser in test group and using hand and ultrasonic instruments in control group. Plaque index, gingival index, bleeding on probing, probing depth, gingival recession, and clinical attachment level were recorded at baseline and at 6 months. The test group displayed a higher tendency for CAL gain. It was concluded that at 6 months following treatment both therapies led to significant improvements of the clinical parameters and an Er:YAG laser may represent a suitable alternative for defect and root surface debridement in conjunction with periodontal surgery.13
6.3 AIMS AND OBJECTIVES OF THE STUDY:
1. To evaluate and compare the clinical outcomes of diode laser assisted flap surgery with conventional flap surgery.
2. To compare radiographic bone density changes between laser assisted flap surgery with conventional flap surgery.
MATERIALS AND METHODS :
7.1 SOURCE OF DATA
Patients visiting to the Department of Periodontology, RajaRajeswari Dental College and Hospital, Bangalore.
7.2METHOD OF COLLECTION OF DATA :
A total of 20 patients in the age group of 25 to 50 years, requiring periodontal flap surgery will be randomly selected.
Two quadrants from each patient will be randomly allotted to be treated using diode laser or with conventional flap surgery.
Group A - 20 quadrants will be treated using diode laser assisted flap surgery on one side.
Group B – 20 quadrants will be treated with conventional flap surgery on another side of same arch.
INCLUSION CRITERIA :
Systemically healthy patient
Probing pocket depth ≥6mm with more than 30% of sites involved.
Presence of at least ≥ 20 teeth
Plaque index < 1 after phase 1 treatment
Radiographic evidence of alveolar bone loss.
Patients on any medications taken within the last 6 months which may alter the periodontal status.
Pregnant and lactating mothers.
Patients who have undergone periodontal treatment within a period of 1 year.
Probing depth to be measured using graduated Williams periodontal probe from crest of gingival margin to base of the pocket.
Clinical attachment loss measured from CEJ to the base of the pocket.
Radio visio graphy of treated sites will be taken pre and post treatment at 3 and 6 months to measure bone density changes.
DURATION OF THE STUDY - 18 MONTHS
Consent will be obtained from each patient after explaining the nature of the treatment. All patients included for the study will undergo scaling and root planing and oral hygiene instructions will be given. Two quadrants in each patient will be selected in which one quadrant will be treated with laser assisted flap surgery and other quadrant with conventional flap surgery. The clinical parameters and data collection will be done at baseline and post treatment at 3 and 6 month intervals. Radiographic density changes will be assessed using Kodak Densitometric Software.
Following tests of statistics will be used in the present study,
1. Student t test – To compare the result between test and control group.
2. Wilcoxon Sign Rank Sum test – To compare the results between the various time intervals.
Any other statistical methods if required will be used.
7.3 DOES THE STUDY REQUIRE ANY INVESTIGATION OR INTERVENTION TO BE CONDUCTED ON PATIENTS OR OTHER HUMANS, ANIMALS? IF SO, PLEASE DESCRIBE BRIEFLY?
Yes. Patient will undergo periodontal flap surgery and radiographic evaluation pre and post treatment.
7.4 HAS ETHICAL CLEARANCE BEEN OBTAINED FROM YOUR INSTITUTION IN CASE OF 7.3 Yes. Ethical clearance certificate has been attached.
Boris G, Uros S.Clinical evaluation of periodontal surgical treatment with an Er:YAG Laser: 5-year results.J Periodontol2007;78:1864-1871.
Ajay M. Lasers in Periodontics-A Review. Eur J Dent Med 2011;3:1-11.
Geprge ER, Sarah B, Jurge W, George HN. Removal of epithelium in periodontal pockets following diode (980) nm laser application in the animal model: an vitro study. Photomed Lasers Surg 2004;22:177-183.
Cobb CM, McCawley TK, Killoy WJ. A preliminary study on the effects of the Nd:YAG laser on root surfaces and subgingival microflora in vivo. J Periodontol1992;63:701-707.
Coffelt DW, Cobb CM, MacNeil S, Rapley JW, Killoy WJ. Determination of energy density threshold for laser ablation of bacteria. An in vitro study. J Clin Periodontol 1997; 24:1-7.