ORIGINAL ARTICLE

Non-surgical periodontal therapy assistedby potassium–titanyl–phosphate laser: a pilot study

Umberto Romeo & Gaspare Palaia & Ricciarda Botti &Valentina Leone & Jean-Paul Rocca & Antonella Polimeni

Received: 24 May 2009 /Accepted: 7 October 2009 /Published online: 21 November 2009# Springer-Verlag London Ltd 2009

Abstract As the American Academy of Periodontologyindicates, the treatment of chronic periodontitis should beachieved in the least invasive manner through non-surgical periodontal therapy. However, complete removalof subgingival plaque and calculus is hindered withincreasing probing depth (PD) and furcation involvementusing hand, sonic or ultrasonic instruments. Manyauthors have suggested that the use of laser as anadjunct to scaling and root planing (SRP) might improvethe 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 dividedinto four groups: control (SRP, chlorhexidine gel 0.5%),group A (SRP, chlorhexidine gel 0.5%, three sessions ofKTP laser irradiation); group B (SRP, three sessions ofKTP laser irradiation) and group C (SRP, irrigation withpovidone-iodine 10%, three sessions of KTP laser

irradiation). KTP laser was used with the followingparameters: output power 0.6 W, time on 10 ms, time off50 ms, 30 s per irradiation, fluence 19 J/cm2. All the sitesshowed improvement in all clinical parameters. Clinicalattachment loss (CAL), pocket probing depths (PPDs) andbleeding on probing (BOP), especially in the lased groups,showed significant results (P<0.001). Our experienceshowed KTP laser to be a significant help in SRP;nevertheless, more studies are necessary to confirm ourresults.

Keywords Chronic periodontitis . Periodontal pockets .

Potassium–titanyl–phosphate (KTP) laser

Introduction

Periodontal disease is a multifactorial inflammatory diseaseof the supporting tissues of the teeth that leads to theprogressive destruction of the periodontal ligament andalveolar bone, with pocket formation, recession or both.

Chronic periodontitis is initiated by the accumulation ofmicrobial plaque and calculus and generally has a slow tomoderate rate of progression, but periods of more rapiddestruction may be observed. The extent and severity ofdamage varies among individuals and over time. Thisvariation in disease expression is the result of theinteraction of the host’s genetics, and environmental andmicrobial factors [1]. Local factors may influence plaqueaccumulation: systemic diseases such as diabetes mellitusmay influence the host defences; environmental factorssuch as cigarette smoking and stress may also influence theresponse of the host to plaque accumulation [2].

The treatment guidelines of the American Academy ofPeriodontology stress that periodontal health should be

U. Romeo :G. Palaia :R. Botti :V. Leone :A. PolimeniDepartment of Dental Sciences, School of Dentistry,Sapienza University of Rome,Rome, Italy

J.-P. RoccaLaser Technology and Oral Environment Laboratory, UFRO,University of Nice,Nice, France

J.-P. RoccaCentre Hospitalier Universitaire de Nice (CHU St Roch),Nice, France

U. Romeo (*)Via Della Brianza 13,00162 Rome, Italye-mail: umberto.romeo@uniroma1.it

Lasers Med Sci (2010) 25:891–899DOI 10.1007/s10103-009-0738-4

achieved in the least invasive and most cost-effectivemanner [3]. This is often accomplished through non-surgical periodontal treatment.

Complete removal of biofilm and mineralized depositsfrom the tooth surface, reinforcement of the patient’s oralhygiene practices and regular follow-up to eliminate newdeposits are the main goals of non-surgical periodontaltherapy. Conventional techniques used for scaling androot planing are hand instrumentation, sonic and ultra-sonic instrumentation, and the use of antimicrobialagents. Hand instruments, and sonic and ultrasonicscalers, recommended for subgingival scaling, have beenshown to be effective in removing plaque and calculusfrom root surfaces in vivo, thereby reducing the bacterialload in periodontal pockets. In addition, an antimicrobialeffect of ultrasonic treatment against non-periodontopathicbacteria has been demonstrated in vitro [4].

However, complete removal of subgingival plaque andcalculus is hindered with increasing periodontal probingdepth (PPD) and furcation involvement using hand, sonicor ultrasonic instruments, because it is doubtful whetherthey can reach the root surfaces. Thus, regardless of theinstrument of choice, interproximal areas, furcas andmulti-rooted teeth are most likely to exhibit residualplaque and calculus following treatment, and surgerymay be indicated to restore periodontal anatomydamaged by periodontal diseases and to facilitate oralhygiene practices [4, 5]. For these reasons, different localor systemic antibiotic regimens have been advocated inthe treatment of periodontitis.

Among the locally administered adjunctive antimicro-bials, the most beneficial results were observed fortetracycline, minocycline, metronidazole and chlorhexi-dine. However, for the treatment of chronic periodontitis,the marginal additional improvements in PPD andattachment level are a fraction of the improvement fromscaling and root planing (SRP) alone [6]. Furthermore,these agents are difficult to maintain at a therapeuticconcentration in the periodontal pocket, and there isincreased concern regarding the development of antibioticresistance [7].

Because of this aspect, the use of laser radiation withinthe periodontal pocket has become a topic of much interestand is a promising field in periodontal therapy. As laserscan achieve excellent tissue ablation, with strong bacteri-cidal and detoxification effects, and reach sites thatconventional mechanical instrumentation cannot, they areone of the most promising new technical modalities fornon-surgical periodontal treatment [8–10]. The laser wave-lengths most commonly used in periodontics include thoseof diode, neodymium:yttrium–aluminium–garnet (Nd:YAG), erbium:yttrium–aluminium–garnet (Er:YAG) lasersand the carbon dioxide (CO2) laser.

The CO2 laser (wavelength 10,600 nm) is used as apulsed or continuous wave. Because of excellent soft tissueablation and adequate haemostatic and bactericidal effects[11, 12], the CO2 laser was approved in 1976 by the USFood and Drug Administration (FDA) for soft tissuesurgery, including surgery of the oral tissues. The use ofCO2 laser has been limited to soft tissue, because it isreadily absorbed by water and the hydroxyapatite mineralsthat are components of calculus, enamel, dentin andcementum, and, moreover, because it produces severethermal damage, such as melting, and cracking of rootcementum and dentin [8, 13, 14].

Er:YAG laser (wavelength 2,940 nm) is well absorbedby all biological tissues that contain water molecules.The absorption of Er:YAG laser by inorganic compo-nents is much lower than that of the CO2 laser, and,when laser is used on hard tissue, the absorption by waterand hydrous organic components occurs before the heataccumulation caused by absorption into inorganic compo-nents takes place, resulting in thermo-mechanical explo-sive ablation [8]. For this reason, Er:YAG laser isindicated not only for the treatment of soft tissues butalso for ablation of hard tissues. Aoki et al. showed theefficiency of Er:YAG to remove subgingival calculuswithout producing cracks or thermal side effects such asmelting and micro-fractures, but they also observed thatthe laser could not differentiate between calculus andhealthy tooth structures, causing a residual rough surface[15].

The Nd:YAG (wavelength of 1,064 nm), cleared by theFDA in 1990 for soft tissue removal and in 1997 forsulcular debridement, has a low absorption in water, and theenergy scatters or penetrates into the biological tissues.Several authors have reported a good bactericidal anddetoxification effect, but also adverse side effects when thiswavelength hits the cementum surface, even when lowenergies are applied, and they have concluded that the useof the Nd:YAG laser in periodontal treatment should berestricted to the area of the soft tissue treatment. Morlock etal. demonstrated that Nd:YAG laser produced externaldamage, even when irradiation was performed parallel tothe surface [16]. Ben Hatit et al. showed in 1996 that Nd:YAG associated with SRP gave a greater reduction inperiodontopathic bacterial levels than did SRP alone, butchanges in root surface were observed after the lasertreatment [17, 18].

Diode lasers are solid-state semiconductor lasers (800–980 nm) poorly absorbed in water, but highly absorbedin haemoglobin. Since diodes basically do not interactwith dental hard tissues, the FDA approved the use of adiode laser [gallium–aluminium–arsenide (Ga–Al–As;810 nm)] for oral soft tissue surgery in 1995 and forsulcular debridement in 1998 [8]. Roncati et al. observed

892 Lasers Med Sci (2010) 25:891–899

Table 1 Numbers of patients enrolled, teeth treated, and periodontal sites. Differences in clinical periodontal parameters per quadrant (ΔBOP,ΔPPD, ΔCAL), from baseline to 6 weeks after the treatment, are shown. F female, M male, Q quadrant

Patient Age (years) Gender Number of teeth Number of sites ΔBOP per quadrant ΔPPD per quadrant ΔCAL per quadrant

1 55 F 16 25 10 (Q1) 0.90 (Q1) 0.90 (Q1)

33.3 (Q2) 1 (Q2) 1 (Q2)

10 (Q3) 0.66 (Q3) 1 (Q3)

15 (Q4) 1 (Q4) 1 (Q4)

2 46 M 22 49 0 (Q1) 0.33 (Q1) 0.33 (Q1)

10 (Q2) 0.35 (Q2) 0.35 (Q2)

10 (Q3) 1 (Q3) 1 (Q3)

19 (Q4) 1 (Q4) 1 (Q4)

3 43 M 21 76 5 (Q1) 0.78 (Q1) 0.50 (Q1)

66.6 (Q2) 1 (Q2) 1 (Q2)

10 (Q3) 0.89 (Q3) 0.89 (Q3)

10 (Q4) 0.92 (Q4) 1.50 (Q4)

4 46 M 23 83 20 (Q1) 1.32 (Q1) 1.02 (Q1)

75 (Q2) 1.50 (Q2) 1.50 (Q2)

20 (Q3) 1 (Q3) 1 (Q3)

16 (Q4) 1.14 (Q4) 1.14 (Q4)

5 51 F 20 65 0 (Q1) 0.12 (Q1) 0.12 (Q1)

10 (Q2) 0.23 (Q2) 0.38 (Q2)

10 (Q3) 0.54 (Q3) 0.66 (Q3)

10 (Q4) 0.87 (Q4) 0.87 (Q4)

6 48 M 27 70 10.5 (Q1) 0.54 (Q1) 0.54 (Q1)

25 (Q2) 1 (Q2) 1 (Q2)

10 (Q3) 0.86 (Q3) 1.50 (Q3)

12 (Q4) 1 (Q4) 1 (Q4)

7 43 M 18 31 5.5 (Q1) 0.79 (Q1) 0.67 (Q1)

21.5 (Q2) 0.72 (Q2) 0.72 (Q2)

10 (Q3) 0.98 (Q3) 0.98 (Q3)

5 (Q4) 0.97 (Q4) 0.97 (Q4)

8 65 M 19 38 0 (Q1) 0.11 (Q1) 0.11 (Q1)

15 (Q2) 0.71 (Q2) 0.86 (Q2)

25 (Q3) 1 (Q3) 1 (Q3)

10 (Q4) 0.66 (Q4) 0.98 (Q4)

9 40 M 21 28 0 (Q1) 0.23 (Q1) 0.23 (Q1)

5 (Q2) 0.50 (Q2) 0.50 (Q2)

33.3 (Q3) 1.10 (Q3) 1.10 (Q3)

20 (Q4) 1 (Q4) 1 (Q4)

10 42 F 17 51 0 (Q1) 0.40 (Q1) 0.20 (Q1)

10 (Q2) 0.84 (Q2) 0.84 (Q2)

15 (Q3) 0.75 (Q3) 1 (Q3)

10 (Q4) 0.75 (Q4) 0.75 (Q4)

11 57 F 17 43 5 (Q1) 0.55 (Q1) 0.55 (Q1)

25 (Q2) 1 (Q2) 1 (Q2)

15 (Q3) 0.97 (Q3) 0.97 (Q3)

15 (Q4) 1 (Q4) 1 (Q4)

12 61 M 19 56 5 (Q1) 0.54 (Q1) 0.54 (Q1)

20 (Q2) 0.97 (Q2) 0.97 (Q2)

10 (Q3) 0.83 (Q3) 1.50 (Q3)

15 (Q4) 1.45 (Q4) 1.45 (Q4)

Lasers Med Sci (2010) 25:891–899 893

that the use of a diode laser, in association withconventional non-surgical therapy, gave greater meanvalues for clinical attachment loss (CAL), pocket probingdepths (PPD) and bleeding on probing (BOP) [19]. Intheir clinical studies Moritz and colleagues observed thatlaser therapy in combination with SRP supported thehealing of periodontal pockets by eliminating bacteria,while Kreisler et al. observed the risk of temperatureelevation of the pulp during diode laser irradiation of theroot surface [20, 21].

Added to the wavelengths currently used is that of thefrequency-doubled Nd:YAG laser, termed the potassium–titanyl–phosphate (KTP) laser, which has a range of actionsimilar to that of the 810 nm diode laser. KTP laser is asolid state laser, in which the beam, generated by a Nd:YAG laser, is directed through a potassium titanyl phos-phate crystal to produce a beam in the green visiblespectrum. It has a wavelength of 532 nm and is used asboth pulsed and continuous waves.

This laser was first introduced in medicine for severalapplications: in neurosurgery [22], in laser therapy againstbleeding [23], in aesthetic facial surgery [24] and manyothers. Since then, more than 200 scientific reports havebeen published, but very few can be found in the field ofdentistry. Zhang et al. investigated the effects of KTP laserirradiation on tooth bleaching, proving that the KTP laserwas capable of producing significantly more whiteningthan light emitting diode (LED) or diode laser andaffirming that the KTP laser was potentially a valid andsafe tool for laser-assisted tooth bleaching [25]. The studyby Kuzekanani and Walsh examined the outcomes ofphotodynamic bleaching for treatment of confirmed casesof tetracycline discoloration, concluding that in-officephotodynamic bleaching with KTP laser provided aclinically useful improvement in tooth shade in teeth with

tetracycline discoloration [26]. Nammour et al. evaluatedthe safety parameters of the irradiation conditions duringthe use of a KTP–Nd:YAG laser in root canals in order toavoid the damage to periodontal tissues, pointing out thatthe use of the KTP–Nd:YAG laser in endodontics may beconsidered to be harmless in periodontal tissues [27].Nammour and colleagues affirmed that, at certainparameters, the KTP laser can be used safely on theroot surface without having harmful temperature effectson pulp vitality and the periodontal ligament [28].

Despite so many studies, and all the lasers involved, atthe moment it is not possible for a meaningful comparisonto be achieved between various clinical studies or betweenlaser and conventional therapy, because of the differentlaser wavelengths used, the wide variations in laserparameters, the insufficient reporting of parameters that, inturn, do not allow calculation of energy density, thedifferences in experimental design, the lack of propercontrols, and the differences in severity of disease and intreatment protocols [2, 29].

It appears that there is insufficient evidence to suggestthat any specific wavelength of laser is superior to thetraditional modalities of therapy, and that there is limitedinformation available on the safety of different lasertherapies, even if no major adverse effects were reported[30]. Although there is a great need to develop anevidence–based approach to the use of lasers for thetreatment of chronic periodontitis, one may still extractsufficient numbers of data to recognize promising resultsof laser-mediated treatment of chronic periodontitis.

Since only few studies have ever taken into considerationthe use of KTP laser for the treatment of periodontal pockets[29], the aim of this study was to examine the clinicalefficacy of the KTP laser, as an adjunct to conventionalscaling and root planing.

Table 1 (continued)

Patient Age (years) Gender Number of teeth Number of sites ΔBOP per quadrant ΔPPD per quadrant ΔCAL per quadrant

13 63 M 21 54 0 (Q1) 0.20 (Q1) 0.20 (Q1)

5 (Q2) 0.42 (Q2) 0.42 (Q2)

15 (Q3) 1 (Q3) 1 (Q3)

20 (Q4) 1.20 (Q4) 1.20 (Q4)

14 50 F 18 31 5 (Q1) 0.73 (Q1) 0.73 (Q1)

0 (Q2) 0.20 (Q2) 0.20 (Q2)

15 (Q3) 0.92 (Q3) 0.92 (Q3)

20 (Q4) 1.39 (Q4) 1.39 (Q4)

15 55 F 16 30 0 (Q1) 0.11 (Q1) 0.11 (Q1)

10 (Q2) 0.66 (Q2) 0.66 (Q2)

30 (Q3) 1.30 (Q3) 1.98 (Q3)

20 (Q4) 1.10 (Q4) 1.10 (Q4)

894 Lasers Med Sci (2010) 25:891–899

Materials and methods

For this study patients were recruited from the patient poolin the Department of Clinical Odontostomatology of theSapienza University of Rome. The study was conduced inaccordance with the declaration of Helsinki and wasapproved by a Research Ethics Committee. Signed andinformed consent was obtained from all patients before thestart of examinations.

Inclusion criterion were: a minimum of four teeth in eachquadrant with the following periodontal symptoms: pocketdepth between 4 mm and 6 mm; bleeding on probing;radiographic signs of bone loss; plaque index equal to orlower than 35%.

Criteria for exclusion from the study were: periodontaltreatment within the past 24 months; systemic diseases (e.g.diabetes, cardiovascular disease) that could influence theoutcome of the therapy; history of systemic antibiotictherapy within the past 6 months or during the course ofthe study; pregnant or breastfeeding women; unwillingnessto return for follow-up examinations.

We enrolled 15 patients and treated a total of 730 sites(Table 1). If sites with a PPD greater than 6 mm werefound, we treated them, following the protocol, but did notinclude the data in the study.

A pre-trial oral hygiene phase (including toothbrushing instructions, together with teaching the useof interproximal cleaning aids such as floss and inter-dental brushes, depending on the patients’ needs) wascompleted.

Study design

For our study, we modified the design used by Kreisleret al. in their study published in 2005 [31]. The studywas performed by two clinicians. Each patient made fivevisits (Table 2), with a minimum period of 2 weeksbetween visits 1 and 2 and 6 weeks between visits 4 and 5.Visits 2, 3, and 4 took place within 1 week of each other.The clinical parameters recorded at visit 2 (baseline) andvisit 5 (6 weeks after treatment) were plaque index (PI),BOP, PPD, and CAL.

All data were collected by clinician 1 (Cl1). Scaling, rootplaning and laser treatment were performed in all patientsby clinician 2 (Cl2).

To ensure the blind character of the study, one examiner(Cl1) and one operator (Cl2) supervised the patients. Eachpatient had an examination file as well as a treatment file.The examination file provided information about theclinical measurements at each examination period. Thetreatment file included data about the treatment modalitiesand documented the processor’s completion of the therapy.Only the operator had access to that file. The patients werenot told which method of subgingival debridement hadbeen used in the respective quadrants.

We decided to treat each quadrant (Q) as follows: controlgroup, Q1,conventional instrumentation, which includedultrasonic and manual devices, and chlorhexidine (CHX)gel 0.5% (Dentosan®, Johnson & Johnson ConsumerHealthcare, USA); group A, Q2, conventional therapy,laser irradiation and CHX gel 0.5% (Dentosan®, Johnson &Johnson Consumer Healthcare); group B, Q3, conventionaltherapy and laser irradiation; group C, Q4, conventionaltherapy, beta-iodine (Betadine®, Viatris S.p.A., Milan,Italy) and laser irradiation (Table 3).

For the clinical mesurements and the mechanical therapywe used a ×3 magnification instrument (SheerVision®Incorporated, CA, USA). Our team developed a chart(Fig. 1), for which pocket probing depths were measuredat six different locations for each tooth (mesio-buccal,mid-buccal, disto-buccal, disto-lingual, mid-lingual, andmesio-lingual) with a manual periodontal probe (CP 15

Table 3 Different types of treatment for each quadrant

Groups and respective treatment

Control group (Q1) Group A (Q2)

Mechanical instrumentation Mechanical instrumentation

CHX 0.5% gel Laser irradiation

CHX 0.5% gel

Group C (Q4) Group B (Q3)

Mechanical instrumentation Mechanical instrumentation

Iodopovidone solution Laser irradiation

Laser irradiation

Table 2 Actions taken at the five different visits (Cl1 clinician 1, Cl2 clinician 2)

Session Action taken

Visit 1 (both clinicians) Patient’s recruitment, oral hygiene instructions, removal of supra/subgingival calculus, and plaque

Visit 2 (Cl1) Clinical measurements (baseline values)

Visit 3 (Cl2) Treatment of quadrants 1 and 2, according to the protocol

Visit 4 (Cl2) Treatment of quadrants 3 and 4, according to the protocol

Visit 5 (Cl1) Clinical measurements

Lasers Med Sci (2010) 25:891–899 895

UNC, Periodent, USA). Recessions, CAL, mobility, PIand BOP were also evaluated at all aspects.

Pockets depths that were equal to or ranked above 4 mmwere coloured red, healthy gingival sulci were colouredgreen. We decided to develop this chart in order to facilitatecommunications with the patients when teaching them theirhome oral hygiene care.

For the subgingival mechanical instrumentation we firstinvestigated the presence of subgingival calculus with aperiodontal explorer 11–12 (Periodent, USA).

The treatment followed with the use of Ultra Sound(P1 periodontal point. EMS, Switzerland), an H5/33scaler (Hu-Friedy Co., Chicago, IL, USA) for all teeth,a universal 1–2 mini-curette (LM-Planmeca, Helsinki,Finland), to treat the latero-posterior teeth, and a Gracey1–2 mini-microcurette (Hu Friedy) for the anterior teeth.The treatment was continued until complete debridementof the tooth surfaces had been accomplished. Followingmechanical instrumentation, the sites were rinsed with asodium chloride (NaCl 9%) solution.

After scaling and root planing, each quadrant wastreated according to the protocol, and, when the KTPlaser was operated (λ 532 nm, SmartLite, DEKA, Italy),

the following parameters were utilized: output power0.6 W in pulsed mode [time on (Ton) 10 ms, time off(Toff) 50 ms], fluence 19 J/cm2, laser light delivered via a200 μm optical fibre. The fibre was inserted into theperiodontal pocket, the laser was activated, and the fibrewas slowly moved from apical to coronal direction in a

Fig. 2 The 200 μm fibre, inserted into the periodontal pocket, duringlaser irradiation

Fig. 1 Example of periodontal chart used to record PPD, CAL and BOP

896 Lasers Med Sci (2010) 25:891–899

sweeping motion during laser irradiation (Fig. 2). Thiswas done mesially, distally, buccally, and lingually. Eachlaser-treated pocket was irradiated for 30 s, and thetreatment was repeated three times with a resting time ofat least 30 s for each tooth. All treatments from thebeginning were performed under local anaesthesia.When the laser was used, both patients and the operatorwore protective glasses. At the end of the first period oftreatment, each patient received instructions for homecare. To compensate for potential individual variationsin plaque control among the subjects, and to reducepathogens present on other oral surfaces, we instructedall the patients to rinse twice a day with a mouthwash(Listerine®, Johnson & Johnson Consumer Healthcare).

After 6 weeks, patients attended a control visit, with thecompletion of a new periodontal chart for evaluation ofPPD, CAL and BOP. All data collected were entered into anExcel database and were proofed for entry errors. A non-parametric statistical evaluation was conducted usingsoftware (GraphPad Prism 5.0) to assess the effectivenessof the study.

We first proceeded with an analysis of variance(ANOVA) with a Kruskal-Wallis test, to evaluate thestatistical significance of the total results. Moreover, allgroups were compared with each other with the Dunn’stest, to assess whether there were statistically significantdifferences between them.

Results

All the groups showed an improvement in the clinicalparameters (BOP, PPD, CAL) (Table 4). Results of thestatistical analysis showed that, for the BOP, there weresignificant differences between all groups, while, for CALand PPD, groups B and C showed statistical differences whencompared with the other groups, but not between them(Table 5).

PPD decreased in all groups, especially in the lased ones. Inparticular, groups B and C showed statistically significantdifferences when compared with the other groups (P<0.001),but not between them. Group C was the most positivelyinvolved by laser irradiation, with an improvement of1.03 mm in PPD. All the groups showed an improvement

Fig. 3 Mean differences in PPD and CAL in the four groups frombaseline to 6 weeks after treatment (CTR control)

Fig. 4 Mean differences in CAL from baseline to 6 weeks aftertreatment in all first molars (CTR control)

Table 5 Significant differences between all groups were obtained forBOP. For CAL and PPD, groups B and C showed statisticaldifferences when compared with the other groups, but not betweenthem. Ctr control group, NS not significant

Test BOP PPD CAL

Kruskal–Wallis P<0.0001 P<0.0001 P<0.0001

Dunn, Ctr vs A P<0.001 NS P<0.001

Dunn, Ctr vs B P<0.001 P<0.001 P<0.001

Dunn, Ctr vs C P<0.001 P<0.001 P<0.001

Dunn, A vs B P<0.001 P<0.001 P<0.001

Dunn, A vs C P<0.001 P<0.001 P<0.001

Dunn, B vs C P<0.001 NS NS

Table 4 Improvements in the clinical periodontal parameters (PPD,BOP and CAL) in all treated groups

Group PPD BOP CAL

Control 0.51 mm −4.4% 0.45 mm

A 0.74 mm −21.9% 0.76 mm

B 0.92 mm −15.9% 1.10 mm

C 1.03 mm −14.5% 1.09 mm

Lasers Med Sci (2010) 25:891–899 897

in CAL too. In particular, the best results were obtained ingroups B and C (P<0.001) (Fig. 3).

In the evaluation of the treatment of 6 mm, 5 mm or4 mm pockets, no statistically significant differences wereobserved (P>0.05). Moreover, when we analysed firstmolars, often involved in periodontal disease but difficultto treat because of their anatomy (root concavities,furcation, developmental grooves, etc.), a significant reduc-tion in CAL was observed (P<0.001). Finally, when weevaluated BOP, the irradiated groups (A, B, and C) showedstatistically significant differences, both between the controland between themselves (P<0.001). In particular, group Awas the most positively affected by laser irradiation, withan improvement of 21.9%. (Fig. 4).

Discussion

At present, scaling and root planing remain an essential partof successful periodontal therapy, but when pocket depthincreases, especially when probing depth exceeds 5 mm,bacterial plaque and calculus can only be removed to acertain extent [32]. The persistence of bacteria and calculuson the surface of the pockets can be considered as the maincause for the failure of non-surgical periodontal treatment[33]. For this reason, in the past decades, several treatmentalternatives have been presented. Application of antibioticsor full-mouth treatment was found to provide someadditional benefit in the treatment of chronic periodontitis[34], but many controversial results have been reported thatdemonstrated no significant effect on the healing process ofperiodontal tissue [7]. Lasers were shown to be feasible andeffective tools for the disinfection of root surfaces. Thisholds true for the Er:YAG laser as well as for the diode andNd:YAG lasers [18, 35, 36] . Schwarz et al. suggested thatfrom a clinical point of view, the Er:YAG may serve as analternative treatment modality to conventional periodontaltherapy [37].

The results of our study demonstrated that periodontalpockets treated with KTP laser showed an improvementin all BOP, PPD and CAL measurements when they werecompared with those from conventional therapy only.Initial mean PPD for all groups was 5.17 mm andchanged to 4.79 mm with conventional therapy and4.24 mm for the lased groups. Clinical attachment lossdecreased in all groups, but the most significant resultswere found in the lased groups. In particular, the bestresults occurred in groups B and C, which showedstatistically significant differences when compared withother groups (P<0.001). In group C the results find theirreasons in the optical properties of the 532 nm wave-length, where a brown colour can enhance the laserirradiation.

Our findings show that the KTP laser was effective as anadjunct to mechanical and chemical treatment. This wasprobably due to the thermal effect, which creates antimi-crobial activity without damaging the dental tissues [9–11].By contrast, and similarly to lasers of other wavelengths(e.g. Nd:YAG, diode, etc.) [17, 20] the KTP laser alone,due to its physical properties, is not able to remove calculuson root surfaces. In our study conventional therapy alonegave good results, but they were lower than those oftherapy combined with laser irradiation. The improvementsin all the clinical parameters showed a significance in theprognosis of the periodontal status of the patient, inaccordance with the systematic review of Van der Weijdenand Timmerman [38].

Our results were consistent with those described forthe diode laser [20, 37]. A study by Nammour et al. andone by Machida and colleagues drew the conclusion thatthe KTP laser could be safely used on the root surfacewithout having harmful temperature effects on pulpvitality and the periodontal ligament if applied at reason-able settings [28, 39]. If one considers all the factsdescribed, it can be concluded that the KTP laser may bea suitable tool for non-surgical periodontal treatment andcan be safely used if the common precautions are observedand the applied energy stays within the proposed range. Tofurther confirm the results, more clinical studies arenecessary.

References

1. Kinane DF, Attstrom R, European Workshop in Periodontologygroup B (2005) Advances in pathogenesis of periodontitis.Group B consensus report of the fifth European Workshop inPeriodontology. J Clin Periodontol 32:130–131

2. Karlsson MR, Diogo Löfgren C, Jansson HM (2008) The effect oflaser therapy as an adjunct to non-surgical periodontal treatment insubjects with chronic periodontitis: a systematic review. JPeriodontol 79:2021–2028

3. American Academy of Periodontology. Periodontal procedures.Available at http://www.perio.org/consumer/procedures.htm.Accessed 16 January 2009

4. Arabaci T, Çiçek Y, Çanakçi CF (2007) Sonic and ultrasonicscalers in periodontal treatment: a review. Int J Hyg 5:2–12

5. Hunter RK, O’Leary TJ, Kafrawy AH (1984) The effectiveness ofhand versus ultrasonic instrumentation in open flap root planing. JPeriodontol 55:697–703

6. Bonito AJ, Lux L, Lohr KN (2005) Impact of local adjuncts toscaling and root planing in periodontal disease therapy: asystematic review. J Periodontol 76:1227–1236

7. Braun A, Dehn C, Krause F, Jepsen S (2008) Short clinical effects ofadjunctive antimicrobial photodynamic therapy in periodontaltreatment a randomized clinical trial. J Clin Periodontol 35:877–884

8. Aoki A, Saski KM, Watanabe H, Ishikawa I (2004) Lasers innonsurgical periodontal therapy. Periodontol 36:59–97.

9. Todea Colojoara C, Miron M (2003) Comparative study of twotreatment procedures in periodontitis: Nd:YAG laser with

898 Lasers Med Sci (2010) 25:891–899

biodegradable chlorhexidine chip (CHX) and manual curettagewith CHX. Int Congr Ser 1248:347–351

10. Sennhenn-Kirchner S, Klaue S, Wolff N, Mergeryan H, Borg vonZepelin M, Jacobs HG (2007) Decontamination of rough titaniumsurfaces with diode lasers: microbiological findings on in vivogrown biofilms. Clin Oral Implants Res 18:126–132

11. Sasaki KM, Aoki A, Ichinose S, Ishikawa I (2002) Morphologicalanalysis of cementum and root dentin after Er:YAG laserirradiation. Lasers Surg Med 31:79–85

12. Kojima T, Shimada K, Iwasaki H, Ito K (2005) Inhibitory effectsof a super pulsed carbon dioxide laser at low energy density onperiodontopathic bacteria and lipopolysaccharide in vitro. JPeriodontal Res 40:469–473

13. Lobene RR, Bhussry BR, Fine S (1968) Interaction of carbondioxide laser radiation with enamel and dentin. J Dent Res47:311–317

14. Tucker D, Cobb CM, Rapley JW, Killoy WJ (1996) Morphologicchanges following in vitro CO2 laser treatment of calculus-ladened root surfaces. Lasers Surg Med 18:150–156

15. Aoki A, Miura M, Akiyama F, Nakagawa N, Tanaka J, Oda S,Watanabe H, Ishikawa I (2000) In vitro evaluation of Er:YAGlaser scaling of subgingival calculus in comparison with ultrasonicscaling. J Periodontal Res 35:266–277

16. Morlock BJ, Pippin DJ, Cobb CM, Killoy WJ, Rapley JW (1992)The effect of Nd:YAG laser exposure on root surface when usedas an adjunct to root planing: an in vitro study. J Periodontol63:637–641

17. Ben Hatit Y, Blum R, Severin C, Maquin M, Jabro MH (1996) Theeffect of a pulsed Nd:YAG laser on subgingival bacterial flora and oncementum: an in vivo study. J Clin Laser Med Surg 14:137–143

18. Chilà A, Possenti A, Palaia G, Ripari A, Romeo U, Gambarini G,Moroni C, Tarsitani G, Petti S (2003) Antimicrobial activity ofNd:YAG laser in endodontics. J Dent Res 82:184 no. 1378

19. Roncati M, Concon E, Botti RH, Romeo U, Calura G (2007) Nonsurgical diode laser-assisted periodontal instrumentation: a clinicalstudy. Doctor Laser 3:53–61

20. Moritz A, Schoop U, Goharkhay K, Schauer P, Doertbudak O,Wernisch J, Sperr W (1998) Treatment of periodontal pockets witha diode laser. Lasers Surg Med 22:302–311

21. Kreisler M, Al-Haj H, D’Hoedt B (2002) Intrapulpal temperaturechanges during root surface irradiation with an 809-nm GaAIAs laser.Oral Surg Oral Med Oral Pathol Oral Radiol Endod 93:730–773

22. Gamache FW, Patterson RH (1990) The use of the potassiumtitanyl phosphate (KTP) laser in neurosurgery. Neurosurgery26:1010–1014

23. Taylor JG, Disario JA, Bjorkman DJ (2000) KTP laser therapy forbleeding from chronic radiation proctopathy. Gastrointest Endosc52:353–357

24. Kulick MI (1996) Evaluation of KTP 532 laser in aesthetic facialsurgery. Aesthet Plast Surg 20:53–57

25. Zhang C, Wang X, Kinoshita JI, Zhao B, Toko T, Kimura Y,Matsumoto K (2007) Effects of KTP laser irradiation, diode laser,and LED on tooth bleaching: a comparative study. PhotomedLaser Surg 25:91–95

26. Kuzekanani M, Walsh LJ (2009) Quantitative analysis of KTPlaser photodynamic bleaching of tetracycline-discolored teeth.Photomed Laser Surg 27:521–525

27. Nammour S, Kowaly K, Powell L, Van Reck J, Rocca JP (2004)External temperature during KTP-Nd:YAG laser irradiation in rootcanals: an in vitro study. Lasers Med Sci 19:27–32

28. Nammour S, Rocca JP, Keiani K, Balestra C, Snoeck T, Powell L,Van Reck J (2005) Pulpal and periodontal temperature rise duringKTP laser use as a root planing complement in vitro. PhotomedLaser Surg 23:10–14

29. Cobb CM (2006) Lasers in periodontics: a review of the literature.J Periodontol 77:545–564

30. Schwarz F, Aoki A, Becker J, Sculean A (2008) Laser applicationin non surgical periodontal therapy: a systematic review. J ClinPeriodontol 35:29–44

31. Kreisler M, Al Haj H, D’Hoedt B (2005) Clinical efficacy ofsemiconductor laser application as an adjunct to conventionalscaling and root planing. Lasers Surg Med 37:350–355

32. Cobb CM (1996) Non-surgical pocket therapy: mechanical. AnnPeriodontol 1:443–490

33. Cobb CM (2002) Clinical significance of non-surgical periodontaltherapy: an evidence-based perspective of scaling and rootplaning. J Clin Periodontol 29:6–16

34. Schwarz F, Becker J (2005) Treatment of periodontitis and peri-implantitis with an Er:YAG laser: experimental and clinicalstudies. Med Laser Appl 20:47–59

35. Schoop U, Kluger W, Dervisbegovic S, Goharkhay K,Wernisch J, Georgopoluos A, Sperr W, Moritz A (2006)Innovative wavelengths in endodontic treatment. Lasers SurgMed 38:624–630

36. Castro GL, Gallas M, Nunez IR, Borrajo JLL, Garciavarela L(2006) Histological evaluation of the use of diode laser as anadjunct to traditional periodontal treatment. Photomed Laser Surg24:64–68

37. Schwarz F, Sculean A, Berakdar M, Szathmari L, Georg T, BeckerJ (2003) In vivo and in vitro effects of an Er:YAG laser a GaAIAsdiode laser, and scaling and root planing on periodontally diseasedroot surfaces: a comparative histologic study. Lasers Surg Med32:359–366

38. Van der Weijden GA, Timmerman MF (2002) A systematicreview on the clinical efficacy of subgingival debridement in thetreatment of chronic periodontitis. J Clin Periodontol 29:55–71

39. Machida T, Wilder-Smith P, Arrastia AM, Liaw LH, Berns MW(1995) Root canal preparation using the second harmonic KTP:YAG laser: a thermographic and scanning electron microscopicstudy. J Endod 21:88–89

Lasers Med Sci (2010) 25:891–899 899