Periodontics

Comparison of the clinical effects of snbgingival applicationof metronidazole 25% gel and scaling in the treatment of adultperiodontitis

Fatin Arab Awartani. BDS, MSVBashir Jalaldiii Zulqartiain, DDS, MS«*

Objective; Contml of suiygmgivat plaque is of paramount importance in the treatment of periodontal diseases.Tiie role of subgingivai sustained-relea.se antibiotic therapy needs elucidation. A .^ingle-blind clinicai trial wascarried out in ¡3 patients with aduh periodontitis to compare the effects of subgingival application ofmetm-nidazolc dentai gel with those of subgingival scaiing.Method and materials: A split-mouth design was used so that each patient received all treatments simultane-ously. Randomly selected quadrants were treated with application of 25% metronidazole get. subgingival scal-ing, or a combination of scaling and gel application. Tiie remaining quadrant in each patient was iefl untreatedas a control.Results: Ail tiiree treatments were effective in significanlly reducing Plaque Index. Gingival Index, and bleed-ing on probing over the 14-week ob.ser\'ation period. No stati.sticaiiy significant diffeivnces were found ijetweenscaling alone and conMned treatment. Scaling and combined treatment were better than metronidazole. Metro-nidazole produced transient effects, best noted during the first 4 weeks afler treatment. No additive effect ofmetmnidazole was noted in the combined treatment. At week 14, oniy combined treatment sites and scaied .sitesshowed statistically greater probing depth reduction than control sites.Conclusion: For the treatment of inild-to-moderate adult periodontitis, subgingivat .scaling alone is as effectiveas the combination of scaling and antibiotic therapy. (Quintessence Int 1998.27.41-481

Key words: adult pertodontitis. bleeding on probing. Gingival Index, metronidazole gel. Plaque Index, probingdepth, subgingival antibiotic therapy, subgirtgival sealirtg

Clinical relevance

The computer image analysis technique is a poten-tially powerful evaluating tool for botb laboratoryand elinical investigations on the stain removal efft-cacy of dentifrices. All dentifrices tested couldremove some mature stains, and one dentifrice tar-geted toward stain removal was more effective thanthe other.

"LetLurer, Division of Penodontics. Department of Preventive DentülSciences. College of Dentistry, King Saud University. Riyadh, SaudiArabia.

-*A.ssüciale Professor and Head, Division of Periodontics. Department ofPrevenLive Dental Stienee.i, College of Dentistry, King SaudUniversity. Riyadh. Saudi Arabia.

Reprint requests: Dr Patin Awarlani, College of Denli.'itrj. King SaudUniversily, PO Box fil)169. Riyadh 11545. Süudi Arühia. E-mailF5OE0n@ksu.edu.sa

Tbe cause-and-effect relationship between plaquemicroorganisms and periodontal disease is well

documented.'- Plaque begins to re-form almost imme-diately after its removal: it must tberefore be removedregularly to prevent and/or treat periodorttal disease.'-'Thus, periodontal therapy has ineluded mechanicalremoval of supra- and subgingival plaque and calculus.Complete removal of imtants by mechanical means isdifficult to obtain because of inaccessibility to peri-odontal instrumentation.•*•'' Therefore, tbe search forsupplementary antimicrobial substances to control themicroflora has been extensive. Botb systemic and topi-cal administration of antibiotics have been clinicallytested for tbe treatment of penodontitis."

Topical application of metronidazole into gingivalpockets bas been found to be an effective adjunct toconventional treatment, with beneficial effects on clini-cal and microbiologie parameters.^'" Baker et al" baveshown that the lowest concentration of metronidazolerequired to inhibit 50% of the strains (MICsiO is lessthan I (ig/mL for relevant anaerobes such as Porphy-romonas ^ingivalis, Prevoletia intermedia. Fuso-

41

Awartan i/Zu Iqa main

bacterium iiiicleaUiiii. ;ind Wolineltu recta. Stoltze'- de-icrmitied that after a single subgingival application of25% mctronidazolc gel (mean dose 2 to 5 mg pertooth), a coticentratioii higher than I \.\JmL was obtainedin all samples at 4 and 8 hours, in 92% after 12 lioiirs.in 50% after 24 hours, and in 8% after 36 hours.

Six-month efficacy studie.s have shown thai twu appli-cations of 25% metronida2ole dental gel (applied once aweek for 2 weeks) is et|iiivalent to subgingival scaling inits effect on probing depths and bleeding on probing inpatients with adult periodontitis.'-'•'•' The microbiologieparameters confirmed the change toward a plaque com-position compatible with a healthy state. Subgingivalscaling combined with the local application of an antimi-crobial agent may be the treatment of choice,'-'

Review of the literature

Systemically administered nietronidazole is able toinhibit the development of plaque and gingivitis in ani-mals'^ or alter the composition of plaque and reduceinfiltrated connective tissue'" and to stabilize the bacte-rial counts.'' In humans, it was found that in theabsence of scaling and root planing, systemic metron-idazole reduced the mean probing depths by 0.4 to 2,4mm.' --" Systemic metronidazole resulted in improve-ments that were sustained for 28 weeks; however, rootplaning resulted in greater clinical improvement thandid metronidazole,-'

The effects of subgingival 40% metronidazole ap-plied once weekly for 4 weeks and 0.2% chlorhexidinesolution self-administered subgingivally once daily for4 weeks after initial scaling and root planing were com-pared by Yeung et al.-- Highly significant improvementin periodontal health was noted over a 3-month period,and this result was maintained to the end of the study.There were no significant differences between the twotreatment groups at any time except for sulcular hieed-ing index, whieh at week 7 and week 12 showed metro-nidazole to be more effective.

Klinge et al'' determined that probing depth iPD).bleeding on probing (BOP), and Gingival Index (Gl)improved significantly in six beagle dogs with experi-mental periodontitis on the 25% metronidazole gel-treated side compared to the placebo-treated side.Klinge et al" also studied the effects uf 25'^' metron-idazoie gel in (il patients in a multicenter study com-paring four treatments: subgingival scaling, 25%'nietronida7olc dental gel applied twice a week for 2weeks, 15% dental gel applied once a week for 2weeks, and 15% dental gel applied twice a week for 2weeks. All four treatment methods were effective inreducing probing depths and bleeding on probing, and

all three antibiotic regimens yielded results comparableto the results after subgingival scaling."

Ainamo ct al'-' compared 25% metronidazole dentalgel with suhgingival scaling for the treatment of adultperiodontitis in 206 patients, of whom 199 completedihe nine-center study. The gel was applied at 0 and 7days in two randomly selected quadrants. Subgingivalscaling wa,s done on two sessions. The average PD andfrequency of BOP were calculated over all sites, wilh aninitial PD of > 5 mm. Both treatments were effective insignificatitly reducing probing depth and bleeding onprobing over a 6-month period. The mean PD was 5.9mm for gel-treated quadrants and 5,8 mm before subgin-gival scaling. Probing depth was reduced in the twogroups by 1.3 and 1,5 mm, respectively, after 24 weeks.Bleeding on prohing was reduced by 32% after gel ap-plication and 39% afler scaling. The difference betweenthe treatments was statistically significant but was con-sidered clinically unimportant, Radvar et al-''foundgreater improvement in clinical parameters in combinedtreatment groups than in groups treated with scaling androot planing alone: adjunctive treatment with tetracy-cline gave better results than combined treatment with2% minocycline gel or 25% metronidazole gel.

The effect on periodontal healing of local applicationof 25% metronidazole gei after guided tissue regenera-tion procedures using expanded polytetrafluoroethylenemembranes was reported by Sander et al,--'' Six monthsafter the removal of membranes, the median gain inprohing attachment level as a percentage of the initialdefect depth was 929Í- for test defects and 50% for con-trol defects. Results indicate that local application ofmetronidazole gel has a beneficial effect on healing ofperiodontal vertical defects tteated by guided tissueregeneration. Loesche et al-" reported a reduced needfor periodontal surgery following phased application ofmetronidazole in patients with severe periodontitis.

The present study was carried out to test simultane-ous application of Elyzol gel (Dumex) with subgingivalscaling and see if differences exist in the responses ofshallow and deeper periodontal pockets.

Method and materials

The study was carried out as an open, single-blind(operator-blind), randomized, controlled clinical trialcomparing subgingival application of 25% mett-onida-zole dental gel with and without .subgingival scaling tosubgingival scaling alone. A split-mouth design wasused, whereby the patients received all treatmentssimultaneously, each treatment in one randomly selectedquadrant of the dentition. The fourth quadrant served ascontrol.

42 Volume 29. Number 1. 199g

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Pütients were included in the study if ihcy had atleast one tooth in each quadrant with a probing depth of> 5 mm but were excluded if they had u.sed antibioticsin the last 3 months, had received periodontal treatmentin the last d months, or had severe periodontal disease.All patienls included gave informed consent after hav-ing received verhal and written information about thestudy. The research protocol was approved by theResearch Center of the College of Dentistry, King SaudUniversity.

Treatment pmtocol

Each quadrant was randomh selected to receive one ofthe following treatments:

1. Appl ica t ion of 25*^ metroniduzole denial gel(Elyzo!) only. The drug was supplied in standard 1.8-mL glass cartridges containing 250 mg of metro-nidazole. The gel was applied with -A syringe with ablunt cannula and placed in the bottom of all suiciand pockets around the teeth in the quadrant on days0 and 7. Excess gel was removed gently with cottonapplicators: thus the exact amount received was notcalculated.

2. Suhgingi\al scaling. Subgingival scaling was per-formed in one session under local infiltrationanesthesia (2% lidocaine with 1:80.000 epinephrine,1.8 mL per quadrant). Moderate to heavy supiagin-gival calculus was retnoved by ultrasonic scalingwitb Cavitron 2002 (Dentsply). Subgingival scalingatid root planing was performed as needed withHu-Friedy rigid Gracey Curettes.

3. Subgingival scaling and Ely/ol gel application (com-bined treatment). When subgingival scaling wascotnpleted. Elyzol gel was applied as explained earli-er, after complete hemostasis was ohtained throughgentle pressure with cotti)n gau¿e.

4. Untreated control quitdrant. This quadrant receivedno treatment.

Probing depth was measured with the Florida Elec-tronic Probe (Florida Probe), which measures to thenearest O.I mm. with 25 Pa standardized pressure: theprobe tip diameter is 0.4 tnm. Bleeding on probing wasassessed according to a modification of the bleedingindex described by Ainamo and Bay,-' Bleeding onprobing was recorded as positive if bleeding occurredwithin 10 10 30 seconds after gentle probing with theFlorida probe. The Gingival Index was recorded asdescribed by Ainamo and Bay.-' The GI was recorded aspositive if there was inflammation at any surface. ThePlaque Index (PI) used was that of Silness and Loe.-"

Quintessence International

Clinical parameters were recorded before treatment(baseline) and at 2. 4. 6, and 14 weeks after completionol subgingival scaling. The .sequence tor obtaining mea-surement was standardized as follows: Gingival Index.Plaque Index, bleeding on probing, and probing depth.All measurements were recorded by one exatniner (FA].Oral hygiene instructions were given immediately afterthe baseline examination measurements were completedand were reinforced throughout the study. The instruc-tions were personalized according to each patient'sneeds.

Statistical tn et hods

Statistical analysis system ¡SAS] was utilized for al!statistical analysis. Analysis of variance (ANOVA] forrepeated-measures design was used with respect to fourquadrants and five visits. Tukey's and Scheffe's multiplerangi. tests were employed for determining the signifi-cance of measurements between the pairs of the differ-ent parameters.

Results

Thirteen male patients participated in the study. Twelvepatients completed the l4-weel\ observation period, onepatienl failed to show up for the last examination. Themean age of participants was 37.3 years (range 28 to 57years). Two hundred forty-seven teeth were included: ofthese. 62 teeth were treated with Elyzoi gel. 63 withsubgingival scaling. 60 received combined treatment,and 62 served as untreated controls. No untoward expe-riences were reported by the participants.

Prohing depth

A total of 1.482 sites were registered (sealing, 378:Elyzol. 372: combined treattnent. 360: and control sites.372). The mean probing depth per quadrant (n = 13) ispresented in Table 1. No statistically significant differ-ences were found between the mean probing depths ofthe quadrants allocated to the different treatments atbaseline. Other than the expected difference betweenthe Ireatment methods and the control, no significantdifferences were observed between various tteatmentsat different time intervals.

Further analysis, ba.sed on classification of the pock-ets as "shallower'" when < 4.4 mm or "deeper" when> 4.5 mm. revealed some significant findings. Alter 4weeks, shallower pockets were reduced by 19.7'?'- withcombined treatment, by 12.5'7f when scaled, and by10.7% with Elyzol treatment (Table 2). There was a sta-tistically significant difference in the reduction of the

43

Awartani/Zuiqarnain

TABLE 1 Mean baseline periodontal probing depths (mm) and meanreduction of probing deptlis (mm) at various time intervals'

TimeScaling

(n = 378)Eiyzoi

¡n = 372)Combinedin = 360)

Control(h = 372)

BaseiineReduction at week 2Reduction at week 4Reduction at week 6Reduction at week t4

4,650,110,300,320,33

1 reduction at week 14) (7,1)

4,580,140,210,250,15

(3 3)

4,610 130,320,210,21

(4,6)

4.530.010.030.010.04

(0.91

'Tiie reduclion at trie foiiow-up i/isif is based on comparisons willi Ihs baseiine vaiues,n = njmberof sites.No slatislicaiiy significant differences were tourO among the vanDJE treafment metfiods or af different(me intervais.

TABLE 2 Reduction in the mean periodontal probingdepths of shallower pockets (< 4.4 mm) followingvarious treatment regimens

Base i meprobing

Treatment depth (mm)

Reduclion in probing depttiWeek 4 Weeii 14

Scaling 3 11^'

Eiyzoi 3 18"'

Combined 3.15a

Control 3.111'

12.5 (0,39)"» 14,8 (0,46)':^

10.7 (0.34)^s 7,5 ( 0 ,24 ) ' "

19.7 (0.62)"= 12,6 (0.38)'OE

0.3 (+0.01)i-'; 3.2 (0.46)i'a

Vaiues witii the same superscripl ietter are not statistically different alP> ,05. Upper case leflers indicate no signiticanf difference wHhin col-umn: iower case ieflers indícale no signiticanf difference wifhin rovus

TABLE 3 Reduction in the mean periodontal probingdepths of deeper pockets (> 4.5 mm) followingvarious treatment regimens

Reduclion in probing depth

Treatrnent

Scaling

Etyzol

Combined

Baseiineprobing

deptti (mm)

5.06=«

5.05^«

5.049'

4.971«

Weei<4 Week 14(mm)

20.8 (1,05)''= 29.4 (1.49)°

19.6 (0,99)'Ei 21.9 (I.Oa)''

25.6 (129)i'B 29.8 (150)'

6.4 (ÜÍ2)"- 14 1

Values Wim tfie same superscript letter are not statislically Oifterent atP> ,05, Upper case letters indicate no significant difference within coi-umn, iower case letters indicate no significant difference within rows.

probing depth between Eiyzoi sites atid the control sitesLifter 4 weeks but not after J4 weeks. Scaling resulted ina significantly greater redtiction in probing depth thandid Eiyzoi treatment alone at week 14; however, no sig-tiificant difference was found between Eiyzoi and com-bined treatment after either 4 or 14 weeks.

The deeper pocket.s showed greater probing depthreductions after 4 weeks (Table 3). Combined treatmentresulted in 25,6% reduction, scaling in 20.8% reduction,and Eiyzoi treattnent in 19.6% reduction. The quadrantsdid not show any significant differences in probingdepth reduction after 4 weeks. After 14 weeks, however,scaled quadrants showed statistically significantlygreater reduction in probing depth than did Elyzol-treated one.s. Compared to the control, al! treatments ob-tained significantly greater reduction in probing depthafter 4 weeks, but after 14 weeks only combined treat-

ment sites and scaled quadrants showed a statisticallygreater reduction in probing depth. The control quad-rants also showed a mean reduction in probing depth ofI4.IÍÍ after 14 weeks, which has to be taken into con-sideration (Table 4),

Bleeding on probing

The three treatment groups showed highly stutisticaiiysignificant reduction in BOP during the Urst 2 weeks.At week 14. ail treatment sites and the control sitesshowed statistically significant reduction compared tothe baseline data (Table 5). Eiyzoi produced sig-nificantly greater reduction in BOP than did the controlup to week 14, The effect of combined treatment andscaling alone was significantly greater than that ofEiyzoi Lilone. There was no statistically significant dif-

44 Voiume 29. Number i ,

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l^^^l t Levels ol significance ol between treatment comparisons of probingdepth (> 4.5 mm)

Scaiing uscontrol

Elyzoi vscontrol

Combinedvs control

Scaling vsEiyzol

Scaling vscombinea

Elyzoi vscombined

0 0.2669 0.3138 0 50304 0.0025- 0.1010- 0.0196-14 0.1449- 0.2249 00120-

0.B5230.29980.0315'

0.B751 1 00000.5697 0.23470.8826 0.0779

-Significan (P< .05).-Highly significant {P< 01).

Treatment

ScalingElyzoiCombinedControl

aiBüBa BBleeding on prob

Baseline

Mean ::: SD

0 855 ±0.200 844 ±0.190.779 ± 0.300.789 ± 0.20

•Significanl(P<.051."Highly significant ( P î 01¡.••-Very Highly significant 1P< .0011

Week 4

Mean ± S D

0.251 s 0.230.336 ± 0.230.214 3-0.270.556 ± 0.33

ng

Week 14

Mean + SD

0 197 ±0.070 419 ±0.240 198 ±0.160 563 ± 0.30

Significance

Baselinevs week 2

.0003"-

.0001-

.0003—

.3500—

Baselinevs week 14

.0001-

.0001-,0001-,0091"

ference between the effects of combined treiitmcnl andscaling alone on bleeding on probing.

Gin a i va I Index

All three treülmenis and ihe conuol rcsuliL-d in highlystaiistically significant reductions of Gl during ihe first 2weeks posttreatment. Intereslingly. between weeks 4 and6, Elyzol-treated quadrants showed a statistically signifi-cant increase in Gl. At week 14. all sites, including thecontrols, showed highly statistically significant reduc-tions compared to the baseline data ("fable 6). Both com-bined treatment and scaling alone resulted in signifi-cantly higher reductions in Gingival Index than Elyzoitreatment or no treatment.

Plaque Index

All treatment groups e.xhibited statistically significantreductions in PI alter week 2 and up to 14 weeks post-treatmeni (Table 6). Both scaling alone and combinedtreatment resulted in significantly greater plaque reduc-tion than did Elyzoi treatment alone. There was no statis-tically significant differencii in plaque reduction betweenElvzol-treated quadrants and controls.

Discussion

The present trial was performed as a randomized in-traindividual study using the split-mouth design andwas ba.sed on 13 patients (12 at the 14-week observa-ti(m] suffering from early to moderate periodontitis.There is the risk of overlapping contamination when anantibiotic is tested in the trial. Loesche et al-" observedthat metronidazole has a specific activity against gram-negative microorganisms and has no ant iplaqueproperty. Stolze and Stellfeld'" have shown that Ihe sys-temic uptake of intraoral topical application of metro-nidazole is minimal. Both systemic and local metro-nidazole administration decrease PI and Gl scores--"-^-by changing the qualitative composition of microbiotain periodontal pockets. Such changes do not decreasethe PI but may explain the improvement in Gl.'"

The split-mouth design and randomized allocationof quadrants to the three treatments in the present trialresulted in similar baseline values with no distinct dif-ferences in any of the parameters. The use of the fourthquadrant as control within the same patient annulledthe inliuence of dependent variables. All participantsreceived professional oral hygiene instructions, begin-ning at day 0. Thus, the reduction in inflammation and

Quintessence International 45

Awarlani/Zulqarnain

TABLE 6 Gingival index (Gi) and Piaque index (PI) for various treatmentgroups

Treatment

Scaling GIScaling PIElyzol GIElyzol PICombined GICombined PIControl GIControl PI

•Significant |P e

Gingival

Baseline

Mean + SD

0.971 + 0.051.239+ 0.4t0.946 + 0.101.377+ 0.4B0.953 + 0.071.520 + 0.490.967 + 0.061.365 ± 0.43

.05)."HigWy signHicani(Pe.OI).'•"Very highly s gnilicart(Pi .Out).

ndex and Plaque Index

Week 4

Mean i- SD

0.233 + 0.320.285 + 0.250.475 ± 0 300.385 + 0 320.253 + 0 310.357 + 0 230.711 +0.240.574 + 0.27

Week 14

Mean ± SD

0.346 + 0.210.423 + 0.270.615 ±0.290 652 ± 0 290 333 + 0.180.463 ±0.230.711 ±0.240.656 + 0.20

Significance

Baselinevs week 2

.0001 -

.0001 —

.0001 ••-0001 •'•

Goor--. 0 0 0 1 -.0008-.0004—

Baselinevs week 14

.0001--

.0001 -

sbrinkage of the gingival tissues attributable to con-itolled oral bygiene'^ would equally effect all quad-rants and was observed in all groups.

Tbe length of the observation period in a trial de-pends on the procedure as well as the agent being test-ed. The present study compared an antibiotic (metro-nidazole) and the effect of scaling. Studies utilizingElyzol have a 3- to 6-month observation period.Morisson et al- '' estimated elinical healing after sealingand root planing after 4 weeks, while Badersten et al-'-'studied 15 patients with advanced periodontitis andreported that healing was not completed until after 4 to5 months po.stscaling. The differences in results tnaybe attributed to differences in instrumentation, scaling,trauma, severity of the disea.se, systemic factors, ete.

The results of various treatments on probing depthwere analyzed in two ways; (I) analyses of the pooleddata based on the mean probing deptb per treated quad-rant and patient and (2) analyses of tbe effect on shal-lower and deeper pockets. Analysis of the effect on theprobing depth as mean pooled data and on sballowerpockets after 14 weeks sbowed reductions in probingdepth for tbe tbree treatments varying from 0.15 to 0.46mm and a reduction of 0.04 mm for the control. Thesechanges are within the intraexaminer's ± 0.5 mm repro-ducibility range and are of questionable value.

The deeper pockets, after 4 weeks, showed probingdeptb reductions of I.I to 1.5 mm for the three treat-ments and 0.7 mm for the control—values that were allhigbiy statistically significant and similar to tboscreported by Ainamo et al''' and Sfetzel and Flores deJacoby,- ""' who found a 1.3-mm reduction in probing

deptb after Ely/ol treatment and a 1.5 mm reductionafter scaling.

Combined treated and scaled quadrants show signifi-cantly greater probing deptb reductions than did thecontrol sites. No difference in probing depth reductionwas observed between scaling and combined treatmentafter 4 weeks; thus, the effect of combined treatmentseems mostly to be the result of scaling. After 14weeks, the transient effect of Elyzol was further illumi-nated, because scaled quadrants showed significantlymore probing depth reduction than did Ely^ol-treatedquadrants.

The striking difference observed in tbe probing depthreduetions between deeper pockets and shallower pock-ets, and the mean PD, is not unexpected, because moreshrinkage occurs in deeper pockets than in sballowerpockets."-""' The finding that scaling alone and com-bined treatment resulted in greater PD reduction tbandid Elyzoi alone, is not in agreement witb results report-ed by Klinge et al," Pedrazzoli ct al.-"' Ainamo et al,'-*Stetzel and Flores de Jacoby,-'" and Radvar et al.--' Tbisdifference may be explained by the present findings thatElyzol has a time-limited or transient effect. In the ptxs-cnt study, no significant differences in PD were ob-served between sites subjected to scaling and combinedtreatment. This indicates tbat there was no added benefitfrom the use of Elyzol in tbe combined treatment ofadult periodontitis. Tbis is in contrast to results reportedby Mubarik, who claims tbat "an additional effect onperiodontal bealth can be obtained by a combined ther-apy," as a 2- to 3-mi-n reduction in probing deptb and aI- to 3-mm gain in tbe probing attacbment level were

46 Volume 29, Number 1

Awartani/Zulqarnain

obtatned in a short time (.1-month study] iMubarik S.persotial communication. 1995),

The present tmding that scaling was statistically siy-niftcantly more effective than Elyzol atone in reducingdeeper pockets is in agreement with the results reportedby Loesche et al.-'' Joyston-Bechal et al,-" and Walsh.-'-who fotind similar trends when metronida;^ole was ad-ministered systemically.

The three active treatment methods showed similartrends in PI up to week 6. Thereafter, while scaling andcombined treatment had a sustained effect, the Elyzolquadrant showed a sudden tncrease in PI. and at week 14it became similar to the control quadrant. This indicatesthat the reduction in Plaque Index in Elyzol-treatedquadrants is due mainly to itiiproved oral hygiene andthat the effect is transient. The transient effect of topical-ly applied 25% Elyzol dental gel noted in the presentstudy was also noted by Walsh et al,-"- who noticed anincrease in PI following the initial reduction. I monthafter systemic administration of 250 mg metronidazole.

The Gingival Index declined for all treatment groupsand the control sites, Elyzol-treated quadrants, however,exhibited an increase in GI atter 6 weeks, mirroring theincrease in PI. Scaled and combination treatment quad-rants did not show any difference in Gl. but bothshowed significantly greater reduction in Gl than didElyzol-treated sites. The numerical difference was.however, no mote than 0.3 mean units, which is of noclinical importance.

The BOP values, indicating the reduction of in-tracrevicular irritants, were highly significantly reducedft)r all three treattnent quadrants and the control quad-rants up to week 14. The reduction in BOP for the con-trol sites is intriguing, because subgingival plaque andcalculus were not removed. However, the results mightbe explained as an overlapping effect of Elyzol. The factthat scaling and combined treatment were superior toElyzol treatment in reducing the BOP indicates thatmechanical treatment was the effective part, whileElyzol was effective during the first 4 weeks. The pres-ent results are not in agreement with those of Pedrazzoliet al."' who reported that Elyzol gel "tended to be betterthan scaling'" in reducing the percentage of sites withbleeding, during a 24-week study period. The reason forthese divergent results could be differences in scalingprocedures and protocol or in Ely/ol application andretention. Clearly, deeper pockets would actually receivea greater amount of the gel.

The multicenter study hy Ainamo et al'-* reportedthat, statistically, scaling reduced BOP more than Elyzoldid. This reduction was considered to be clinicallyunimportant, Mubarik (personal communication, 1995)found that, in the treatrTient of adult patients with tntid-

erate-to-severe periodontitis, Ihe simultaneous use ofscaling and Elyzol was more effective in reducing BOPand PD than either of the treatments alone, causing again in prtthing attachment level of I to 3 mm. He didnot find any statistically significant difference hetweensealed and Elyzol-treated pockets, which is in contrastto the present findings. For now, the explanation isunknown, for example, differences in the material con-cerning probing depths, differences in registration, etc.The depth of probe penetration depends on probingforce, diameter of the probe tip. the inflammatory statusof the tissues at the start of the study, and the placementof the probe, including its angulation,-"'*''These factorsmay also explain differences in results. The use of aconstant-force probe (25-g load using a Florida probe)enhances the value of the present results. One reasonthat the results for PD and BOP findings were differentfrom those teported by Ainamo et al,'^ Klinge et al.'-'and Stetzel and Elores de Jacoby-"' is that their sampleshad p. higher mean PD (5,8 and 5,6 mm) than did thepresent patients (4,58 and 4.62 mm) for Elyzol-treatedand scaled quadrants, respectively.

For the future, long-term controlled clinical trialsshould be undertaken to study the benefits of the poten-tial immediate transient effect of Elyzol on acute peri-odontal diseases such as periodontal abscesses and inpatients with persistent active pockets that are refractory,

AcknoHledgnicnt

Tliis paper is based on ii ihesis submitted by Dr AwartnnI lor a mas-ter's degi-ee ai King Sajd University, Riyadh.

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nuintessence Inlernalional 47

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Volume 29, Number 1, 199g