implants - international magazine of oral implantology

industry report I local treatments were performed, based upon the re- call interval. If there was a recurrence of minor in- flammationaroundanimplant,theantibacterialperi- odontaltreatmentwasrepeated. _Statistical methods Astatisticalsoftwarepackage(SPSS)wasusedfor thestatisticalanalysis.Statisticalsignificancewasde- finedbyap-valueof<0.05.AchangeinPPDwasde- finedastheprimaryoutcomemeasure.Thesecondary outcome measure was a change in bone height. The data was also analyzed using independent t-tests for continuousvariableswithanormaldistribution(equal variance not assumed; PPD, changes in bone height) and using the Mann-Whitney U-test for non- para- metricdata(BoP,suppuration)andachi-squaredtest. _Results Atbaseline,apointofbleedingwasfoundat4.2% of all implant surfaces, a line of blood at 47.6% and a drop of blood at 56.9% of the sites. Statistical analy- sis failed to demonstrate baseline differences in BoP between different implant surfaces (p = 0.85). At six months,noevidenceofbleedingwasfoundin81%of the implants in the LAS group and in 59% of the im- plantsintheCMTgroup.ThedecreaseinBoPwassig- nificant in both study groups (p<0.001). Statistical analysis demonstrated differences in changes in BoP between the study groups (p<0.001). The mean PPD reductionintheCMTandLASgroupswas0.8mm(SD ± 0.5) and 1.7mm (SD ± 1.3), respectively, with mean changesinboneheight(loss)of-0.5mm(SD±0.6)and -0.1mm (SD ± 0.2), respectively (S) (Table 2). The pro- portional changes in bone height between baseline and six months, assessed from radiographs and de- fined at the implant level, are presented in Table 3. A positivetreatmentoutcome,PPDreductionof>4mm andgainornolossofbonewerefoundin59%ofthe CMT and 81% of the LAS groups, respectively (S). All subjects completed the study, and no implants were lost. _Discussion Inmodernoralimplantology,lasershaveaconsid- erable spectrum of clinical application. The literature data revealed that different laser wavelengths are used on peri-implant tissues: treatment of peri-im- plant mucositis, treatment of infrabony defects, re- movalofperi-implanthyperplasticovergrowthtissue, preparation of bone defects for GBR.3,4,22,28,29 Unlike mechanicaldecontaminationmethods,whichcannot fullyadapttotheirregularitiesonthesurfaceofanim- plant,laserscanirradiatethewholesurface,reaching areasthataretoosmalltoreceivemechanicalinstru- mentation. Recent in vivo studies have analyzed the outcome of peri-implantitis treatment using Er:YAG lasers1,21,27,31 andCO2 laser.3,28,29 Manyofthesestudies showed promising short-term results (less than six months), but report no long-term follow up. In the present study, differences in the reduction of BoP six monthsaftertreatmentwerefoundbetweenLASand CMTgroups.Whileoralhygienehadimprovedgreatly and no plaque was found at the treated implants, a large proportion of the im- plants in the CMT group con- tinuedtoexhibitBoPatthesix- monthpost-treatmentassess- ments. In the present study, BoP was graded to distinguish the severity of inflammation andapproximately14%ofthe implantsintheLASand41%in theCMTgroupspresentedwith bleeding,whichwasconsistent with other data.30 The reason- able explanation for these re- sults is the quality of deconta- minationoftheimplantsurface provided by the treatment ap- proaches evaluated. Contami- nantssuchasbacteriaandtheir by-products, calculus, and granulations should be re- moved without modifying the Table 1_Tips and settings used during laser treatment. Table 2_Proportional changes in PPD between baseline and six months, defined at the implant level based on the mean value of changes at four sites/implant. Procedure Hard tissue/ soft tissue Contact/ non-contact Laser energy (mJ) Pulse frequency (Hz) Tip diameter x length (mm) Waterspray level Releasing incision of the flap Soft tissue Contact 200 35 0.4 x 17 5–6 Granulation tissue ablation Soft tissue Non-contact 400 17 1.3 x 14 6 Bone remodelling Hard tissue Non-contact 300 25 1.3 x 19 8 Implant decontamination Hard tissue Non-contact 150 45 1.3 x 17 6 Decortication for GBR technique Hard tissue Non-contact 300 25 1.3 x 19 8 I 33implants3_2013 PPD changes CMT (%) LAS (%) Decrease (mm) > 4 1.2 37.4 3.1–4.0 7.9 35.0 2.1–3.0 14.0 7.9 1.1–2.0 35.4 12.1 0.1–1.0 1.7 4.2 Unchanged (mm) 0.0 29.2 1.4 Increase (mm) 0.1–1.0 7.9 0.0 1.1–2.0 1.2 0.0 2.1–3.0 1.0 0.0 3.1–4.0 0.0 0.0