Periodontitis is a multifactorial inflammatory condition associated with an oral microbiome dysbiosis that results in gingival inflammation and clinical attachment loss. Periodontal therapies are based on scaling and root planing to disturb the bacterial biofilm mechanically and remove calculus and contaminated cementum. Research does not support the use of root modifiers for decontamination and biomodification of periodontally affected root surfaces. Standardized clinical trials in large populations, assessing biological and patient-reported outcome measures, are necessary to evaluate candidate biomaterials for decontamination and biomodification of periodontally affected root surfaces.
Root modifiers do not provide clinical benefits for decontamination and biomodification of periodontally affected root surfaces.
The use of enamel matrix derivative might improve clinical outcomes after the surgical treatment of deep intrabony defects.
Standardized clinical trials in large populations, assessing biological and patient-reported outcome measures are necessary, to evaluate candidate biomaterials for decontamination and biomodification of periodontally affected root surfaces.
Periodontitis is a multifactorial inflammatory condition associated with an oral microbiome dysbiosis that results in clinical attachment loss. Nonsurgical and surgical therapies have been used to treat periodontitis, focusing on stopping further attachment loss and reestablish the clinical health condition. Scaling and root planing (SRP) is applied to all periodontitis cases to disturb the bacterial biofilm and remove calculus and any contaminated cementum. , Debridement of root surfaces using hand instruments or ultrasonic scalers results in a variated range of damage to the root surface. The root surface may also be exposed after debridement, and this factor may jeopardize future periodontal regeneration procedures.
The periodontal wound healing regeneration starts with the blood clot that functions as a matrix for the migration of inflammatory cells such as neutrophils and monocytes. This cascade of cellular events involves migration, adhesion, proliferation, and differentiation of several cell populations. Thus, the decontamination and biomodification of root surfaces in combination with mechanical debridement to benefit periodontal healing is still a matter of debate. In that sense, several studies have used strategies to modify or conditionate the periodontally affected root surface to increase tissue regeneration and root coverage success rates. Chemical, mechanical, and physical strategies have been evaluated for their potential to modulate the hypermineralized surface layer and to remove the endotoxins. In general, promising results have been demonstrated in in vitro studies, although clinical trials have shown contradictory results.
Therefore, this narrative review aimed to address whether different root decontamination and/or biomodification methods could improve the periodontal regeneration of infrabone defects and root coverage. A search strategy was conducted as presented in Box 1 . The related literature of clinical studies is discussed, and the future role of these strategies in periodontal regeneration is explored.
Field 1: root surface, root surface modification, root surface biomodification, decontamination.
Field 2: tissue regeneration, intrabony defects, intrabony defects, infrabony defects, infrabony defects, intraosseous defects, intraosseous defects, vertical defects, furcation, furcation defects, furcation lesions, root coverage, periodontal defect.
Inclusion criteria: Surgical periodontal therapy, human study with periodontal clinical evaluation; sample size – 10 defects and/or teeth per group; present a negative control group (without root conditioner/root decontamination); 6-month follow-up
Exclusion criteria: in vitro studies; animal studies; case reports; histologic human reports; microbiological and immunologic studies without periodontal evaluation.
Citric acid, EDTA, Tetracycline, aPDT.
Mechanical and Physical agents:
Polishing, Air polishing, Washing with saline solution, SRP, and Laser.
Possible antimicrobial effects:
Emdogain, PRP, PRF.
Root surface modifier strategies to treat periodontally affected teeth
SRP can decrease and disturb the organization of bacterial dental biofilm and the cytotoxic substances contained in the calculus and cementum on root surfaces of periodontally diseased teeth. However, these procedures inevitably leave a smear layer that, with the remaining contaminated cementum, may negatively influence the recruiting and adhesion of periodontal ligament cells and inhibit new attachment.
Earlier studies performed in the 1980s and 1990s evaluated the smear layer removal etching the denude root dentin and some portions of cementum with tetracycline hydrochloride, citric and phosphoric acids as well texapon detergent ethylenediaminetetra-acetic acid (EDTA). These modifiers also exposed dentinal tubules and reduced the endotoxins into the cementum. However, acidic modifiers resulted in a necrotizing effect on the surrounding tissues compared with EDTA treatment with a neutral pH and calcium chelator. This chelating agent also preserved the integrity of exposed collagen fibers, early cell colonization, and vitality of adjacent tissues. In addition to etching chemical substances, some elegant reviews , showed that treated root surface by physical methods as laser and antimicrobial photodynamic therapy (aPDT) demonstrated better attachment of the regenerated periodontal tissues. erbium-doped yttrium-aluminium-garnet (Er:YAG) and erbium, chromium-doped yttrium-scandium-gallium-garnet (Er,Cr:YSGG) were used to improve the capability to remove and to conditioned the contaminated root surface for periodontal tissue regeneration.
Several attempts have been made to enhance regeneration outcomes by combining/adding root modifiers and membranes and/or barriers, as presented elsewhere in this article.
Root surface modifier strategies to improve clinical outcomes of periodontal surgeries
The multifactorial etiology of periodontitis and the several local and systemic risk factors associated with this disease makes periodontal tissue regeneration is a challenging task. Anti-infective and regenerative procedures have been evaluated in several investigations for their capacity to remove as much as possible the contaminated cement and endotoxins. The ultimate goal of these studies were to assess the potential of these procedures to modulate the regeneration of the lost periodontal tissues ( Table 1 ).
|Study (Year)/Root Modifier||Study Design||Follow-up Period (mo)||No of Treated Tooth/No. of Treated Participants||Methodology||Clinical Outcomes||Conclusion|
|Parodi & Esper (1984)/citric acid||Case control||6||20 lower molars with furcation involvement divided in test (topically applied citric acid) and control (saline solution)/there was no mention for number of patients||After 30 d of non-surgical periodontal therapy, the molars were divided in test (citric acid) and control (saline solution) and surgical periodontal procedures were performed in both groups. Clinical parameters were taken at pre-baseline, baseline, 3, and 6-mo postoperatively. Reentry was performed at 6 mo to measure bone level.||
||The use of citric acid presented a “weak” beneficial effect in the furcation-involved human molars.|
|Smith et al, 1986/citric acid||Randomized||6||120 teeth/10 participants with severe periodontitis||Teeth were divided in test (citric acid) and control (saline solution). Each are must present ≥2 teeth from second molar to cuspid, with PD ranged from 1 to 13 mm.
Surgical access using modified Widman flap to scaling and root planning. The participants were included in a maintenance control during 2-, 4-, and 6-wk postsurgical for professional control.
||The citric acid did not clinical evidence of improve or accelerate periodontal healing during modified Widman flap surgery. CAL demonstrated similar patters for the groups in both shallow and moderate/deeper pockets.|
|Moore et al, 1987/citric acid||Double-blind, controlled clinical trial on a split-mouth design||9||There was no mention for number of teeth/12||12 participants received initial periodontal therapy including oral hygiene instruction, SRP, and after a minimum period of 8 wk. Follow the initial therapy, 10 participants were included: present at least a pair of sites (except molars) with PD > 5 mm receive periodontal surgery with adjunctive procedures: Test (citric acid with pH = 0.6) and control (saline solution). The participants also received penicillin and chlorhexidine 0.2%.||
||This study showed that 75% and 60% of experimental sites gain attachment at 3 and 9 mo irrespective of the treatment group. In addition, there was no statistical difference in all clinical parameters in the group of root surface etching with or without citric acid during flap surgery.|
|Kersten et al, 1992/citric acid||Randomized clinical study||12||26 intrabony defects/23||Defects with proximal residual PD ≥ 6 mm and intrabony defects ≥4 mm; the defects were surgically treated with test – citric acid and ePTFE and control – ePTFE without acid etching||
||The ePTFE barrier was effective to treat the defects irrespective the use of citric acid.|
|Fuentes et al, 1993/citric acid||Clinical study||12||27 furcation defects/16||Patients with ≥1 mandibular molar with buccal class II furcation defect with horizontal PD >3 mm; Surgical treatment included coronal flap positioning with citric acid (test) or without (control).||
||Although a slight clinical improvement was associated with citric acid group without statistical significance, etching root surfaces may be not be “necessary part” of this procedure.|
|Machtei et al, 1993/tetracycline HCl||RCT||12||36 furcation defects/18||Class II furcation involvement of the mandibular first or second molars were surgically treated with ePTFE; defects were treated with tetracycline HCl (test) or saline solution (control).||All clinical parameters were improved after treatment in both groups ( P >.05).
Tetracycline saline ΔPD 3.12 ± 1.5 3.16 ± 1.6
Microbiological differences were not detected between groups; however, Actinobacillus actinomycetemcomitans was detected in 5 sites during the monitoring phase and was associated with less favorable clinical results.
|Anti-infective therapy and monitoring for A actinomycetemcomitans and/or other periodontal pathogens might be useful in guided tissue regeneration; tetracycline HCl did not improved the periodontal parameters.|
|Mayfield et al, 1998/EDTA||CCS||6||36 interproximal intraosseous defects/36||3 mo after of hygienic treatment phase:
Test group: access flap procedure + root conditioning with EDTA gel for 3 min followed by copious irrigation with sterile saline.
Control group: access flap procedure
||EDTA gel did not provide additional benefits to flap surgery in the treatment of periodontal intraosseous defects.|
|Issa et al, 2019/PBM-SMV-EDTA||RCT||9||40 periodontal defects/40||4 wk after of hygienic treatment phase:
Group 1: OFD, 1.2% SMV gel followed by defect coverage with OM.
Group 2: OFD, 1.2% SMV gel, and defect coverage with PBM.
Group 3: OFD, 24% EDTA root surface etching, 1.2% SMV gel, and coverage of the defect with OM.
Group 4: OFD, 24% EDTA root surface etching, 1.2% SMV gel, and defect coverage with PBM.
||PBM-SMV-EDTA combination therapy seemed to be a promising regimen in treating periodontal defects. SMV availability seemed to be enhanced after the use of EDTA root surface etching.|
|Cortellini et al, 2007/EMD||COS||12||13 intrabony defects/13||3 mo after of hygienic treatment phase: MIST + EMD||PPD BL: 7.7 ± 1.8
PPD 12M: 2.9 ± 0.8
REC BL: 1.0 ± 1.5
REC 12M: 0.9 ± 2.1
CAL BL: 8.7 ± 2.7
CAL 12M: 3.8 ± 2.2
|MIST associated with EMD is effective in the treatment of isolated deep intrabony defects.|
|Aslan et al, 2017/EMD||COS||12||12 deep intrabony defects/12||3 mo after of hygienic treatment phase: EPP technique + 24% EDTA gel for 2 min + EMD||PPD BL: 9.7 ± 3.0
PPD 12M: 2.7 ± 0.7
REC BL: 2.5 ± 1.3
REC 12M: 2.66 ± 1.5
CAL BL: 12.2 ± 3.6
CAL 12M: 5.4 ± 2.0
|EPP technique and 24% EDTA and EMD resulted in enhanced clinical outcomes in deep intrabony defects without any soft tissue complication|
|Cosgarea et al, 2021/air polishing||RCT||12||A total of 27 teeth (n = 14 test and n = 13 control)/30 patients with periodontitis stages III and IV were included at baseline; 27 participants were evaluated at 12 mo: n = 14 test and n = 13 control groups
Smokers were also included
|Single-center, examiner-masked, 2-arm parallel design
RCT pilot study to compare clinical outcomes and side effects of root surface decontamination during periodontal surgery
Test group: erythritol powder and air-polishing device (mid water and power settings for 10 s; Air-Flow Master with Perio-Flow System, EMS, Nyon, Switzerland)
Control group: flap debridement using conventional hand and ultrasonic instruments
|Primary outcome variable was CAL gain, with the patient as unit. Secondary endpoints were
mean changes in FMPS, bleeding on probing, GBI, PD, decrease in the PD, CAL-, BS- (ΔBS) and BL-gain (ΔRBL) at 12 mo.
All parameters decrease at 6 and 12 mo after therapy for both groups ( P >.05);
Reductions after 12 mo
|Air polishing with an erythritol powder during periodontal surgery may represent a valuable minimally invasive adjunct following calculus removal by means of hand and ultrasonic instruments or a valuable alternative to these, for root surfaces without calculus.|
|Clem et al, 2020/Er, Cr:YSGG||RCT||6||79 intrabony defects/53||Multicenter, blinded study; patients with generalized periodontitis stage III, grade B; ≥1, but up to 2, nonadjacent teeth PD ≥6 mm and an intrabony defect with vertical dimension ≥3 mm; the defects were treated according to the group – Er,Cr:YSGG or MIST; PROs for pain, bleeding, swelling, ice pack use, anxiety, and satisfaction were also recorded.||After 6 mo period, both treatments presented similar results ( P >.05)
ΔCAL 1.26 ± 1.20 1.22 ± 1.32
ΔPPD 1.71 ± 1.18 1.63 ± 1.22
ΔGL – 0.41 ± 0.65–0.35 ± 0.66
Er,Cr:YSGG group presented less bruising, facial swelling, and use of ice pack
|Both treatments presented similar clinical outcomes, however superior effect in PROs for the surgical treatment of intrabony defects.|
|Karthikeyan et al, 2019/diode||RCT||6||40 quadrants/20 patients||Patients with generalized chronic periodontitis PD ≥ 5 mm; 30% of sites with 3 ≤ CAL ≤ 5 mm;
6 teeth per quadrant
Treatment groups: Kirkland flap surgery and DL-assisted open flap debridement (test) and Kirkland flap surgery (control). Microbiological test for the pathogens from red complex were also evaluated.
||Diode laser associated with Kirkland flap showed better clinical improvements than control group.|
|Martins et al, 2017/aPDT||RCT||5||20 patients (unit of analysis)||Patients with interproximal attachment loss involving ≥2 contralateral teeth with PD ≥5 mm, CAL ≥5 mm and bleeding on probing.
The defects were treated with flap debridement and aPDT (test) and flap debridement (control).
Microbiological evaluation using DNA–DNA checkerboard hybridization.
||Flap debridement associated with a single episode of aPDT presented beneficial results for the periodontal treatment.|
|Dilsiz et al, 2010/Nd:YAG + EMD||RCT/split mouth design||12||41 intrabony defects/21||Intrabony defects without furcation involvement in each of 2 contralateral quadrants; PD ≥ 6 mm and depth of the defect component >3 mm.
Defects were divided in test (Nd:YAG and EMD) and control (EMD) groups
||Nd:YAG laser root conditioning did not improve the outcome of EMD|
|Sculean et al, 2004/Er:YAG||RCT||6||23 defects (Test n = 12; Control n = 11)/23||Intrabony defect with a PD ≥ 6 mm at interproximal sites; intrabony component of ≥3 mm as detected on radiographs.
Defects were divided in Test (Er:YAG) and Control (flap debridement)
||Er:YAG laser did not improve the clinical outcomes.|
|Schwarz et al, 2003/Er:YAG and EMD||RCT||6||42 intrabony defects/22||Intrabony defect with a PD ≥ 6 mm at interproximal sites; intrabony component of ≥3 mm as detected on radiographs.
Defects were treated with EMD associated (test) or not (control) with Er:YAG
||Both therapies led to short-term improvements of clinical parameters, however, Er:YAG laser did not add additional benefit to the treatment.