Efficacy of Chemical Root Surface Modifiers in the Treatment of Periodontal Disease. A Systematic Review

Root surface biomodification in periodontal therapy: Biological rationale and clinical applications

Regenerative periodontal therapy aims to form new cementum, periodontal ligament, and alveolar bone, all sealed by gingival tissue. The root surface acts as the wound margin during this regeneration process. Root surface biomodification (root conditioning/root decontamination), therefore, seems instrumental in promoting surface decontamination and enhancing tissue attachment by removing the smear layer, exposing collagen fibrils, and facilitating blood clot formation and stabilization. This review attempted to provide an all-encompassing, evidence-based assessment of the role of root surface biomodification in regenerative periodontal therapy, particularly in intrabony defects, furcation defects, and root coverage procedures. The reviewed evidence suggested that root conditioning agents, whether used independently or in conjunction with bone graft materials, biological agents, membranes, or connective tissue grafts, do not offer any clinical advantage regarding clinical attachment gain. Thus, integrating chemical methods with the mechanical root instrumentation process does not necessarily contribute to superior clinical outcomes.

Successful management of gingival recession with creeping attachment: A case report

Key Clinical Message

A successful management of a mandibular recession with creeping attachment using free gingival graft. This case highlights the "wait-and-see" approach in the treatment plan, emphasizing the root coverage.

Abstract

This clinical report describes the case of a 23-year-old female patient with gingival recession of the mandibular left central incisor. The patient's symptoms included hypersensitivity and cosmetic improvements. After thorough examination, the patient was diagnosed with plaque-induced gingivitis on a reduced periodontium with acquired mucogingival deformities. Gingival recession was classified as Miller class II or Cairo Recession Type 1. The treatment plan consisted of a nonsurgical phase, followed by a surgical phase using a free gingival graft. The surgical procedure involved harvesting the graft from the palatal mucosa and placing it in the recipient site. Post-operative care and instructions were provided and a comprehensive follow-up schedule was established. At the 12-month evaluation, the patient exhibited healthy periodontal conditions with creeping attachment and complete root coverage. The success of the treatment approach demonstrates its effectiveness in addressing hypersensitivity and cosmetic concerns, while improving periodontal health. Factors influencing the achievement of creeping attachment are discussed, including recession width, graft position, bone support, tooth position, patient hygiene, graft thickness, and root surface treatment.

Assessment of the Smear Layer Removal Efficacy of Three Different Agents on Periodontally Compromised Tooth: An In Vitro Study

AIM

The purpose of the present study was to evaluate the smear layer removal efficacy of three various agents on periodontally compromised tooth.

MATERIALS AND METHODS

The current study included 75 molar teeth that were extracted due to periodontal disease. After that, 25 samples were randomly assigned using a simple random technique to the three different agent groups, group A: Scaling and root planing (SRP) and application of SofScale agent, group B: SRP and application of QMix agent, group C: SRP and application of MTAD agent. Using a diamond circular saw, the treated portions were divided into horizontal and vertical halves. All samples were viewed under Scanning Electron Microscope. Every tooth was focused at the coronal third, middle third, and apical third portion with a magnification of 1000×. Data were recorded and statistically analyzed.

RESULTS

The smear layer removal efficacy was more in the QMix agent (3.06 ± 0.04) group followed by MTAD agent (3.28 ± 0.09) and SofScale agent (4.14 ± 0.10) group on the root surface. On intra group comparison, there was a statistically significant difference found in all the intra group agents with all the three levels. On inter group evaluation, at coronal third, there was no significant difference found between the different agents. There was a significant difference found between the different agents at middle and coronal third.

CONCLUSION

On conclusion, the current investigation found that, the root surfaces treated with QMix shown a greater ability to remove smear layers compared to tooth surfaces treated with MTAD and SofScale agent.

CLINICAL SIGNIFICANCE

Conventional therapies such as SRP effectively eliminate calculus, plaque, and necrosed cementum; nevertheless, they leave behind a smear layer that could impede normal healing. In an effort to overcome this, root conditioning agents were applied on the root surface to remove the smear layer. The traditional root conditioning agents such as citric acid have certain disadvantages, though, such as an acidic pH that could harm the root surface. As a result, researchers have been looking for biocompatible root conditioning treatments that are more effective. How to cite this article: Singh DK, BS Raj H, Soans CR, et al. Assessment of the Smear Layer Removal Efficacy of Three Different Agents on Periodontally Compromised Tooth: An In Vitro Study. J Contemp Dent Pract 2024;25(2):156-159.

A Local Desiccant Antimicrobial Agent as an Alternative to Adjunctive Antibiotics in the Treatment of Periodontitis: A Narrative Review

Periodontitis is one of the most common oral polymicrobial infectious diseases induced by the complex interplay between the altered subgingival microbiota and the host’s dysregulated immune-inflammatory response, leading to the initiation of progressive and irreversible destruction of the periodontal tissues and eventually to tooth loss. The main goal of cause-related periodontal therapy is to eliminate the dysbiotic subgingival biofilm in order to arrest local inflammation and further periodontal tissue breakdown. Because, in some cases, subgingival mechanical instrumentation has limited efficiency in achieving those goals, various adjunctive therapies, mainly systemic and locally delivered antimicrobials, have been proposed to augment its effectiveness. However, most adjunctive antimicrobials carry side effects; therefore, their administration should be precociously considered. HybenX® (HY) is a commercial therapeutical agent with decontamination properties, which has been studied for its effects in treating various oral pathological conditions, including periodontitis. This review covers the current evidence regarding the treatment outcomes and limitations of conventional periodontal therapies and provides information based on the available experimental and clinical studies related to the HY mechanism of action and effects following its use associated with subgingival instrumentation and other types of dental treatments.

Efficacy of rh-PDGF-BB and Emdogain with or without DFDBA using M-MIST in the treatment of intrabony defects

Background

The versatile combination of emdogain or enamel matrix derivative (EMD), recombinant human platelet-derived growth factor-BB (rhPDGF-BB), and demineralized freeze-dried bone allograft (DFDBA) has not been utilized in the treatment of intrabony defects yet.

Aim

The present study attempted to investigate the efficacy of a combination of simple, uncomplicated nature of modified minimally invasive surgical technique (M-MIST) with EMD, rhPDGF-BB, and DFDBA in the surgical management of intrabony defects and to assess the possible favorable effects for a period of 6 months.

Patients and Methods

Thirty healthy subjects were included in the present double-blind, randomized controlled, two-arm parallel study. The test group was treated with M-MIST by using rhPDGF-BB, EMD, and DFDBA, and the control group was treated with M-MIST by using rhPDGF-BB and EMD.

Results

Differences between the mean values of primary clinical parameters including relative attachment level, probing depth, and gingival recession at baseline and those at 6 months after surgery were statistically significant in both groups. Inter-group comparison for clinical attachment level gain, probing depth reduction, and change in the position of gingival margin revealed no statistically significant differences. Inter-group comparison revealed significant differences in linear bone growth (LBG) and percentage bone fill (% BF) but no significant differences in the residual defect depth and change in the alveolar crest position.

Conclusion

The additional use of DFDBA provides superior benefits in terms of LBG and % BF in intrabony defects. This improvement might be attributed to the use of an osteoinductive scaffold.

Comparative Evaluation of Fibrin Network Formation after Root Conditioning using Erbium, Chromium-Doped Yttrium Scandium Gallium and Garnet Laser, Ethylene-Diamine-Tetra-Acetic Acid, and Tetracycline on Dentin: A Scanning Electron Microscopic Study

Context

Regeneration of periodontal tissues depend on the adhesion and development of fibrin clots to the root surface. Demineralization of the root surface ensures removal of smear layer uncovering dentin tubules and collagen matrix. Root conditioning agents were introduced to remove the smear layer and enhance the adhesion of blood components.

Aims

The aim of the study was to determine the effect of erbium, chromium-doped yttrium, scandium, gallium and garnet (Er, Cr: YSGG) laser on smear layer removal (SLR) and fibrin network formation when compared to tetracycline, and ethylene-diamine-tetra-acetic acid (EDTA) for periodontal regeneration.

Settings and Design

The study was conducted at Amrita school of dentistry and the study design involves in vitro comparative study.

Subjects and Methods

Forty dentinal sections were prepared from freshly extracted teeth that were periodontally affected. The samples were divided into four groups: Scaling and root planing (SRP), tetracycline, EDTA, and Er, Cr: YSGG laser. The samples were assessed using a scanning electron microscope and photomicrographs were taken and analyzed for removal of smear layer, blood component adhesion (BCA), and fibrin network formation.

Statistical Analysis Used

Analysis of variance test and Kruskal-Wallis test with P < 0.05 considered to be statistically significant.

Results

There was a significant difference between Er, Cr: YSGG laser, tetracycline hydrochloride, and EDTA categories when compared with SRP categories. There was no significant difference between Er, Cr: YSGG laser, tetracycline, and EDTA according to SLR scoring and BCA scoring.

Conclusions

It can be concluded that Er, Cr: YSGG laser-treated samples presented complete elimination of smear layer, formation of fibrin network, and BCA along with desensitizing effect for a better reduction in dentin hypersensitivity.

Periodontal Wound Healing and Regeneration: Insights for Engineering New Therapeutic Approaches

Periodontitis is a widespread inflammatory disease that leads to loss of the tooth supporting periodontal tissues. The few therapies available to regenerate periodontal tissues have high costs and inherent limitations, inspiring the development of new approaches. Studies have shown that periodontal tissues have an inherent capacity for regeneration, driven by multipotent cells residing in the periodontal ligament (PDL). The purpose of this review is to describe the current understanding of the mechanisms driving periodontal wound healing and regeneration that can inform the development of new treatment approaches. The biologic basis underlying established therapies such as guided tissue regeneration (GTR) and growth factor delivery are reviewed, along with examples of biomaterials that have been engineered to improve the effectiveness of these approaches. Emerging therapies such as those targeting Wnt signaling, periodontal cell delivery or recruitment, and tissue engineered scaffolds are described in the context of periodontal wound healing, using key in vivo studies to illustrate the impact these approaches can have on the formation of new cementum, alveolar bone, and PDL. Finally, design principles for engineering new therapies are suggested which build on current knowledge of periodontal wound healing and regeneration.

Efficacy and safety of P11-4 for the treatment of periodontal defects in dogs

Objectives

This study’s aim was to investigate the safety and performance of a self-assembling peptide matrix (SAPM) P₁₁-4 for the treatment of periodontal disease in a controlled pre-clinical study.

Materials and methods

Acute buccal bony dehiscence defects (LxW: 5 × 3 mm) were surgically created on the distal root of four teeth on one mandible side of 7 beagle dogs followed by another identical surgery 8 weeks later on the contralateral side. SAPM P₁₁-4 (with and without root conditioning with 24% EDTA (T1, T2)), Emdogain® (C) and a sham intervention (S) were randomly applied on the four defects at each time point. Four weeks after the second surgery and treatment, the animals were sacrificed, the mandibles measured by micro-computed tomography (µ-CT) and sections of the tissue were stained and evaluated histologically.

Results

Clinically and histologically, no safety concerns or pathological issues due to the treatments were observed in any of the study groups at any time point. All groups showed overall similar results after 4 and 12 weeks of healing regarding new cementum, functionality of newly formed periodontal ligament and recovery of height and volume of the new alveolar bone and mineral density.

Conclusion

A controlled clinical study in humans should be performed in a next step as no adverse effects or safety issues, which might affect clinical usage of the product, were observed.

Clinical relevance

The synthetic SAPM P₁₁-4 may offer an alternative to the animal-derived product Emdogain® in the future.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00784-021-04297-6.

Decontamination and Biomodification of Periodontally Affected Root Surface for Successful Regeneration: Is There Room for Improvement?

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.

Effect of 24% EDTA root conditioning on the outcome of modified coronally advanced tunnel technique with subepithelial connective tissue graft for the treatment of multiple gingival recessions: a randomized clinical trial

OBJECTIVES

To investigate effects of root conditioning with 24% ethylenediaminetetraacetic acid (EDTA) on the 12-month outcomes after treatment of multiple gingival recessions (GR) with modified coronally advanced tunnel (MCAT) and subepithelial connective tissue graft (SCTG).

MATERIALS AND METHODS

Twenty patients with 142 GR were treated (72 test sites: SCTG + EDTA and 70 control sites: SCTG). Average and complete root coverage (ARC, CRC), gain in keratinized tissue width (KTW), gain in gingival thickness (GT), root esthetic coverage score (RES), and patient-reported outcome measures (PROMs) were evaluated at 12 months post-operatively.

RESULTS

Differences between pre- and post-operative values were statistically significant only within but not between treatment modalities. At 12 months, ARC was 86.0% for SCTG + EDTA-treated and 84.6 for SCTG-treated defects (p = 0.6636). CRC was observed in 90.2% (tests) and 91.4% (controls) of all cases (p = 0.9903). Professional assessment of esthetic outcomes using RES showed highly positive results reaching the value of 8.9 in case of test sites and 8.7 for control sites (p = 0.3358). Severity of pain and swelling did not differ between sites, regardless of whether EDTA was used.

CONCLUSIONS

Test and control sites presented similarly positive outcomes related to root coverage, periodontal and esthetic parameters, and patient satisfaction and self-reported morbidity with no statistical differences between them 12 months after surgery. No significant differences in evaluated variables were observed between sites treated with and without 24% EDTA. Clinical relevance Considering the limitations of the present study, the use of 24% EDTA for root conditioning did not improve 12-month outcomes after treatment of multiple RT1 and RT2 gingival recessions with MCAT and SCTG. Trial registration ClinicalTrials.gov identifier: NCT03354104.

The concentration of citric acid as dental root conditioner influences the behavior of fibroblasts from human periodontal ligament

OBJECTIVE

This study investigated the behavior of fibroblasts from human periodontal ligament (hPLF) cultured on dental roots subjected to different protocols of citric acid conditioning.

MATERIALS AND METHODS

32 human teeth extracted due to advanced periodontal disease provided 63 radicular fragments, which were randomly divided in groups according to the treatment given to the surface: rinsing with saline solution for 90 s (C), 10 % citric acid (CA10), or 50 % citric acid (CA50). The treatments were applied during 90 s, 120 s and 180 s (n = 9). hPLF were cultured for 24, 48 and 72 h (n = 3) on the treated samples and analyzed by scanning electron microscopy (SEM) for surface area covered by cells and dentinal tubules widening.

RESULTS

Excepting group C, all the other groups showed almost complete coverage of root surface by hPLF with time. At 24 h of cell culture, the largest area of coverage was seen in the samples treated with CA10-90 (98 ± 0.89 %) at 24 h of cell culture and this difference was significant (p < 0.05) in comparison to CA10-180 (84.04 ± 5.01 %), CA50-90 (63.28 ± 12.46 %), CA50-180 (56.59 ± 8.76 %) and C (0.06 ± 0.11 %). In all the other comparisons, there was no statistically significant differences between CA10 and CA50 (p > 0.05). Cells grown on surfaces treated with CA10 were more spread and flatten than in the CA50 specimens.

CONCLUSIONS

Periodontally compromised roots surfaces conditioned with 10 % citric acid for 90 s resulted in better substrate for hPLF proliferation, in initial periods of culture than 50 % citric acid. The enlargement of the dentinal tubules did not seem to be influenced by the acid concentration.

How Tony Melcher advanced our understanding of periodontal biology and regeneration

Tony Melcher, a highly influential and forward-thinking scientist and teacher, focussed on the origins, behaviour and regulation of cells in periodontal tissues. His recent death in April 2020, has motivated us to highlight his multi-level contributions to research in biology and the dental sciences. Tony was particularly adept at recognizing the inherent instructive power of the periodontium, most notably as a model system for studying the inter-relationships between the structure, development and functions of connective tissues. Further, his mentoring of dozens of students who subsequently went on to develop their own careers in research, and his leadership in promoting collaborations in dental sciences world-wide, engendered important advances in the importance and utility of research relating to oral tissues. Here, we reflect upon his development of a large, multi-disciplinary research enterprise, the MRC Group in Periodontal Physiology at the University of Toronto and brief commentaries of those who worked with him there. We examine his early career development and then go on to consider some of his most highly cited publications and their impact on subsequent research trends.

Guided Tissue Regeneration Therapy With Bone Augmentation in a Lingual, Infrabony Osseous Defect of a Mandibular Canine

This case report describes the use of canine demineralized freeze-dried membrane allograft and cancellous bone graft material to treat an infrabony osseous defect along the lingual aspect of a left mandibular canine in a 10-year-old miniature dachshund. Postoperative examination 6 and 12 months postoperatively showed osseous integration at the infrabony defect and improvement in periodontal probing measurements.

Activation of cannabinoid receptors promote periodontal cell adhesion and migration

OBJECTIVE

Medical and recreational cannabis use is increasing significantly, but its impacts on oral health remain unclear. The aim of this study is to investigate the effects of tetrahydrocannabinol (THC), the major active component in cannabis, on periodontal fibroblast cell adhesion and migration to explore its role in periodontal regeneration and wound healing.

MATERIAL AND METHODS

The different distribution of cannabinoid receptors 1 (CB1) and 2 (CB2) was characterized in the mouse periodontium. Human periodontal fibroblast cell (HPLF) adhesion and migration was analysed by in vitro wound healing assay with and without THC. The focal adhesion kinase (FAK) signalling pathway was investigated to uncover the underlying cellular mechanism. The receptor dependency of cannabinoid effects was examined by using selective antagonists to block THC.

RESULTS

Both CB1 and CB2 were expressed in periodontal tissues but with different expression patterns. Tetrahydrocannabinol promoted periodontal cell wound healing by inducing HPLF cell adhesion and migration. This was mediated by focal adhesion kinase (FAK) activation and its modulation of MAPK activities. The effect of cannabinoids on periodontal fibroblast cell adhesion and migration was mainly dependent on the CB2.

CONCLUSION

These results suggested that cannabinoids may contribute to developing new therapeutics for periodontal regeneration and wound healing.

Guided tissue regeneration of intrabony defects with perforated barrier membranes, simvastatin, and EDTA root surface modification: A clinical and biochemical study

BACKGROUND

Perforated barrier membranes (PBM) were suggested to enhance periodontal regeneration by allowing positive charity of wanted elements from the gingival tissue side. The present study was designed to evaluate clinically and biochemically the use of PBM combined with simvastatin (SMV) gel with and without an associated EDTA gel root surface etching as a suggested option that could improve SMV availability and clinical outcomes of PBM.

METHODS

Forty patients having moderate-to-severe chronic periodontitis with 40 intrabony defects were randomly divided into four treatment groups (10 sites each). Patients in group 1 received 1.2% SMV gel and covering the defect with occlusive membrane (OM). Patients in group 2 received 1.2% SMV gel and covering the defect with PBM. Group 3 received 24% EDTA root surface etching, 1.2% SMV gel, and defect coverage with OM (eOM). Patients in group 4 were treated as in group 3 but the defect was covered with PBM (ePBM). Clinical parameters were recorded at baseline before surgical procedures and were reassessed at 6 and 9 months after therapy. The mean concentration of SMV in gingival crevicular fluid (GCF) was estimated by reverse-phase high-performance liquid chromatography at days 1, 7, 14, 21, and 30.

RESULTS

At 6- and 9-month observation periods, groups 3 and 4 showed a statistically significant improvement in PD reduction and CAL gain compared with groups 1 and 2. Group 4 showed a statistically significant more defect fill compared with groups 1, 2, and 3 (P ≤ .05). Group 2 showed statistically significant higher defect fill compared with group 1 and group 3 (P < .05). Bone density was significantly increased with no significant difference between the four groups at 6- and 9-month observation periods. SMV-GCF concentration in group 4 showed the highest mean concentration with no significant difference than that of group 3.

CONCLUSION

The use of perforated barrier membranes in association with SMV enhances the clinical hard tissue parameters compared with occlusive ones in treating intrabony periodontal defects. Moreover, EDTA root surface treatment could enhance SMV availability in the defect area.

Biodegradable Polymer Films with a Natural Antibacterial Extract as Novel Periodontal Barrier Membranes

Biodegradable composite membranes containing propolis were produced from PCL/PLLA blends using a simple and low-cost solvent casting method, and subsequently their physicochemical, mechanical, and antibacterial properties were characterized. SEM analysis revealed that the addition of propolis has created honeycomb-like structures on the film surfaces. The flexibility of the films increased in the presence of propolis, which may provide ease of use during application. Propolis disrupted the organized structure of both polymers at the molecular level and caused decreases in the melting points. The films with propolis showed faster degradation in physiological conditions due to this molecular disruption. Moreover, the PLLA/PCL/propolis composite films exhibited remarkable antibacterial activities against S. aureus. Collectively, the data suggest that the produced films might be used as an alternative to exiting barrier membranes in guided tissue regeneration.

Biomaterials, Current Strategies, and Novel Nano-Technological Approaches for Periodontal Regeneration

Periodontal diseases involve injuries to the supporting structures of the tooth and, if left untreated, can lead to the loss of the tooth. Regenerative periodontal therapies aim, ideally, at healing all the damaged periodontal tissues and represent a significant clinical and societal challenge for the current ageing population. This review provides a picture of the currently-used biomaterials for periodontal regeneration, including natural and synthetic polymers, bioceramics (e.g., calcium phosphates and bioactive glasses), and composites. Bioactive materials aim at promoting the regeneration of new healthy tissue. Polymers are often used as barrier materials in guided tissue regeneration strategies and are suitable both to exclude epithelial down-growth and to allow periodontal ligament and alveolar bone cells to repopulate the defect. The problems related to the barrier postoperative collapse can be solved by using a combination of polymeric membranes and grafting materials. Advantages and drawbacks associated with the incorporation of growth factors and nanomaterials in periodontal scaffolds are also discussed, along with the development of multifunctional and multilayer implants. Tissue-engineering strategies based on functionally-graded scaffolds are expected to play an ever-increasing role in the management of periodontal defects.

[Efficacy of minocycline hydrochloride combined with flap surgery for chronic periodontitis: a Meta-analysis]

OBJECTIVE

This study aimed to evaluate the efficacy of 2% minocycline hydrochloride combined with flap surgery in the treatment of chronic periodontitis. The superiority of this therapy to simple flap surgery was also explored.

METHODS

We searched the databases of CNKI, VIP, Wanfang, Chinese Biomedical Literature, PubMed, ScienceDirect, and Embase from inception to July 2017. Two reviewers independently screened literature, extracted data, and evaluated the bias risk of included studies. Then, Meta-analysis was performed using RevMan 5.3 software.

RESULTS

A total of seven randomized controlled trials involving 217 patients were included. Meta-analysis showed that, in two groups, the changes in probing depth (PD) [MD=-0.55, 95%CI (-0.84, -0.26), P=0.000 2] and plaque index [MD=-0.08, 95%CI (-0.15, -0.01), P=0.03] at 3 and 6 months of PD [MD=-0.62, 95%CI (-1.04, -0.21), P=0.003] had statistically significant difference (P<0.05). The clinical attachment loss (CAL) [MD=-0.21, 95%CI (-0.47, 0.04), P=0.10] had no statistically significant difference after 3 months (P>0.05), but the improvement in CAL was significantly improved by minocycline hydrochloride combined with flap therapy.

CONCLUSIONS

Periodontal flap combined with minocycline adjuvant therapy for chronic periodontitis is effective in short-term observations.

Topical application of bFGF on acid-conditioned and non-conditioned dentin: effect on cell proliferation and gene expression in cells relevant for periodontal regeneration

Periodontal regeneration is still a challenge in terms of predictability and magnitude of effect. In this study we assess the biological effects of combining chemical root conditioning and biological mediators on three relevant cell types for periodontal regeneration.

A Comparative Scanning Electron Microscopic Analysis of the Effect of QMix® and SofScale™ as an Adjunct to Scaling and Root Planing on Periodontally Compromised Root Surfaces: An In vitro Study

Aim:

This study aimed to comparatively analyze, under scanning electron microscope (SEM), the effect of the use of QMix^® and SofScale^™ as an adjunct to scaling and root planing (SRP) on periodontally compromised root surfaces.

Settings and Design:

This study was carried out in K. M. Shah Dental College and Hospital, Vadodara.

Methodology:

This was a single-blinded in vitro study which compared QMix^® and SofScale^™ as an adjunct to SRP on periodontally compromised root surfaces under SEM.

Statistical Analysis Used:

Statistical analysis was done using a nonparametric Mann–Whitney U-test to test the null hypothesis that there is no difference between the test and control groups.

Results:

The sum of ranks for QMix^® was 306.50 and the sum of ranks for SofScale^™ was 513.50. The group which was treated with QMix^® showed statistically significant results (P = 0.004) as compared to group which was treated with SofScale^™.

Conclusion:

Comparative analysis showed that QMix^® had significantly better smear layer removal ability as compared to SofScale^™. However, uniform root surface was achieved with both QMix^® and SofScale^™.

pH influences the biocompatibility of methylene blue solutions

OBJECTIVE

The aim of this study was to investigate the biocompatibility of methylene blue at different pH levels through the method of implantation in subcutaneous tissue.

MATERIALS AND METHODS

Eighty-four sterilized polyethylene tubes were allocated in the subcutaneous tissue of 28 rats, each one receiving four tubes, set into four groups: group tube (G-T)-empty tube, fibrin group (G-F)-tube filled with fibrin sponge, group methylene blue pH 7 (G-MB/pH 7)-tube filled with fibrin sponge soaked by methylene blue (100 μg/ml) at pH 7.0, and group methylene blue pH 1 (G-MB/pH 1)-tube filled with fibrin sponge and soaked by methylene blue (100 μg/ml) at pH 1.0. After 7, 15, and 30 days, seven animals from each group were euthanized, and the tubes involved by the surrounding tissue were removed and fixed with 4% buffered formaldehyde solution. The collected pieces were processed and histological sections (4 μm) were stained with hematoxylin and eosin and analyzed by light microscopy. Scores were assigned to analysis of histopathologic parameters. The results were statistically analyzed by the Kruskal-Wallis test (p ≤ 0.05).

RESULTS

At 7 and 30 days, the G-MB/pH 1 group showed no significant difference in the G-T control group, while G-MB/pH 7 had a significant increase on tissue reaction, also when compared to G-T. At 15 days, there was no statistical difference between the groups.

CONCLUSION

Within the limits of this study, it is concluded that methylene blue at pH 1.0 provides better biocompatibility than at pH 7.0.

Comparing fibroblast attachment in root surface scaling with Er, Cr:YSGG laser versus ultrasonic scaler: A SEM study

BACKGROUND AND OBJECTIVES

The regeneration of periodontal support is the main concern in periodontal therapy. The aim of this in vitro study was to investigate the fibroblasts attachment on root surfaces after scaling with Er, Cr:YSGG laser and ultrasonic instruments using scanning electron microscopy (SEM).

METHODS

72 root plates of ∼6 × 4 × 1 mm³ in dimension were prepared from 27 single-rooted human mature teeth and were then divided into four groups. One group irradiated with a G6 tip of Er, Cr:YSGG laser (2.78 µm, 0.75 W, pulse duration of 140 µs, repetition rate of 20 Hz) for 5 to 7 s, and the other groups were scaled with ultrasonic alone or laser-ultrasonic. The control group was subjected to neither laser nor ultrasonic scaling. Subsequently, Viability and proliferation rates were done using MTT assay on days 3 and 5. Finally the cell attachment was observed using SEM.

RESULTS

The data derived from MTT and cell-attachment analysis indicated that laser-ultrasonic scaling tended to increase cell-viability by the lapse of time (within 3-5 days), with significantly better cell-attachment compared with other groups on days 3 and 5 (p < .05). The comparison of the difference in fibroblast cell attachment rate on both the third and the fifth day with independent T-Test indicated a significant rise on the fifth day compared to the third day of study (p < .05).

CONCLUSION

Indeed, both Er, Cr:YSGG laser and ultrasonic scaling may promote fibroblast attachment on dentinal root surfaces more than laser or ultrasonic scaling alone.

Effect of combination of ethylenediaminetetraacetic acid + tetracycline with coronally positioned flap in the treatment of gingival recession: A clinical study

CONTEXT

Gingival recession is the apical migration of gingival margin results from destruction of the connective tissue leading to various esthetic problems. Many surgical procedures have been attempted to achieve root coverage that include free gingival grafts, pedicle flaps such as semilunar coronally repositioned flaps (SCRFs) and guided tissue regeneration. The exposed root surface has undergone substantial alterations and may no longer serve as an appropriate substrate for cell attachment and fiber development. When the denuded root surfaces are treated with biomodifiers following mechanical instrumentation, the resulting surface favors both the attachment of fibroblasts and new connective tissue attachment. It was then necessary to evaluate the surface characteristics of the acid demineralized root surface and its effect on periodontal wound healing.

AIM

To evaluate the effect of the combination of ethylenediaminetetraacetic acid (EDTA) and tetracycline as root bio-modifiers along with SCRF for root coverage.

SETTINGS AND DESIGN

Twenty subjects were randomly assigned into two groups as cases (SCRF + EDTA + tetracycline [TTC]) and controls (SCRF).

MATERIALS AND METHODS

Twenty-four percentage EDTA and 100 mg/ml TTC hydrochloride were used along with semilunar coronally positioned flap. The clinical parameters such as recession height, the width of keratinized tissue, recession width, clinical attachment level, probing depth, plaque index, and gingival index were recorded at baseline, 1 and 3 months.

STATISTICAL ANALYSES USED

The clinical parameters were compared using post-hoc test and the comparison between cases and controls was done using Mann-Whitney U-test.

RESULTS

No statistical significant difference has been observed between the groups.

CONCLUSION

It was concluded that no clinical benefit was observed after the application of a combination of 100 mg/ml TTC hydrochloride and 24% EDTA on the root surface.

Bone demineralization with citric acid enhances adhesion and spreading of preosteoblasts

BACKGROUND

Previous studies have demonstrated that bone demineralization can improve consolidation in bone grafts. The biologic mechanisms underlying this phenomenon remain unclear.

METHODS

Twelve adult male guinea pigs were used in this experiment. Forty-five bone samples removed from the calvaria of nine animals were divided in groups (n = 9) according to the time of demineralization with citric acid (50%, pH 1): 15, 30, 90, and 180 seconds and non-demineralized samples (control). Preosteoblasts (MC3T3-E1) were cultured on the bone samples for 24, 48, and 72 hours (n = 3). Fifteen samples removed from the remaining three animals were analyzed by scanning electron microscopy/energy dispersive spectrometry (SEM/EDS) after demineralization (n = 3).

RESULTS

The number of preosteoblasts increased significantly with time in all groups. The bone surface area covered by these cells increased with time, except in the control group. Intragroup differences occurred between 24 and 72 hours (P < 0.05). Samples demineralized for 30 seconds showed greater area covered by preosteoblast cells than for the other times of demineralization in all periods of cell culture (P < 0.05) without a statistically significant difference compared with 15 seconds. SEM/EDS showed diminished content of calcium (Ca) after 15 seconds of demineralization, but the Ca content increased after 180 seconds of demineralization (P < 0.05). The phosphorus (P) amount increased significantly only after 30 seconds of demineralization (P < 0.5). The sulfur (S) content was increased in demineralized samples in relation to non-demineralized ones, reaching the highest level after 90 seconds, when the difference became significant in relation to all the other times of demineralization (P < 0.05). Magnesium (Mg) content did not differ significantly between demineralized and non-demineralized samples.

CONCLUSIONS

Bone surfaces demineralized for 30 seconds increased the spreading of preosteoblasts as well as the surface area covered by these cells. Bone demineralization deserves to be studied in periodontal and maxillofacial regenerative procedures.

Growth factors and beta-tricalcium phosphate in the treatment of periodontal intraosseous defects: A systematic review and meta-analysis of randomised controlled trials

OBJECTIVE

To evaluate the effectiveness at different points in time, of recombinant human platelet-derived growth factor-BB (rhPDGF-BB) coated onto a beta-tricalcium phosphate (β-TCP) carrier compared to β-TCP alone, or to recombinant human growth/differentiation factor-5 (rhGDF-5) adsorbed onto a β-TCP scaffold in intraosseous periodontal defects.

DESIGN

A digital search for randomised controlled trials (RCTs) was conducted on MEDLINE/PubMed. The quality of reporting and the risk of bias of the included RCTs were assessed using the CONSORT guidelines and the Cochrane risk of bias tool. The difference between the means of the outcomes at baseline and at follow-up for each group was tested using the Student's t-test for paired samples. The difference between the means of the outcome changes at follow-up between groups was analysed using the Student's t-test for two independent samples. Prior to each analysis a test of homogeneity of variances (Ansari-Bradley) was performed.

RESULTS

From 11 articles assessed for eligibility, 5 RCTs were included in this review. The risk of bias was considered to be low in 2 articles, medium in 1 study and high in 2 studies.

CONCLUSIONS

In the treatment of periodontal intraosseous defects the application of rhPDGF-BB/β-TCP improved all outcomes when compared to β-TCP at 6 months follow-up. Either rhPDGF-BB/β-TCP or rhGDF-5/β-TCP seemed to provide similar results in terms of probing pocket depth (PPD) reduction and clinical attachment level (CAL) gain. The application of rhGDF-5/β-TCP resulted in a more pronounced reduction in gingival recession (GR) depth at 6 months follow-up compared to rhPDGF-BB/β-TCP.

Evaluation of an Osseous Allograft Membrane for Guided Tissue Regeneration in the Dog

Clinical application of a demineralized freeze-dried cortical bone membrane allograft (DFBMA) for treatment of intra(infra)bony periodontal pockets in dogs was evaluated. The mean pre-treatment periodontal probing depth equaled 7.2-mm. Post-treatment probing depths in all 11 cases were normal, with a mean periodontal probing gain of 5.4-mm. Guided tissue regeneration using a commercially available veterinary canine DFBMA and canine demineralized freeze-dried bone allograft (DFDBA) resulted in clinically significant periodontal attachment gains. The gain of new periodontal tissue attachment was statistically significant (P < 0.0001). The commercially available veterinary allograft products predictably increased new periodontal attachment without any identified membrane sequelae in these 11 cases.

Wound models for periodontal and bone regeneration: the role of biologic research

The ultimate goals of periodontal therapy remain the complete regeneration of those periodontal tissues lost to the destructive inflammatory-immune response, or to trauma, with tissues that possess the same structure and function, and the re-establishment of a sustainable health-promoting biofilm from one characterized by dysbiosis. This volume of Periodontology 2000 discusses the multiple facets of a transition from therapeutic empiricism during the late 1960s, toward regenerative therapies, which is founded on a clearer understanding of the biophysiology of normal structure and function. This introductory article provides an overview on the requirements of appropriate in vitro laboratory models (e.g. cell culture), of preclinical (i.e. animal) models and of human studies for periodontal wound and bone repair. Laboratory studies may provide valuable fundamental insights into basic mechanisms involved in wound repair and regeneration but also suffer from a unidimensional and simplistic approach that does not account for the complexities of the in vivo situation, in which multiple cell types and interactions all contribute to definitive outcomes. Therefore, such laboratory studies require validatory research, employing preclinical models specifically designed to demonstrate proof-of-concept efficacy, preliminary safety and adaptation to human disease scenarios. Small animal models provide the most economic and logistically feasible preliminary approaches but the outcomes do not necessarily translate to larger animal or human models. The advantages and limitations of all periodontal-regeneration models need to be carefully considered when planning investigations to ensure that the optimal design is adopted to answer the specific research question posed. Future challenges lie in the areas of stem cell research, scaffold designs, cell delivery and choice of growth factors, along with research to ensure appropriate gingival coverage in order to prevent gingival recession during the healing phase.

Periodontal Regeneration - Intrabony Defects: Practical Applications From the AAP Regeneration Workshop

Focused Clinical Question: What are important considerations for selecting a predictable regenerative surgical approach for intrabony defects? Summary: The predictable regeneration of intrabony defects remains an important goal in the management of periodontitis. Clinical and histologic evidence of periodontal regeneration has been shown for multiple regenerative therapies, including bone replacement grafts, guided tissue regeneration, and biologics, when used alone or in combination. Regenerative therapies improve periodontal health, as evidenced by gains in clinical attachment level, reductions in probing depth, and gains in radiographic bone fill. Important patient-related factors (e.g., smoking) and defect/site-related factors (e.g., defect morphology and gingival biotype) can influence the potential to achieve periodontal regeneration. The regeneration of intrabony defects generally becomes more challenging with increasing loss of height, proximity, and number of bony walls. Therefore, combination therapies may be necessary to achieve predictable regeneration. Clinical improvements after regenerative therapy can be maintained over extended periods (≥10 years) with professional maintenance at appropriate intervals and adequate home care. Conclusions: Periodontal regeneration of intrabony defects is possible using a variety of regenerative strategies. Management should be coupled with an effective oral hygiene and supportive periodontal maintenance program for long-term success.

The smear layer created by scaling and root planing is physiologically eliminated in a biphasic process

Mechanical instrumentation of the root surface causes the formation of a smear layer, which is a physical barrier that can affect periodontal regeneration. Although different procedures have been proposed to remove the smear layer, there is no information concerning how long the smear layer persists on root surfaces after instrumentation in vivo. This study assessed the presence of the smear layer on root surfaces over a 28-day period after subgingival instrumentation with hand instruments. Fifty human teeth that were referred for extraction because of advanced periodontal disease were scaled and root planed (SRP) by a single experienced operator. Ten teeth were randomly assigned to be extracted 7, 14, 21, and 28 days after SRP. Another 10 teeth were extracted immediately after instrumentation (Day 0, control group). The subgingival area of the instrumented roots was evaluated with scanning electron microscopy. Representative photomicrographs were assessed by a blinded and calibrated examiner according to a scoring system. A rapid and significant (p < 0.05, Z test) initial reduction in the amount of smear layer was observed at 7 days, and a further significant (p < 0.05) decrease was observed 28 days after SRP. Interestingly, even 28 days after SRP, the smear layer was still present on root surfaces. This study showed that the physiological elimination of the smear layer occurred in a biphasic manner: a rapid initial reduction was observed 7 days after instrumentation, which was followed by a slow process leading to a significant decrease 28 days after instrumentation.

Root Surface Bio-modification with Erbium Lasers- A Myth or a Reality??

The objective of this literature review was to critically review the evidence available in the literature regarding the expediency of erbium family of lasers for root bio modification as a part of periodontal therapy. The literature search was performed on the Pubmed using MeSH words such as "lasers/therapeutic use, scaling, dental calculus, tooth root/anatomy and histology, ultrasonic therapy". The studies were screened and were grouped as follows: those evaluating a) efficacy for calculus removal with the Erbium family of laser b) root surface changes following Er YAG and Er Cr YSGG application c) comparative studies of the Er YAG, Er Cr YSGG lasers versus conventional methods of root surface modification d) Bio compatibility of root surface following Erbium laser treatment e) Studies on the combined efficacy of laser root modification with conventional methods towards root surface bio-modification f) Studies on effectiveness of root surface bio-modification prior to root coverage procedures. In conclusion, the erbium family has a proven anti-bacterial action, predictable calculus removal, minimal root substance removal, and appears to favor cell attachment. The Erbium family of lasers appears to be a useful adjunct for the management of periodontal disease.

Endodontic irrigant as a root conditioning agent: An in vitro scanning electron microscopic study evaluating the ability of MTAD to remove smear layer from periodontally affected root surfaces

BACKGROUND

Instrumentation of the root surface, results in formation of a smear layer of organic and mineralized debris which serves as a physical barrier, inhibiting new connective tissue attachment to the root surface. The present study advocates the use of an endodontic irrigant MTAD (mixture of tetracycline, citric acid and detergent) as a root conditioning agent. The main aim of the study was to compare the root conditioning ability of an endodontic irrigant MTAD (mixture of tetracycline, acid and detergent) with 17% EDTA (ethylenediaminetetraacetic acid).

MATERIALS AND METHODS

Sixty freshly extracted human single rooted teeth with confirmed periodontal involvement were selected for this study and decoronated. The apical third of each root was removed and the remaining root was sectioned longitudinally to produce a 6mm to 8mm long tooth section. The root surface was then instrumented by hand using a sharp Gracey 1-2 periodontal curette with 6-8 strokes per area to achieve a smooth glass-like surface. A total of 60 specimens were prepared which were randomly divided into three groups (n=20). Each group received the root conditioning treatments as follows: All specimens were prepared for SEM and scored according to the presence of smear layer.

RESULTS AND CONCLUSIONS

MTAD removed the smear layer successfully from the root surfaces. The mean smear score for samples treated with Biopure MTAD was lower than those treated with EDTA, (p=0.04). MTAD can be used as a root conditioning agent with efficient smear layer removal ability and known antimicrobial and anticollagenase activity.

Fluorosed fibroblast attachment on fluorosed and nonfluorosed teeth after SRP and EDTA root biomodification

BACKGROUND

Fluorosis causes mineralization changes in the tooth and can lead to morphologic alterations of fibroblasts. To understand the effect of fluorosis on periodontal healing, the initial step during healing, such as fibroblast attachment to the root surface, needs to be evaluated. Hence, the objective of the present study was to study the attachment of fluorosed fibroblasts on the fluorosed and nonfluorosed root fragments.

MATERIALS AND METHODS

A total of 56 fluorosed and nonfluorosed, periodontally healthy and diseased tooth roots were obtained and allotted to eight groups: Fluorosed and nonfluorosed healthy controls (FH and NFH, respectively), fluorosed and nonfluorosed diseased controls (FD and NFD, respectively), fluorosed and nonfluorosed roots treated with scaling and root planing (FD + S and NFD + S, respectively), and similar groups treated with scaling and root planing and 24% ethylenediaminetetraacetic acid (EDTA) gel application for 2 min (FD + SE and NFD + SE, respectively). After the respective treatment, the root fragments were incubated in the human periodontal ligament fibroblast cells obtained and cultured from freshly extracted healthy human fluorosed premolar tooth root.

RESULTS

In the nonfluorosed roots category, greater attachment was found in the untreated nonfluorosed diseased (P = 0.036) and SRP-treated nonfluorosed diseased groups (P = 0.008) as compared to the nonfluorosed healthy group. While in the fluorosed roots category, no significant difference was observed in FL-FA (P > 0.05) within the group. However, no attachment was observed in EDTA-treated fluorosed root fragments. When fluorosed groups were compared to nonfluorosed groups, no significant changes were noted between the groups.

CONCLUSION

SRP proves to be a standard requirement for fibroblast attachment to occur both in fluorosed and nonfluorosed roots. Although there was no significant difference in attachment between SRP and SRP + EDTA among fluorosed roots, EDTA does not seem to be a promising agent for root biomodification in fluorosed roots in a given concentration and time of treatment.

Early root surface colonization by human periodontal ligament fibroblasts following treatment with different biomaterials

OBJECTIVES

The present in-vitro study examined the effects of different biomaterials on early root surface colonization by human periodontal ligament (PDL) fibroblasts using confocal-laser-scanning-microscopy (CLSM).

MATERIALS AND METHODS

Fifteen periodontally-diseased teeth were extracted, treated with scaling/root planing and longitudinally cut to obtain 30 root fragments. Fragments were treated either with 24% EDTA following application of enamel matrix derivative (EMD), 24% EDTA or EMD only, nanocrystalline hydroxyapatite (NHA) paste or oily calcium hydroxide suspension (OCHS) for 1 h each. The analogue untreated root specimens served as controls. Root fragments were incubated with human PDL fibroblasts and cellular proliferation and morphology were evaluated after 1, 3, 5 and 8 days using CLSM-visualization and image recognition software.

RESULTS

The rate of cellular proliferation was different among treatment modalities examined (p = 0.019). Except treatment with NHA paste all treatment modalities improved cellular proliferation on root surfaces at all different points of time compared with the control specimens. A significant difference between treatment modalities was observed between EMD and NHA paste (p = 0.008). No synergistic effect could be demonstrated comparing root surface conditioning with 24% EDTA and EMD application compared to 24% EDTA or EMD application only.

CONCLUSION

The present results suggest that initial root surface colonization by PDL fibroblasts may be enhanced by root surface conditioning with 24% EDTA and application of EMD, application of 24% EDTA or EMD alone and OCHS. The addition of 24% EDTA for root surface conditioning prior to EMD application provided no synergistic effects in terms of early root surface colonization by PDL fibroblasts.

Effects of citric acid and EDTA on periodontally involved root surfaces: a SEM study

AIM

Root debridement by scaling and root planing may not completely remove contaminated cementum particularly in more apical areas. The smear layer formed during root planing inhibits cell migration and attachment leading to impaired marginal periodontal healing. The present study was done to compare the morphological effects of root surface demineralization using citric acid and EDTA as root-conditioning agents.

MATERIALS AND METHODS

Thirty fragments of human dental roots previously exposed to periodontal disease were scaled and randomly divided into the following groups of treatment: Group I: Hand instrumentation and conditioning with normal saline for 5 minutes as control; group II: Hand instrumentation and conditioning with citric acid (pH 1) for 5 minutes and group III: Hand instrumentation and conditioning with EDTA (pH-7.4) for 5 minutes. Scanning electron microscopy was used to check for the presence of residual smear layer and for measuring the number and area of exposed dentin tubules.

RESULTS

The mean efficacy of smear layer removal was compared between groups I and II, groups I and III and groups II and III, it was found to be statistically significant at 5%. When the mean diameter of the dentinal tubules and mean total surface area occupied by the dentinal tubule orifices was compared between groups II and III it was found to be statistically significant at 1% level of significance.

CONCLUSION

Citric acid causes greater degree of morphological alterations than EDTA and is considered to be a better root-conditioning agent. However, the use of EDTA cannot be ruled out.

CLINICAL SIGNIFICANCE

This study supports the hypothesis that demineralizing agents can be used as an adjunct to the periodontal treatment aiming at restoring the biocompatibility of roots and helps in choosing an appropriate agent for root conditioning.

Comparison of fibrin clot adhesion to dentine conditioned with citric acid, tetracycline, and ethylene diamine tetra acetic acid: An in vitro scanning electron microscopic study

AIM

The purpose of this study was to evaluate and compare the root surface changes subsequent to the application of citric acid, tetracycline, Ethylenediaminetetraacetic acid (EDTA), and the combination of citric acid and tetracycline, and its influence on the adhesion of a fibrin clot with and without mild disruptive forces.

MATERIALS AND METHODS

A total of 100 periodontally diseased root specimens were grouped into Saline (control Group I), 24% EDTA gel (Group-II), Citric acid (Group-III), Tetracycline (Group IV), and Citric acid + tetracycline (Group V) treatment groups containing 20 in each. After root conditioning, fresh human blood was applied to each root specimen and was allowed to clot. Ten specimens in each group were rinsed in phosphate-buffered saline and designated as 'Non-agitated'. The remaining ten specimens from each group were rinsed in phosphate-buffered saline on a rotary shaker and designated as 'Agitated'. The roots were processed for scanning electron microscopy (SEM) to assess and compare the clot adhesion on them. The scores were compared through standard statistical packages.

RESULTS

The highest mean blood clot adhesion score was observed in roots treated with a combination of citric acid and tetracycline, whereas, the least score was observed in roots treated with saline.

CONCLUSION

The root specimens treated with the combination of citric acid and tetracycline as well as citric acid alone, best supported the fibrin clot. Tetracycline alone appeared to be less effective in supporting the clot. EDTA gel of 24% was least effective to promote the adhesion of a fibrin clot.