EDTA Gel Research Articles

The effect of laterally positioned flap-revised technique and 24% ethylenediaminetetraacetic acid root conditioning on root coverage: A case report.

Complete root coverage is considered the true goal of treatment of gingival recession defects because only complete coverage assures recovery from the hypersensitivity and esthetic defects associated with recession areas. Previous studies have shown that the laterally positioned flap (LPF) technique or root surface biomodification yields a higher percentage of complete root coverage upon gingival recession treatment. This article highlights the use of the laterally positioned pedicle flap-revised technique (LPFRT) as a modification of the LPF technique, along with 24% EDTA gel as a root surface biomodification agent, in the management of localized gingival recession defects. Clinical examination revealed a Miller class II recession defect on the buccal aspect of the lower right central incisor, as well as the presence of aberrant frenum pull adjacent to the recession defect. The LPFRT, together with 24% EDTA gel, was speculated to cover the gingival recession defect. The frenectomy, along with periosteal fenestration, was planned simultaneously with LPFRT. After 6months of therapy, the clinical condition was stable with complete root coverage and satisfactory healing of the gingival tissues at both the donor and recipient sites with no signs of inflammation.

Effect of Bioconditioning on Surface Characteristics of Periodontally-affected Roots of Diabetic Patients

ABSTRACT Objective Advanced glycosylated end products (AGEs) in type II diabetic patients are usually precipitated on the periodontallyaffected root surfaces. The presence of periodontopathic microbes, at the same time, may also add a negative impact on the prognosis of the regenerative periodontal surgery. This in vitro study aimed to evaluate the effect of chemical conditioning on surface characteristics of periodontally-affected roots of diabetic patients. Methods Three groups (n = 25) of freshly-extracted teeth were collected from the outpatient clinics, College of Dentistry, King Khalid University. In group 1, teeth were collected from healthy individuals for orthodontic purpose. Teeth of group 2 were collected from healthy patients with chronic periodontitis, while those of group 3 were collected from diabetic patients with chronic periodontitis. Roots of the collected teeth were examined using the scanning electron microscope (SEM) before and after mechanical surface planning and chemical treatment using normal saline, EDTA gel, Tetracycline HCL (TC) or citric acid (CA) each for 4 minutes (n = 5 from each group). Results Interpretation of SEM images revealed undesirable etching effect of the chemicals used on the surfaces of healthy roots. Although EDTA showed an effective cleanse of the smear debris, it seemed to have no power on surface cuticles existed on roots of diabetic individuals. Tetracycline HCl provided acceptable conditioning of periodontally-affected root surfaces. Citric acid showed a powerful removal of both smear debris and cuticle layers off the periodontally-affected roots of diabetic individuals. Conclusion Topical application of EDTA, TC or CA shows sensible effect on the periodontally affected root surfaces. However, each of these chemicals exhibits different conditioning power. Citric acid is a promising agent to biomodify the periodontally-affected root surfaces of diabetic patients. Clinical relevance Citric acid is an acceptable biomodifier for the periodontally-affected root surfaces. This approach may improve the prognosis of periodontal therapies especially in type II diabetic patients. How to cite this article Abdelaziz KM, Eid HA, Eid RA. Effect of Bioconditioning on Surface Characteristics of Periodontally- affected Roots of Diabetic Patients. World J Dent 2014;5(2):81-86.

Mixed Nano/Micro‐Sized Calcium Phosphate Composite and EDTA Root Surface Etching Improve Availability of Graft Material in Intrabony Defects: An In Vivo Scanning Electron Microscopy Evaluation

The use of nanoparticles of graft materials may lead to breakthrough applications for periodontal regeneration. However, due to their small particle size, nanoparticles may be eliminated from periodontal defects by phagocytosis. In an attempt to improve nanoparticle retention in periodontal defects, the present in vivo study uses scanning electron microscopy (SEM) to evaluate the potential of micrograft particles of β-tricalcium phosphate (β-TCP) to enhance the binding and retention of nanoparticles of hydroxyapatite (nHA) on EDTA-treated and non-treated root surfaces in periodontal defects after 14 days of healing. Sixty patients having at least two hopeless periodontally affected teeth designated for extraction were randomly divided into four treatment groups (15 patients per group). Patients in group 1 had selected periodontal intrabony defects grafted with nHA of particle size 10 to 100 nm. Patients in group 2 were treated in a similar manner but had the affected roots etched for 2 minutes with a neutral 24% EDTA gel before grafting of the associated vertical defects with nHA. Patients in group 3 had the selected intrabony defects grafted with a composite graft consisting of equal volumes of nHA and β-TCP (particle size 63 to 150 nm). Patients in group 4 were treated as in group 3 but the affected roots were etched with neutral 24% EDTA as in group 2. For each of the four groups, one tooth was extracted immediately, and the second tooth was extracted after 14 days of healing for SEM evaluation. Fourteen days after surgery, all group 1 samples were devoid of any nanoparticles adherent to the root surfaces. Group 2 showed root surface areas 44.7% covered by a single layer of clot-blended grafted particles 14 days following graft application. After 14 days, group 3 samples appeared to retain fibrin strands devoid of grafted particles. Immediately extracted root samples of group 4 had adherent graft particles that covered a considerable area of the root surfaces (88.6%). Grafted particles appeared to cover all samples in a multilayered pattern. After 14 days, the group 4 extracted samples showed multilayered fibrin-covered nano/micro-sized graft particles adherent to the root surfaces (78.5%). The use of a composite graft consisting of nHA and microsized β-TCP after root surface treatment with 24% EDTA may be a suitable method to improve nHA retention in periodontal defects with subsequent graft bioreactivity.

Mn–Co spinel protective–conductive coating on AL453 ferritic stainless steel for IT-SOFC interconnect applications

This paper presents research on the synthesis and properties of the Mn1.5Co1.5O4 (MC) spinel powder, as well as its application for the preparation of a MC thick film on the AL453 steel to be used for metallic interconnect material in IT-SOFCs. In order to prepare the MC micropowder with excellent homogeneity of the chemical and phase compositions, EDTA gel processes were utilized. In order to improve the contact electrical resistance between an AL453 steel interconnect and the La0.8Sr0.2FeO3 (LSF) cathode and protect the cathode from Cr poisoning, the surface of the AL453 steel was coated with a protective manganese cobaltite spinel matrix using screen printing in combination with an appropriate heat treatment. The oxidation of the AL453/MC composite layer carried out in the air–H2O gas mixture at 1,073 K for 55 h showed that the spinel coating may serve as an effective barrier against outward Cr diffusion from the AL453 steel and, therefore, significantly inhibit the formation of volatile Cr vapors from the chromia scale. The contact ASR study of the interconnect–cathode interface in the AL453/MC/LSCM/LSF/LSCM/MC/AL453 system carried out in the range of 723−1,073 K in air showed a very large drop in ASR compared to the resistance of the AL453/LSCM/LSF/LSCM/AL453 system without the spinel coating.

Chemical debridement of contaminated titanium surfaces: An in vitro study

Objective. To compare the efficacy of different chemical solutions when used for chemical debridement of biofilm contaminated titanium surfaces in an in-vitro experimental study. Materials and methods. Commercially pure titanium discs with a diameter of 6.2 mm and height of 2 mm, mirror-polished with a measured surface amplitude value SA = 0.037 μm ± 0.009 were used as test-surfaces. A biofilm was simulated with multi-layers of Staphylococcus epidermidis ATCC359844 covering the entire titanium surface. The chemical agents tested were: 3% H2O2, 0.2% Chlorhexidine, 24% EDTA-gel, 3% H2O2 mixed with 1.6 g/L TiO2 and sterile saline solution. The decontamination effect was evaluated by optical density analysis using spectrophotometry and with scanning electron microscopy (SEM) images of the remaining biofilm. Results. The suspensions of 3% H2O2 and 1.6 g/L TiO2 or 3% H2O2 alone were the most effective in removing S. epidermidis biofilms (p < 0.05), whereas 0.2% chlorhexidine or 24% EDTA gel had no significant effects. SEM images of the remaining biofilms supported the quantitative results indicating the higher efficacy of 3% H2O2 and 1.6 g/L TiO2 or 3% H2O2 alone. It also revealed that EDTA, despite a non-significant effect on reducing the amount of established biofilms, was able to alter the biofilm architecture, as demonstrated by increased interspaced regions. Conclusions. In this in vitro study the decontamination potential of a suspension of 3% H2O2 and 1.6 g/L TiO2 or 3% H2O2 alone were encouraging. Whether such procedures would have a similar effect in vivo remains to be determined.

Synthesis and characterization of the manganese cobaltite spinel prepared using two “soft chemical” methods

Using the coprecipitation method and EDTA gel processes, manganese cobaltite (Mn1.5Co1.5O4) powders were successfully synthesized. The thermal decomposition behavior of the gel precursors, phase formation and morphology of the Mn1.5Co1.5O4 powders were characterized by means of DTA/TGA and MS analyses, X-ray diffraction (XRD), and scanning electron microscopy (SEM), respectively. Well-crystallized dual-phase manganese cobaltite spinel, containing both the cubic and tetragonal phases, was obtained at room temperature for both types of powders calcinated at 800 °C for 10 h in static air, without formation of any intermediate phase. SEM investigations show that the Mn1.5Co1.5O4 powders prepared using two “soft chemical” methods were agglomerates composed of approximately micron-sized particles. The structure and morphology of the bulk samples, as well as their electrical conductivity, were investigated using XRD, SEM, and EIS, respectively. Mn1.5Co1.5O4 spinels with different microstructure exhibited excellent electrical conductivity and structural stability. Major emphasis was placed on structural transformations of the spinel solid solutions with temperature and their effect on the electrical properties of these solutions.

EDTA Improves Stability of Whole Blood C-Peptide and Insulin to Over 24 Hours at Room Temperature

IntroductionC-peptide and insulin measurements in blood provide useful information regarding endogenous insulin secretion. Conflicting evidence on sample stability and handling procedures continue to limit the widespread clinical use of these tests. We assessed the factors that altered the stability of insulin and C-peptide in blood.MethodsWe investigated the impact of preservative type, time to centrifugation, storage conditions and duration of storage on the stability of C-peptide and insulin on three different analytical platforms.ResultsC-peptide was stable for at least 24 hours at room temperature in both centrifuged and whole blood collected in K+-EDTA and serum gel tubes, with the exception of whole blood serum gel, which decreased to 78% of baseline at 24 hours, (p = 0.008). Insulin was stable at room temperature for 24 hours in both centrifuged and whole blood collected in K+-EDTA tubes. In contrast insulin levels decreased in serum gel tubes both centrifuged and whole blood (66% of baseline, p = 0.01 and 76% of baseline p = 0.01, by 24 hours respectively). C-peptide and insulin remained stable after 6 freeze-thaw cycles.ConclusionsThe stability of C-peptide and insulin in whole blood K+-EDTA tubes negates the need to conform to strict sample handling procedures for these assays, greatly increasing their clinical utility.

Effect of PDGF-BB combined with EDTA gel on adhesion and proliferation to the root surface

Periodontal regeneration using EDTA or PDGF showed promising results, but the effect of combined application was still unclear. This study aimed to verify the effect of EDTA and/or PDGF application on root adhesion and proliferation of PDL fibroblast cells. Eighty specimens were prepared from forty periodontitis teeth and made five groups: (1) diseased (untreated), (2) SRP (scaling root planing), (3) EDTA (24%), (4) PDGF (25 ng/ml) and (5) Combined application of EDTA and PDGF. Periodontal ligament cells were cultured on the above conditioned dentin plate, and SEM examination was preformed and cells were counted within a representative standard area for both cell morphology and density. All groups including untreated showed significantly increase of adhered cells from baseline to 7 days. Among them, rate of increase was much higher in EDTA, PDGF, and combined groups. ANOVA test indicated that the number of cells in PDGF and combined groups was significantly higher than diseased group at 1 day. On day 7, PDGF and combined groups showed significantly higher number of adhesion cells than that found in the diseased, SRP and EDTA groups. Thus, root conditioning with EDTA enhanced cell adhesion more than SRP alone. There was no significant difference of cell number between PDGF and combined group. Combined application of EDTA and PDGF increased significantly PDL cell adhesion than EDTA alone. PDGF alone, however, also showed comparable effect to combined application at all periods. Thus, synergistic effect between PDGF and EDTA was not observed.

Enhanced β‐Tricalcium Phosphate Blended Clot Adhesion to EDTA Biomodulated Periodontally Affected Root Surfaces: In Vivo Scanning Electron Microscopy Evaluation

The objective of this study is to evaluate β-tricalcium phosphate (β-TCP) blended clot adhesion to EDTA-conditioned root surfaces. Sixty patients with chronic periodontitis and two teeth designated for extraction were enrolled in this study. Patients were divided into six groups (G1 to G6; 10 patients in each). In G1, intrabony defects were grafted with β-TCP with a particle size ranging from 150 to 500 μm. In G2, intrabony defects were grafted with β-TCP with a particle size ranging from 63 to 150 μm. Roots in G3 were etched for 2 minutes with a neutral EDTA, followed by defect overfill of the β-TCP used for G1. Defects of G4 were treated by the same method as in G3, except the EDTA gel application was 4 minutes. Roots in G5 and G6 were etched for 2 and 4 minutes, respectively, followed by the defect fill with β-TCP used for G2. For each patient, one tooth was extracted immediately after surgery and the other tooth was extracted at 14 days for scanning electron microscopy evaluation. Fourteen days after surgery, the G1 and G2 samples revealed undetected graft particles. The G3 samples showed areas of adherent β-TCP particles covering about 42.5%. The G4 samples showed 53.7% graft material coverage. The G5 and G6 samples had adherent grafted particles that covered 77.9% and 82.7%, respectively. Root conditioning with EDTA gel improves β-TCP blended clot adhesion to periodontally involved root surfaces.

Effect of intracanal irrigants on the bond strength of epoxy resin‐based and methacrylate resin‐based sealers to root canal walls

To assess the bond strength of Epiphany and AH Plus sealers to root canal walls using a push-out test after use of several endodontic irrigants. Roots of 100 maxillary canines were sectioned horizontally 5 mm below the cemento-enamel junction to provide 4-mm-thick dentine disks that were embedded in acrylic resin and had their root canals prepared with a tapered bur (larger diameter=2.70 mm; smaller diameter=2.30 mm; length = 4 mm). The specimens were randomly assigned to five groups (n=20) according to the dentine surface treatment: I - 1% NaOCl (30 min); II - 1% NaOCl (30 min) + 17% EDTA (5 min); III - 17% EDTA (30 min); IV - 24% EDTA gel (30 min); V - 2% chlorhexidine gluconate (CHX) gel (30 min). In each group, two specimens were prepared for scanning electron microscopy to examine the surface of root canal dentine after use of each irrigant. The other 18 specimens were filled with AH plus (n = 9) or Epiphany (n=9) and subjected to a push-out test in an Instron machine. Data (in MPa) were subjected to statistical analysis by two-way anova and post-hoc Tukey-Kramer test (P < 0.05). AH Plus had a significantly higher bond strength (8.74 ± 2.75) than Epiphany (6.74 ± 3.97) (P < 0.05). One per cent NaOCl/17% EDTA was associated with significantly higher bond strength values (10.88 ± 3.05) than the other irrigants (P < 0.05). Seventeen per cent EDTA (8.75 ± 1.75), 24% EDTA gel (7.48 ± 3.48) and 2% CHX gel (7.89 ± 3.41) had intermediate values that were not significantly different from each other (P > 0.05). One per cent NaOCl was associated with the lowest mean values (3.70 ± 0.86) (P < 0.05). The interaction between surface treatment and sealer revealed significantly higher bond strength for 24% EDTA gel with AH Plus, 2% CHX gel with AH Plus and 1%NaOCl/17%EDTA with Epiphany (P < 0.05). Except for 1% NaOCl, the removal of smear layer with the other irrigants increased the bond strength of AH Plus to intracanal dentine. The use of 1% NaOCl for 30 min with 17% EDTA as final irrigant for 5 min increased the bond strength of Epiphany.

Initial fibroblast attachment to Erbium:YAG laser‐irradiated dentine

To evaluate the effects of Erbium (Er):YAG laser irradiation on the morphology of resected dentine surfaces, and to investigate fibroblast attachment to laser-irradiated dentine surfaces. Dentine blocks obtained from single-rooted human teeth were divided into the following groups after sterilization in an autoclave: (i) Laser group treated with Er:YAG laser irradiation (30 mJ per pulse, 10 pps, 60 s); (ii) L-MTAD group treated with laser irradiation as in (i) plus a mixture of doxycycline, tetracycline isomer and citric acid; (iii) RC-Prep group treated with EDTA gel or cream (RC-Prep) and (iv) Control group left untreated. After each treatment, the dentine blocks were incubated with NIH/3T3 fibroblasts cultured to subconfluency in Dulbecco's modified Eagle's medium supplemented with 10% foetal bovine serum and antibiotics. The number of attached cells amongst the groups was analysed statistically at the 5% significance level. The dentine surface morphologies and cell attachments were evaluated by counting assays, histological observations and scanning electron microscopy (SEM). The number of attached cells was significantly higher (P < 0.05) in the Laser group than in the RC-Prep and Control groups at 16 h. Dendritic cell extension of the fibroblasts was only observed in the Laser group at 8 h by SEM. In the histological analyses, significantly more attached cells were found on the dentine surfaces treated with laser irradiation. Er:YAG laser irradiation induced morphological alterations in dentine surfaces, which may improve the attachment of fibroblasts to dentine.

Surgical therapy of peri-implantitis lesions by means of a bovine-derived xenograft: comparative results of a prospective study on two different implant surfaces

The aim of this prospective study was to evaluate a regenerative surgical treatment modality for peri-implantitis lesions on two different implant surfaces. Twenty-six patients with one crater-like defect, around either TPS (Control) or SLA (Test) dental implants, with a probing depth (PD) ≥6 mm and no implant mobility, were included. The implant surface was mechanically debrided and treated using a 24% EDTA gel and a 1% chlorhexidine gel. The bone defect was filled with a bovine-derived xenograft (BDX) and the flap was sutured around the non-submerged implant. One-year follow-up demonstrated clinical and radiographic improvements. PDs were significantly reduced by 2.1±1.2 mm in the Control implants and by 3.4±1.7 mm in the Test implants. Complete defect fill was never found around Controls, while it occurred in three out of 12 Test implants. Bleeding on probing decreased from 91.1±12.4% (Control) and 75.0±30.2% (Test) to 57.1±38.5% (p=0.004) and 14.6±16.7% (p=0.003), respectively. Several deep pockets (≥6 mm) were still present after surgical therapy around Controls. Surface characteristics may have an impact on the clinical outcome following surgical debridement, disinfection of the contaminated surfaces and grafting with BDX. Complete fill of the bony defect seems not to be a predictable result.

Chlorhexidine Controlled‐Release Profile After EDTA Root Surface Etching: An In Vivo Study

The main objective of the present study was to quantify chlorhexidine (CHX) release after the use of CHX-EDTA root surface treatment as a local-delivery antimicrobial vehicle. Twenty non-smoking patients clinically diagnosed as having moderate-to-severe chronic periodontitis were selected to participate in this study. After cause-related therapy, one site in every patient received defect overfill with CHX gel 2% (20 sites). In addition, twenty contralateral sites received defect fill of CHX gel after 3 minutes of 24% EDTA gel root surface etching (20 sites). Gingival crevicular fluid samples were collected at 1, 3, 7, and 14 days post-therapy. The CHX-EDTA group showed statistically significantly higher levels of CHX than those of the control group at 1, 3, and 7 days. At 14 days, the CHX-EDTA group showed 0.8 mg/mL values. The use of CHX-EDTA root surface treatment as a local-delivery antimicrobial improves CHX substantivity.

Mechanical and acid root treatment on periodontally affected human teeth: a scanning electronic microscopy

Abstract Aim: To evaluate the root topography of human teeth affected by periodontitis, after different root surface treatments. Methods: Forty-two periodontally affected single-rooted human teeth were selected and randomly divided into 7 groups (n=6): Cont- control group, which received no treatment; Sca- root surface scaling and root planning with curettes; ScaPh- Sca followed by 37% phosphoric acid gel etching for 15 s; ScaEdta- Sca followed by 24% EDTA gel pH 7 for 1 min; ScaCi- Sca followed by 30% citric acid pH 1.6 for 5 min; ScaTe- Sca followed by - mixture obtained by 500 mg tetracycline capsule dissolved in saline solution for 3 min; ScaTeg- Sca followed by 0.2 g/mL tetracycline gel pH 1.8 for 1 min. The specimens were analyzed by scanning electronic microscopy to verify the presence of calculus, demineralization level and residues of the product. Results: Calculus deposits were found in all control specimens. ScaEdta, ScaCi and ScaTeg removed completely calculus deposits and resulted in adequate demineralization without smear layer and smear plug on root surface. ScaTe produced great tetracycline residues with several demineralization areas on root dentin surface. Conclusions: ScaEdta, ScaCi and ScaTeg produced clean root surfaces associated with regular dentin demineralization.

Wound healing following regenerative procedures in furcation degree III defects: histomorphometric outcomes

Degree III furcation involvements were surgically created at four first molars in each of three monkeys. Following 6 weeks of healing, full-thickness flaps were elevated. Following 24% EDTA gel conditioning, the defects were treated with one of the following: (1) enamel matrix proteins (EMD), (2) guided tissue regeneration (GTR) or (3) a combination EMD and GTR. The control defects did not receive any treatment. After 5 months of healing, the animals were sacrificed. Three 8 μm thick histological central sections, 100 μm apart, were used for histomorphometric analysis in six zones of each tooth either within the furcation area or on the pristine external surface of the root. In all specimens, new cementum with inserting collagen fibres was formed. Following GTR or GTR + EMD, cementum was formed up to and including the furcation fornix indicating complete regeneration on the defect periphery. Periodontal ligament fibres were less in all four modalities compared to pristine tissues. In the teeth treated with GTR and GTR + EMD a higher volume of bone and periodontal ligament tissues was observed compared to EMD. After 5 months of healing, regenerated tissues presented quantitative differences from the pristine tissues. In the two modalities where GTR alone or combined with EMD was used, the regenerated tissues differed in quantity from the EMD-treated sites.

An SEM evalution of the type of smear layer produced by newer rotary instruments and effectiveness of different combinations of irrigants

The present in vitro study evaluated the smear layer formed with newer Protaper series of rotary instruments in comparison with the conventional hand instruments and the Profile series of rotary instruments. The results of the study showed that the Protaper series of rotary instruments caused the maximum amount of smear layer, followed by the Profile series of rotary instruments. The hand instruments caused the least amount of smear layer. The second phase of the study evaluated the efficacy of smear layer removal using different combinations of irrigants. The results of the study showed that 3% sodium hypochlorite in combination with 15% EDTA liquid removed the maximum amount of smear layer, followed by the combination of 3% sodium hypochlorite and GLYDE (EDTA gel). The smear layer removal was the least, when 3% sodium hypochlorite was used alone.

Physiological and Biochemical Defects in Carboxyl-terminal Mutants of Mitochondrial DNA Helicase

Mitochondrial DNA helicase, also called Twinkle, is essential for mtDNA maintenance. Its helicase domain shares high homology with helicases from superfamily 4. Structural analyses of helicases from this family indicate that carboxyl-terminal residues contribute to NTP hydrolysis required for translocation and DNA unwinding, yet genetic and biochemical information is very limited. Here, we evaluate the effects of overexpression in Drosophila cell culture of variants carrying a series of deletion and alanine substitution mutations in the carboxyl terminus and identify critical residues between amino acids 572 and 596 of the 613 amino acid polypeptide that are essential for mitochondrial DNA helicase function in vivo. Likewise, amino acid substitution mutants K574A, R576A, Y577A, F588A, and F595A show dose-dependent dominant-negative phenotypes. Arg-576 and Phe-588 are analogous to the arginine finger and base stack of other helicases, including the bacteriophage T7 gene 4 protein and bacterial DnaB helicase, respectively. We show here that representative human recombinant proteins that are analogous to the alanine substitution mutants exhibit defects in nucleotide hydrolysis. Our findings may be applicable to understand the role of the carboxyl-terminal region in superfamily 4 DNA helicases in general.

The effect of chemical and/or mechanical conditioning on the Er:YAG laser‐treated root cementum: Analysis of surface morphology and periodontal ligament fibroblast attachment

This study compared the surface morphology as well as the biocompatibility of dental root cementum treated with Er:YAG laser irradiation alone and with the laser irradiation followed by chemical and/or mechanical conditioning. Healthy cementum plates were randomly assigned to the following control and treatment groups: (1) untreated control (C), (2) Er:YAG laser irradiation (L), (3) laser plus tetracycline HCl (TC) placement (L+TP), (4) laser plus TC burnishing (L+TB), (5) laser plus EDTA gel placement (L+EP), (6) laser plus EDTA gel burnishing (L+EB), (7) laser plus saline solution burnishing (L+SB), and (8) laser plus minocycline-HCl paste placement (L+MP). Specimens were subjected to scanning electron microscopy (SEM), histological observation and attachment assay using periodontal ligament (PDL) fibroblasts. The laser irradiation produced a thin affected layer (5.7 microm thickness) with a superficial microstructure on the cementum surface. The characteristic microstructures of the lased surface were fragile and could be removed by chemical and/or mechanical conditioning treatments. The L+TB group exhibited marked exposure of collagen fibers after removal of the microstructures on the lased surface. The L+EP group presented a peculiar, smooth surface without exposure of collagen fibers and a uniform arrangement of spherical microparticles on the ultra-high magnification of SEM. In cell attachment assay, the L+TB group exhibited the greatest number of attached cells among all the groups, followed by the L+EP, L+SB and control group. The laser alone group exhibited the lowest number of cells. The characteristic microstructure of the root cementum surface after Er:YAG laser irradiation has a tendency to hinder the early attachment of PDL cells. However, chemical and/or mechanical root conditioning treatment may improve and increase the biocompatibility of the Er:YAG laser-treated root cementum by removing the microstructures of the surface and/or further exposing the collagen fibers.

Safe and legal shipment of tissue samples: does it affect DNA quality?

Safe and legal shipment of tissue samples: does it affect DNA quality?

Effects of EDTA Gel Preconditioning of Periodontally Affected Human Root Surfaces on Chlorhexidine Substantivity – An SEM Study

Infection control is an important requirement during the early stages of periodontal healing. This study was performed to assess the preconditioning effect of EDTA gel on chlorhexidine (CHX) substantivity to periodontally involved root surfaces. Eighty patients with severe chronic periodontitis were enrolled in this study. Following cause-related therapy, patients were divided randomly into four groups. Each group consisted of 20 subjects with one tooth that was diagnosed as hopeless and designated for extraction. In group 1 (G1), selected periodontal pockets were filled with a placebo gel in a silica base for 2 minutes. Exposed roots in group 2 (G2) were etched for 2 minutes with a neutral EDTA conditioning agent, followed by pocket fill with the placebo gel. Pockets in group 3 (G3) were filled with 0.12% CHX digluconate gel in a silica base. Exposed roots in group 4 (G4) were etched for 2 minutes with a neutral EDTA conditioning agent, followed by pocket fill with the CHX gel. Four teeth from each group were extracted immediately and at 3, 12, 24, and 48 hours for SEM evaluation. G1 and G2 specimens showed no evidence of silica adherent to any of the examined root surfaces. At 3 hours following CHX gel application, G3 specimens showed marked reduction in CHX-coated silica. At 24 and 48 hours following EDTA and CHX gel application, G4 specimens demonstrated adherent CHX-coated silica particles despite the reclogging of the tubule orifices. EDTA and CHX gel root conditioning is a valuable regimen that improves CHX substantivity to periodontally involved root surfaces.