Periodontitis-affected Teeth Research Articles

A cleaved adhesin DNA vaccine targeting dendritic cell against Porphyromonas gingivalis-induced periodontal disease.

Arg-gingipain A (RgpA) is the primary virulence factor of Porphyromonas gingivalis and contains hemagglutinin adhesin (HA), which helps bacteria adhere to cells and proteins. Hemagglutinin's functional domains include cleaved adhesin (CA), which acts as a hemagglutination and hemoglobin-binding actor. Here, we confirmed that the HA and CA genes are immunogenic, and using adjuvant chemokine to target dendritic cells (DCs) enhanced protective autoimmunity against P. gingivalis-induced periodontal disease. C57 mice were immunized prophylactically with pVAX1-CA, pVAX1-HA, pVAX1, and phosphate-buffered saline (PBS) through intramuscular injection every 2 weeks for a total of three administrations before P. gingivalis-induced periodontitis. The DCs were analyzed using flow cytometry and ribonucleic acid sequencing (RNA-seq) transcriptomic assays following transfection with CA lentivirus. The efficacy of the co-delivered molecular adjuvant CA DNA vaccine was evaluated in vivo using flow cytometry, immunofluorescence techniques, and micro-computed tomography. After the immunization, both the pVAX1-CA and pVAX1-HA groups exhibited significantly elevated P. gingivalis-specific IgG and IgG1, as well as a reduction in bone loss around periodontitis-affected teeth, compared to the pVAX1 and PBS groups (p<0.05). The expression of CA promoted the secretion of HLA, CD86, CD83, and DC-specific intercellular adhesion molecule-3-grabbing non-integrin (DC-SIGN) in DCs. Furthermore, the RNA-seq analysis revealed a significant increase in the chemokine (C-C motif) ligand 19 (p<0.05). A notable elevation in the quantities of DCs co-labeled with CD11c and major histocompatibility complex class II, along with an increase in interferon-gamma (IFN-γ) cells, was observed in the inguinal lymph nodes of mice subjected to CCL19-CA immunization. This outcome effectively illustrated the preservation of peri-implant bone mass in rats afflicted with P. gingivalis-induced peri-implantitis (p<0.05). The co-administration of a CCL19-conjugated CA DNA vaccine holds promise as an innovative and targeted immunization strategy against P. gingivalis-induced periodontitis and peri-implantitis.

RgpA-Engineered/Functionalized DNA Vaccine as a Novel Prophylactic Vaccination to Prevent Porphyromonas gingivalis-Induced Periodontitis: An in Vivo Study.

Arg-gingipain A (rgpA) and Arg-gingipain B (rgpB) are crucial virulence factors associated with Porphyromonas gingivalis (P. gingivalis) and have been recognized as promising targets for antibacterial vaccines. Although vaccines containing rgpA have shown efficacy, the incorporation of rgpB, which lacks the haemagglutinin adhesin (HA) domain, diminishes the vaccine's effectiveness. This study aims to assess the immunogenicity of the functional HA domain of rgpA in mouse periodontitis models. A total of 24 mice were randomly divided into four groups, each receiving different immune injections: group A received phosphate-buffered saline (PBS) as an empty control; group B received pVAX1 as a negative control (NC); group C received pVAX1-HA; and group D received pVAX1-rgpA. The mice were subjected to intramuscular injections every two weeks for a total of three administrations. Prior to each immunization, blood samples were collected for antibody detection under isoflurane anesthesia. Following the final immunization, periodontitis was induced two weeks later by using sutures soaked in a P. gingivalis solution. The mice were euthanized after an additional two-week period. To assess the safety of the procedure, major organs were examined through hematoxylin-eosin (HE) staining. Subsequently, the levels of IgG, IgG1, and IgG2a in the serum were quantified via enzyme-linked immunosorbent assay (ELISA). Additionally, the expression of inflammatory factors in the gingiva, including interleukin-6 (IL-6), interleukin-1β (IL-1β), and tumor necrosis factor alpha (TNF-α), was determined using quantitative real-time reverse transcript PCR (qRT-PCR). The extent of bone loss in periodontal tissues was evaluated using micro-computed tomography (micro-CT) and HE staining. HE staining of the organs confirmed the absence of vaccine-induced toxicity in vivo. After the second immunization, both the rgpA and HA groups displayed significantly higher specific IgG titers in comparison to the NC and PBS groups (p < 0.05). Furthermore, the rgpA and HA groups exhibited a noteworthy predominance of IgG1 antibodies after three immunization doses, while there was a noticeable reduction in IgG2a levels observed following ligation with P. gingivalis sutures, as opposed to the NC and PBS groups (p < 0.05). Additionally, both the HA and rgpA groups showed a significant decrease in the expression of inflammatory factors such as IL-6, IL-1β, and TNF-α, as well as a reduction in bone loss around periodontitis-affected teeth, when compared to the NC and PBS groups (p < 0.05). The results of this study demonstrate that the rgpA-engineered/functionalized HA gene vaccine is capable of eliciting a potent prophylactic immune response against P. gingivalis-induced periodontitis, effectively serving as an immunogenic and protective agent in vivo.

Herpesvirus-Bacteria pathogenic interaction in juvenile (aggressive) periodontitis. A novel etiologic concept of the disease.

Localized juvenile (aggressive) periodontitis starts at puberty in otherwise healthy individuals and involves the proximal surfaces of permanent incisors and first molars. The disease destroys a sizeable amount of periodontal bone within a few months despite minimal dental plaque and gingival tissue inflammation. Cytomegalovirus and Epstein-Barr virus, as well as the two main periodontopathic bacteria Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis, are linked to juvenile periodontitis. Juvenile periodontitis-affected teeth show cementum hypoplasia. We hypothesize that an active herpesvirus infection, at the time of root formation, hampers cementum formation and, at puberty, herpesvirus reactivation triggers an upgrowth of bacterial pathogens which produce rapid periodontal destruction on teeth with a defective periodontium. A pathogenic interaction between active herpesviruses and bacterial pathogens can potentially explain the etiology and incisor-first molar destructive pattern of juvenile periodontitis. Effective treatment of juvenile periodontitis may target the herpesvirus-bacteria co-infection.

Possibility of Raman spectroscopy method use for evaluation of periodontitis-affected tooth enamel before and after open curettage

The results of the research of enamel of periodontitis-affected teeth before and after open curettage are presented in the work. The Raman spectroscopy method was used as an evaluation method of curettage influence on tooth enamel. Chemometric analysis of the Raman spectra of tooth enamel before and after curettage was made. Spectral changes of tooth enamel were detected. It was found that after the procedure of open curettage spectral changes occur in tooth enamel related to the changes in mineral composition and organic matrix forming.

Preliminary Evaluation of Proliferation, Wound Healing Properties, Osteogenic and Chondrogenic Potential of Dental Pulp Stem Cells Obtained from Healthy and Periodontitis Affected Teeth

Background: Dental pulp tissue within the central cavity of the tooth is composed of dental pulp stem cells (DPSC). These mesenchymal stem cells have good proliferative as well as differentiation potential. DPSC has been isolated even from teeth with inflamed pulps and is found to retain their proliferative and differentiation potential. Little research is available about the viability and differentiation potential of DPSC obtained from teeth with periodontitis. In the present study, the aim was to compare the morphological features, stem cell marker (MSC) expression, proliferation rate, migratory and wound healing properties, osteogenic and chondrogenic differentiation potential of DPSCs obtained from periodontally healthy teeth (hDPSCs) and periodontitis affected teeth (pDPSCs). Methods: Dental pulp tissue was obtained from periodontally healthy volunteers (n = 3) and patients with periodontitis undergoing extraction of mobile teeth (n = 3). DPSC were isolated using the explant technique and cultured. All the experiments were performed at early passage (Passage 2), late passage (Passage 6) and after cryopreservation. Morphological features of the hDPSCs and pDPSCs were ascertained using microscopy. The expression of cell surface stem cell markers was assessed by the flow cytometry method. The proliferation and growth rate of the cells were assayed by plotting a growth curve from 0–13 days of culture. The migratory characteristics were assessed by wound scratch assay. Osteogenic and chondrogenic differentiation of the cells was assessed using standard protocols with and without induction. Results: DPSCs were successfully obtained from periodontally healthy teeth (hDPSC) and periodontitis-affected teeth (pDPSCs). The data suggests that there were no morphological differences observed in early passage cells between the two cohorts. Cryopreservation did change the morphology of pDSPCs. There was no significant difference in the positive expression of mesenchymal markers CD73, CD90 and CD105 in early passage cells. However, serial passaging and cryopreservation affected the marker expression in pDPSCs. A faint expression of hematopoietic stem cell markers CD34, CD45 and MHC class II antigen HLA-DR was observed in both the cell types. The expression of HLA-DR is upregulated in pDPSCs compared to hDPSC. A significantly slower growth rate and slower wound healing properties was observed in pDPSCs compared to hDPSC. In late passage and after cryopreservation, the migratory ability of pDPSCs was found to be increased drastically. There was no significant difference in osteogenic potential between the two cell types. However, the chondrogenic potential of pDPSCs was significantly lower compared to hDPSc. Yet, pDPSCs showed enhanced osteogenesis and chondrogenesis at late passage as well as after cryopreservation. Conclusion: The results of this novel study shed light on the isolation of viable DPSC from periodontitis-affected teeth. These cells exhibit a slower growth rate and migratory characteristics compared to their healthy counterparts. There was no difference in osteogenic potential but a reduction in chondrogenic potential was seen in pDPSCs compared to hDPSC. The findings reveal that DPSC from periodontitis-affected teeth presents an easy and viable option for regenerative medicine application. Some additional nutritive factors and protocols may be required to attain better regenerative benefits while using pDPSCs.

MicroRNA-146a downregulates interleukin-13 and inhibits the proliferation of human periodontal ligament stem cells

ObjectiveThis study was carried out to investigate the interaction between microRNA-146a and interleukin-13 (IL-13) in periodontitis. DesignThe expression levels of microRNA-146a and IL-13 in periodontal ligament stem cells (PDLSCs) derived from periodontitis-affected teeth and healthy teeth were detected by real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR). A microRNA-146a mimic was transfected into PDLSCs, and proliferation and IL-13 expression were detected via a cell counting kit-8 (CCK-8) assay and western blot, respectively. ResultsmicroRNA-146a was downregulated and IL-13 was upregulated in PDLSCs derived from periodontitis-affected teeth compared to that in PDLSCs derived from healthy teeth. microRNA-146a and IL-13 were negatively correlated in periodontitis-derived PDLSCs but not in those derived from healthy teeth. The former also exhibited significantly enhanced cell proliferation. Overexpression of microRNA-146a inhibited proliferation of PDLSCs derived from both periodontitis-affected teeth and healthy teeth while downregulating IL-13. ConclusionsmicroRNA-146a may improve periodontitis by downregulating IL-13 and inhibiting the proliferation of human PDLSCs.

LncRNA MAFG-AS1 regulates human periodontal ligament stem cell proliferation and Toll-like receptor 4 expression.

LncRNA MAFG-AS1 is predicted to interact with miR-146a, which can target Toll-like receptor 4 (TLR4), a key player in periodontitis. This study aimed to investigate the roles of MAFG-AS1 in periodontitis. It was observed that MAFG-AS1 was downregulated in the human periodontal ligament stem cells (PDLSCs) derived from periodontitis-affected teeth. Dual-luciferase assay revealed that co-transfection of MAFG-AS1 expression vector and miR-146a mimic showed significantly lower relative luciferase activity comparing to co-transfection of MAFG-AS1 expression vector and negative control (NC) miRNA. However, MAFG-AS1 and miR-146a failed to affect each other. Interestingly, MAFG-AS1 overexpression led to the upregulated TLR4. In addition, MAFG-AS1 overexpression also led to the inhibited proliferation of PDLSCs. Therefore, MAFG-AS1 may regulate the proliferation of PDLSCs and the expression of TLR4 to participate in periodontitis.

Upregulation of IL-10 expression inhibits the proliferation of human periodontal ligament stem cells.

The abnormal increase in proliferation rate of human periodontal ligament stem cells (PDLSCs) is considered to be involved in the pathogenesis of periodontitis, a disease in which the IL-10-mediated anti-inflammatory pathway plays a critical role. This study aimed to investigate the involvement of microRNA-466l in periodontitis and to explore the possible interaction between IL-10 and microRNA-466l. PDLSCs were obtained from periodontitis-affected teeth and healthy control teeth. The expression of microRNA-466l and IL-10 mRNA was measured in PDLSCs using RT-qPCR. The proliferation ability of PDLSCs was analyzed using CCK-8 assays. Overexpression of microRNA-466l in a PDLSC cell line was established using two different types of PDLSCs, and the effect of microRNA-466l overexpression on IL-10 expression and cell proliferation were detected by western blot and CCK-8 assays, respectively. We found that expression levels of microRNA-466l and IL-10 mRNA were significantly lower (P < 0.05) in PDLSCs derived from periodontitis-affected teeth compared to those derived from healthy teeth. However, the cell proliferation ability was significantly higher in the PDLSCs derived from periodontitis-affected teeth. Meanwhile microRNA-466l overexpression decreased cell proliferation rates of both types of PDLSCs and upregulated IL-10 expression. Together, these data suggest that microRNA-466l can upregulate IL-10 and reduce the proliferation rate of PDLSCs.

Downregulation of Linc-RNA activator of myogenesis lncRNA participates in FGF2-mediated proliferation of human periodontal ligament stem cells.

Accelerated proliferation of human periodontal ligament stem cells (PDLSCs) is present in periodontitis. It is known that fibroblast growth factor 2 (FGF2) regulates the proliferation of PDLSCs, while the function of FGF2 in myogenic cell differentiation is mediated by Linc-RNA Activator of Myogenesis (Linc-RAM) lncRNA. Therefore, Linc-RAM lncRNA may also participate in periodontitis. This study included 28 patients with periodontitis (patient group) and 22 patients without periodontitis but received orthodontic treatment (control group) in the stomatological hospital of Sun Yat-Sen university. Gingival biopsies were obtained from participants. RT-qPCR, cell transfection, cell proliferation assay and western blot were carrying out to analyze the samples. We found that FGF2 mRNA was upregulated, while Linc-RAM was downregulated in PDLSCs derived from periodontitis-affected teeth than in healthy teeth. FGF2 mRNA and Linc-RAM were inversely correlated in both types of PDLSCs. FGF2 overexpression led to inhibited Linc-RAM expression in PDLSCs derived from periodontitis-affected teeth and promoted the proliferation of PDLSCs. Linc-RAM overexpression failed to significantly affect FGF2 expression but attenuated the enhancing effects of FGF2 overexpression on the proliferation of PDLSCs. Therefore, downregulation of Linc-RAM lncRNA may participate in FGF-2 mediated- proliferation of human PDLSCs.

MALAT1 overexpression promotes the proliferation of human periodontal ligament stem cells by upregulating fibroblast growth factor 2.

Fibroblast growth factor 2 (FGF2) has been revealed to promote human periodontal ligament stem cell (PDLSC) proliferation. The abnormal proliferation of PDLSCs has also been associated with the pathogenesis of periodontitis. The long non-coding RNA, metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), has been demonstrated to regulate FGF2 secretion. Therefore, MALAT1 may also be associated with periodontitis. The aim of the present study was to investigate the effect of MALAT1 overexpression on the proliferation of PDLSCs. In the current study, PDLSCs derived from healthy and periodontitis-affected teeth were collected. MALAT1 and FGF2 mRNA expression in PDLSCs was detected using reverse transcription-quantitative PCR. PDLSCs overexpressing MALAT1 were subsequently generated. PDLSC proliferation was analyzed using a Cell Counting kit-8 assay. FGF2 protein expression was detected using western blot analysis. The results revealed that MALAT1 and FGF2 mRNA were significantly upregulated in PDLSCs derived from periodontitis-affected teeth when compared with PDLSCs derived from healthy teeth. PDLSCs derived from periodontitis-affected teeth also demonstrated a significantly higher proliferation rate than PDLSCs derived from healthy teeth. MALAT1 and FGF2 mRNA expression were positively correlated in both PDLSC groups. MALAT1 overexpression promoted the proliferation of healthy and periodontitis-affected PDLSC groups and upregulated FGF2 protein expression. The present study concluded that MALAT1 overexpression promoted the proliferation of human PDLSC potentially via upregulating FGF2.

Application of Periodontal Ligament-Derived Multipotent Mesenchymal Stromal Cell Sheets for Periodontal Regeneration.

Periodontitis is a chronic inflammatory disorder that causes destruction of the periodontal attachment apparatus including alveolar bone, the periodontal ligament, and cementum. Dental implants have been routinely installed after extraction of periodontitis-affected teeth; however, recent studies have indicated that many dental implants are affected by peri-implantitis, which progresses rapidly because of the failure of the immune system. Therefore, there is a renewed focus on periodontal regeneration aroundnatural teeth. To regenerate periodontal tissue, many researchers and clinicians have attempted to perform periodontal regenerative therapy using materials such as bioresorbable scaffolds, growth factors, and cells. The concept of guided tissue regeneration, by which endogenous periodontal ligament- and alveolar bone-derived cells are preferentially proliferated by barrier membranes, has proved effective, and various kinds of membranes are now commercially available. Clinical studies have shown the significance of barrier membranes for periodontal regeneration; however, the technique is indicated only for relatively small infrabony defects. Cytokine therapies have also been introduced to promote periodontal regeneration, but the indications are also for small size defects. To overcome this limitation, ex vivo expanded multipotent mesenchymal stromal cells (MSCs) have been studied. In particular, periodontal ligament-derived multipotent mesenchymal stromal cells are thought to be a responsible cell source, based on both translational and clinical studies. In this review, responsible cell sources for periodontal regeneration and their clinical applications are summarized. In addition, recent transplantation strategies and perspectives about the cytotherapeutic use of stem cells for periodontal regeneration are discussed.

Long non-coding RNAs mortal obligate RNA transcript regulates the proliferation of human periodontal ligament stem cells and affects the recurrence of periodontitis

ObjectiveThe aim of this study is to investigate the role of long non-coding RNAs (lncRNA), mortal obligate RNA transcript (MORT), in human periodontal ligament stem cells. DesignPeriodontal ligament tissues were collected from 48 periodontitis patients underwent tooth extraction and 38 people in similar age and gender distributions who experienced orthodontic treatment. After treatment, periodontitis patients were followed up for 2 years. MORT in periodontal ligament stem cells (PDLSCs) was detected by qRT-PCR. Proliferation of PDLSCs was detected by CCK-8 assay. ResultsThe proliferation rate of PDLSCs isolated from periodontitis-affected teeth was significantly higher than PDLSCs from healthy teeth. Overexpression of MORT inhibited the proliferation of both types of periodontal ligament stem cells. After treatment, periodontitis patients were followed up for 2 years and patients with high level of MORT expression showed relatively lower recurrence rate comparing to low expression group. ConclusionMORT is involved in the proliferation of human PDLSCs and affects the recurrence of periodontitis.

MicroRNA-146a downregulates IL-17 and IL-35 and inhibits proliferation of human periodontal ligament stem cells.

Periodontitis is characterized by increased levels of proinflammatory factors, such as interleukin-17 (IL-17) and IL-35. In this study, the expression of microRNA-146a (miRNA-146a), IL-17, and IL-35 in the plasma of patients with periodontitis and healthy controls were detected by quantitative reverse transcription polymerase chain reaction and enzyme-linked immunosorbent assay, respectively. miRNA-146a mimic was transfected into periodontal ligament stem cells (PDLSCs) isolated from periodontitis-affected teeth and healthy teeth. Cell proliferation and expression of IL-17 and IL-35 were detected by cell counting kit-8 assay and Western blot analysis, respectively. It was observed that miRNA-146a was downregulated but IL-17 and IL-35 were upregulated in the plasma of patients withperiodontitis than in healthy controls. miRNA-146a was inversely correlated with IL-17 and IL-35 in patients with periodontitis. miRNA-146a overexpression inhibited proliferation of PDLSCs derived from both periodontitis-affected teeth and healthy teeth. miRNA-146a overexpression led to downregulated IL-17 and IL-35 expression in PDLSCs isolated from periodontitis-affected teeth. We, therefore, conclude that miRNA-146a may improve periodontitis by downregulating IL-17 and IL-35 expression and inhibiting proliferation of human PDLSCs.

Poly(Lactic-co-Glycolic Acid): Applications and Future Prospects for Periodontal Tissue Regeneration.

Periodontal tissue regeneration is the ultimate goal of the treatment for periodontitis-affected teeth. The success of regenerative modalities relies heavily on the utilization of appropriate biomaterials with specific properties. Poly (lactic-co-glycolic acid) (PLGA), a synthetic aliphatic polyester, has been actively investigated for periodontal therapy due to its favorable mechanical properties, tunable degradation rates, and high biocompatibility. Despite the attractive characteristics, certain constraints associated with PLGA, in terms of its hydrophobicity and limited bioactivity, have led to the introduction of modification strategies that aimed to improve the biological performance of the polymer. Here, we summarize the features of the polymer and update views on progress of its applications as barrier membranes, bone grafts, and drug delivery carriers, which indicate that PLGA can be a good candidate material in the field of periodontal regenerative medicine.

A longitudinal assessment of periodontal disease in 52 Miniature Schnauzers.

BackgroundPeriodontal disease (PD) is the most widespread oral disease in dogs and has been associated with serious systemic diseases. The disease is more prevalent in small breeds compared to large breeds and incidence increases with advancing age. In prevalence studies 84% of beagles over the age of 3 and 100% of poodles over the age of 4 were diagnosed with PD. Current knowledge of the rate of progression of PD is limited. The objective of this study was to determine the rate of PD progression in miniature schnauzers, an at risk small breed of dog.Dogs (n = 52, age 1.3-6.9 years) who had received a regular oral care regime prior to this study were assessed for levels of gingivitis and periodontitis around the whole gingival margin in every tooth under general anaesthetic. Assessments were conducted approximately every six weeks for up to 60 weeks following the cessation of the oral care regime.ResultsAll of the 2155 teeth assessed entered the study with some level of gingivitis. 23 teeth entered the study with periodontitis, observed across 12 dogs aged between 1.3 and 6.9 years. 35 dogs had at least 12 teeth progress to periodontitis within 60 weeks. Of the teeth that progressed to periodontitis, 54% were incisors. The lingual aspect of the incisors was significantly more likely to be affected (p < 0.001). The severity of gingivitis in periodontitis-affected teeth was variable with 24% of the aspects affected having very mild gingivitis, 36% mild gingivitis and 40% moderate gingivitis. Periodontitis progression rate was significantly faster in older dogs. Only one dog (age 3.5) did not have any teeth progress to periodontitis after 60 weeks.ConclusionsThis is the first study to have assessed the progression rate of periodontitis in miniature schnauzers and highlights that with no oral care regime, the early stages of periodontitis develop rapidly in this breed. An oral care regime and twice yearly veterinary dental health checks should be provided from an early age for this breed and other breeds with similar periodontitis incidence rates.

The decision making of dental implants for severely periodontitis-affected teeth

种植修复的高成功率使其成为修复缺失牙的首选.因此,有学者提出对牙周炎患牙进行策略性(proactive或strategic)拔除,以阻止牙槽骨的进一步吸收,理由是牙周炎患牙的治疗是不可预期的,牙周组织的破坏会持续发展,重度牙周炎患牙如果已经发展到牙槽骨严重吸收再拔除将给种植修复带来困难,应在还有一定量的牙槽骨存在时即拔除患牙行种植修复[1].那么,重度牙周炎是否可以通过完善的牙周治疗得到控制?牙周炎的治疗真是不可预期的吗?下面笔者将就重度牙周炎患牙的治疗选择——拔除行种植修复还是通过完善的牙周治疗保留患牙,谈一些个人观点。

Root conditioning in periodontology - Revisited.

Objective:Root surfaces of periodontitis-affected teeth are hypermineralized and contaminated with cytotoxic and other biologically active substances. To achieve complete decontamination of the tooth surfaces, various methods including root conditioning following scaling and root planning are present. The main objective of this article is to throw light on the different root conditioning agents used and the goals accomplished by root conditioning in the field of periodontology.Materials and Methods:20 human maxillary anterior teeth indicated for extraction due to chronic periodontitis were collected and root planned. The teeth were sectioned and specimens were divided into two groups — Group I and II. Group I dentin specimens were treated with EDTA and group II specimens were treated with tetracycline HCl solution at concentration of 10% by active burnishing technique for 3 minutes. The root surface samples were then examined by scanning electron microscope (SEM).Results:The results of the study showed that EDTA and tetracycline HCl were equally effective in removing the smear layer. It was observed that the total and patent dentinal tubules were more in number in teeth treated with tetracycline as compared to EDTA group. However, EDTA was found to be much more effective as root conditioning agent because it enlarged the diameter of dentinal tubules more than that of tetracycline HCl.Conclusion:Results of in-vitro study showed that both the agents are good root conditioning agents if applied in addition to periodontal therapy. However, further studies are required to establish the in-vivo importance of EDTA and tetracycline HCL as root conditioners.

Comparison of the efficacy of ethylenediaminetetraacetic acid and tetracycline hydrochloride as root conditioning agents: An in vitro study

Objective: Root surfaces of periodontitis-affected teeth are hypermineralized and contaminated with cytotoxic and other biologically active substances. Various root conditioning agents have been recommended as an adjunct to mechanical root surface debridement to expose dentin collagen and cementum bound proteins. The aim of the present in vitro study was to compare the efficacy of ethylenediaminetetraacetic acid (EDTA) and tetracycline hydrochloride (HCl) as root conditioning agents on planed root surfaces. Materials and Methods: A total of 20 human maxillary anterior teeth indicated for extraction due to chronic periodontitis were collected and root planed. The teeth were sectioned and specimens were divided into two groups - Group I and II. Group I dentin specimens were treated with EDTA and Group II specimens were treated with tetracycline HCl solution at a concentration of 10% by active burnishing technique for 3 min. The root surface samples were then examined by scanning electron microscope. Results: The results of this study showed that EDTA and tetracycline HCl were equally effective in removing the smear layer. It was observed that the total and patent dentinal tubules were more in number in teeth treated with tetracycline when compared to EDTA group. However, EDTA was found to be much more effective as root conditioning agent because it enlarged the diameter of dentinal tubules more than that of tetracycline HCl. Conclusion: The results of in vitro study showed that both the agents are good root conditioning agents if applied in addition to periodontal therapy. However, further studies are required to establish the in vivo importance of EDTA and tetracycline HCL as root conditioners.

Analysis of microbiota associated with peri-implantitis using 16S rRNA gene clone library

Background: Peri-implantitis (PI) is an inflammatory disease which leads to the destruction of soft and hard tissues around osseointegrated implants. The subgingival microbiota appears to be responsible for peri-implant lesions and although the complexity of the microbiota has been reported in PI, the microbiota responsible for PI has not been identified.Objective: The purpose of this study was to identify the microbiota in subjects who have PI, clinically healthy implants, and periodontitis-affected teeth using 16S rRNA gene clone library analysis to clarify the microbial differences.Design: Three subjects participated in this study. The conditions around the teeth and implants were evaluated based on clinical and radiographic examinations and diseased implants, clinically healthy implants, and periodontally diseased teeth were selected. Subgingival plaque samples were taken from the deepest pockets using sterile paper points. Prevalence and identity of bacteria was analyzed using a 16S rRNA gene clone library technique.Results: A total of 112 different species were identified from 335 clones sequenced. Among the 112 species, 51 (46%) were uncultivated phylotypes, of which 22 were novel phylotypes. The numbers of bacterial species identified at the sites of PI, periodontitis, and periodontally healthy implants were 77, 57, and 12, respectively. Microbiota in PI mainly included Gram-negative species and the composition was more diverse when compared to that of the healthy implant and periodontitis. The phyla Chloroflexi, Tenericutes, and Synergistetes were only detected at PI sites, as were Parvimonas micra, Peptostreptococcus stomatis, Pseudoramibacter alactolyticus, and Solobacterium moorei. Low levels of periodontopathic bacteria, such as Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans, were seen in peri-implant lesions.Conclusions: The biofilm in PI showed a more complex microbiota when compared to periodontitis and periodontally healthy teeth, and it was mainly composed of Gram-negative anaerobic bacteria. Common periodontopathic bacteria showed low prevalence, and several bacteria were identified as candidate pathogens in PI.

Horizontal alveolar bone loss: A periodontal orphan

Background:Attempts to successfully regenerate lost alveolar bone have always been a clinician’s dream. Angular defects, at least, have a fairer chance, but the same cannot be said about horizontal bone loss. The purpose of the present study was to evaluate the prevalence of horizontal alveolar bone loss and vertical bone defects in periodontal patients; and later, to correlate it with the treatment modalities available in the literature for horizontal and vertical bone defects.Materials and Methods:The study was conducted in two parts. Part I was the radiographic evaluation of 150 orthopantomographs (OPGs) (of patients diagnosed with chronic periodontitis and seeking periodontal care), which were digitized and read using the AutoCAD 2006 software. All the periodontitis-affected teeth were categorized as teeth with vertical defects (if the defect angle was ≤45° and defect depth was ≥3 mm) or as having horizontal bone loss. Part II of the study comprised search of the literature on treatment modalities for horizontal and vertical bone loss in four selected periodontal journals.Results:Out of the 150 OPGs studied, 54 (36%) OPGs showed one or more vertical defects. Totally, 3,371 teeth were studied, out of which horizontal bone loss was found in 3,107 (92.2%) teeth, and vertical defects were found only in 264 (7.8%) of the teeth, which was statistically significant (P<.001). Search of the selected journals revealed 477 papers have addressed the treatment modalities for vertical and horizontal types of bone loss specifically. Out of the 477 papers, 461 (96.3%) have addressed vertical bone loss, and 18 (3.7%) have addressed treatment options for horizontal bone loss. Two papers have addressed both types of bone loss and are included in both categories.Conclusion:Horizontal bone loss is more prevalent than vertical bone loss but has been sidelined by researchers as very few papers have been published on the subject of regenerative treatment modalities for this type of bone loss. This study should be an impetus for greater attention to an otherwise ubiquitous periodontal challenge.