Treatment of Unfavorable Intrabony Defects with Autogenous Bone Graft in Combination with Leukocyte- and Platelet-Rich Fibrin or Collagen Membranes: A Non-Inferiority Study

Background and Objectives: Unfavorable intrabony defects (IBDs) are associated with the progression of periodontal disease and tooth loss. Growing scientific evidence has demonstrated the effectiveness of platelet concentrations in periodontal treatment. The aim of our study was to demonstrate the non-inferiority of an autogenous bone graft (ABG) associated with leukocyte- and platelet-rich fibrin (L-PRF) compared to ABG + Collagen Membrane in the treatment of IBDs. Material and Methods: Sixty-four patients with at least one IBD were randomly assigned to two groups: ABG+L-PRF and CM+ABG. Clinical and radiographic evaluations were performed at baseline and 12-month follow-up. Clinical attachment level (CAL), gingival recession (GR), probing pocket depth (PPD), and radiograph defect bone level (DBL) were compared between the two treatments. To evaluate the effectiveness of ABG+L-PRF, a non-inferiority margin of =1 mm (-1 mm for GR) was chosen; a second non-inferiority margin of =0.5 mm (-0.5 mm for GR) was set for clinical relevance. Results: At 12-month follow up, both treatments showed clinical and radiographic improvements. The 90% confidence intervals of the CM+ABG-L-PRF+ABG mean difference for CAL gain (-0.0564 mm [-0.316 to 0.203]), DBL gain (-0.433 mm [-0.721 to -0.145]), and PPD reduction (0.232 mm [0.015 to 0.449]) were below the 0.5 mm non-inferiority margin; the GR increase (0.255 mm [0.0645 to 0.445]) stayed above the -0.5 mm. Conclusions: the L-PRF+ABG treatment of unfavorable IBDs is non-inferior with respect to the CM+ABG therapy for CAL gain, but with a lower GR, a slightly higher PPD, and DBL gain.

Minimally invasive non-surgical periodontal therapy of intrabony defects: A prospective multi-centre cohort study

AIM

To assess the potential benefits of minimally invasive non-surgical therapy (MINST) in teeth with intrabony defects and to explore factors associated with the outcomes.

MATERIALS AND METHODS

A multi-centre trial was conducted in 100 intrabony defects in periodontitis patients in private practice. Steps 1 and 2 periodontal therapy including MINST were provided. Clinical and radiographic data were analysed at baseline and 12 months after treatment, with the primary aim being change in radiographic defect depth at 12 months.

RESULTS

Eighty-four patients completed the 12-month follow up. The mean total radiographic defect depth reduced by 1.42 mm and the defect angle increased by 3° (both p < .05). Statistically significant improvements in probing pocket depth (PPD) and clinical attachment level (CAL) were seen at 12 months compared to baseline (p < .001). Fifty-six defects (66.7%) achieved pocket closure (PPD ≤ 4 mm) and 49 defects (58.3%) achieved the composite outcome (PPD ≤ 4 mm and CAL gain ≥3 mm). Deeper and narrower angled defects were positively correlated with radiographic and clinical improvements, respectively.

CONCLUSIONS

Improvements in clinical and radiographic outcomes were seen after MINST. This study highlights the generalizability and wide applicability of this approach, further supporting its effectiveness in the treatment of intrabony defects.

CLINICAL TRIAL REGISTRATION

NCT03741374. https://clinicaltrials.gov/study/NCT03741374?cond=minimally%20invasive%20non%20surgical%20therapy&locStr=UK&country=United%20Kingdom&distance=50&rank=2.

Elevated subgingival temperature infers high bacterial pathogen counts in severe periodontitis

OBJECTIVES

Periodontal inflammation may be assessed by bleeding on probing and subgingival temperature. This pilot study evaluated the intrapatient relationship between subgingival temperature and selected bacterial groups/species in deep periodontal pockets with bleeding on probing.

MATERIALS AND METHODS

In each of eight adults, an electronic temperature probe identified three "hot" pockets with elevated subgingival temperature and three "cool" pockets with normal subgingival temperature among premolars/molars with 6‒10 mm probing depths and bleeding on probing. Microbial samples collected separately from the hot and cool periodontal pockets were cultured for selected periodontal pathogens.

RESULTS

Hot compared to cool periodontal pockets revealed significantly higher absolute and normalized subgingival temperatures and yielded higher mean proportions of Porphyromonas gingivalis (10.2% for hot vs. 2.5% for cool, p = 0.030) and total red/orange complex periodontal pathogens (48.0% for hot vs. 24.6% for cool, p = 0.012).

CONCLUSIONS

Hot versus cool deep periodontal pockets harbored significantly higher levels of major periodontal pathogens. Subgingival temperature measurements may potentially be useful to assess risk of periodontitis progression and the efficacy of periodontal therapy.

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.

p75NTR antibody-conjugated microspheres: an approach to guided tissue regeneration by selective recruitment of endogenous periodontal ligament cells

Repairing defects in alveolar bone is essential for regenerating periodontal tissue, but it is a formidable challenge. One promising therapeutic approach involves using a strategy that specifically recruits periodontal ligament cells (PDLCs) with high regenerative potential to achieve in situ regeneration of alveolar bone. In this study, we have created a new type of microsphere conjugated with an antibody to target p75 neurotrophin receptor (p75NTR), which is made of nano-hydroxyapatite (nHA) and chitosan (CS). The goal of this design is to attract p75NTR+hPDLCs selectively and promote osteogenesis. In vitro experiments demonstrated that the antibody-conjugated microspheres attracted significantly more PDLCs compared to non-conjugated microspheres. Incorporating nHA not only enhances cell adhesion and proliferation on the surface of the microsphere but also augments its osteoinductive properties. Microspheres effectively recruited p75NTR+ cells at bone defect sites in SD rats, as observed through immunofluorescent staining of p75NTR antibodies. This p75NTR antibody-conjugated nHA/CS microsphere presents a promising approach for selectively recruiting cells and repairing bone defects.

Two-stage method of free gingival graft prior to periodontal regenerative surgery for the treatment of intrabony defects with insufficient keratinised tissue width: a study protocol for an open-label randomised controlled trial

INTRODUCTION

Guided tissue regeneration (GTR) combined with bone grafting for periodontal regenerative surgery has ideal clinical results for intrabony defect. However, some sites of intrabony defects often suffer from insufficient keratinised gingival width, which affects the efficacy and long-term prognosis of periodontal tissue regeneration. Free gingival graft (FGG) is an effective surgical procedure to widen the keratinised gingiva, but there are few clinical studies on FGG prior to GTR combination with bone grafting to improve clinical outcomes.

METHODS

This study is an open-label randomised controlled trial. 68 patients with periodontitis with at least one intrabony defect depth with ≥3 mm are recruited and randomly grouped. In the test group, FGG is performed first, followed by GTR and bone grafting 3 months later; while in the control group, only periodontal tissue regenerative procedures are performed. After completion of all procedures, the patients will be recalled at 3 months, 6 months and 12 months and the relevant clinical and radiographic examinations will be carried out and statistical analysis of the data will also be performed. The present research has received approval from the Ethics Committee of Shanghai Stomatological Hospital (No.2022-007) on 4 August 2022.

DISCUSSION

Exploring the effectiveness of the two-stage approach of FGG prior to periodontal tissue regenerative surgery for the treatment of keratinised gingival width deficient intrabony defects can provide a high-level evidence-based basis for the formulation of relevant treatment strategies in clinical practice.

ETHICS AND DISSEMINATION

The present research has received approval from the Ethics Committee of Shanghai Stomatological Hospital (No.2022-007) on 4 August 2022. The patients will be incorporated into this trial only after their written informed consent has been obtained. The study will be performed according to the 2013 revision of the Helsinki Declaration of 1975. Personal information of all subjects will be stored in the Department of Periodontology of Shanghai Stomatological Hospital. Data of the present research will be registered with the Clinical Trials Registry Platform. Additionally, we will disseminate the results through scientific journals.

TRIAL REGISTRATION

Chinese Clinical Trial Registry, ID: ChiCTR 2200063180. Registered on 1 September 2022.

Efficacy of Guided Tissue Regeneration Using Frozen Radiation-Sterilized Allogenic Bone Graft as Bone Replacement Graft Compared with Deproteinized Bovine Bone Mineral in the Treatment of Periodontal Intra-Bony Defects: Randomized Controlled Trial

(1) Background: The aim of this study was to compare the clinical and radiographic outcomes of guided tissue regeneration (GTR) using two biomaterials as bone replacement grafts in the treatment of periodontal intra-bony defects. (2) Methods: Using a split-mouth design, 30 periodontal intra-bony defects were treated with either frozen radiation-sterilized allogenic bone grafts (FRSABG tests) or deproteinized bovine bone mineral (DBBM, controls) combined with a bioabsorbable collagen membrane in 15 patients. Clinical attachment level gains (CAL-G), probing pocket depth reductions (PPD-R), and radiographic changes in linear defect fill (LDF) were evaluated 12 months postoperatively. (3) Results: The CAL, PPD, and LDF values improved significantly in both groups 12 months after the surgery. However, in the test group, the PPD-R and LDF values were significantly higher compared to the controls (PPD-R 4.66 mm versus 3.57 mm, p = 0.0429; LDF 5.22 mm versus 4.33, p = 0.0478, respectively). Regression analysis showed that baseline CAL was a significant predictor for PPD-R (p = 0.0434), while the baseline radiographic angle was a predictor for CAL-G (p = 0.0026) and LDF (p = 0.064). (4) Conclusions: Both replacement grafts when used for GTR with a bioabsorbable collagen membrane yielded successful clinical benefits in teeth with deep intra-bony defects 12 months postoperatively. The use of FRSABG significantly enhanced PPD reduction and LDF.

Antimicrobial Chemotherapy for Recalcitrant Severe Human Periodontitis

This study evaluated a combined systemic and topical anti-infective periodontal treatment of 35 adults who had experienced ongoing periodontal breakdown following conventional surgical periodontics. The prescribed anti-infective therapy, based on microbiological testing, consisted of a single course of metronidazole plus ciprofloxacin (23 patients), metronidazole plus amoxicillin/clavulanic acid (10 patients), and metronidazole plus ciprofloxacin followed by metronidazole plus amoxicillin/clavulanic acid (2 patients). In addition, the study patients received 0.1% povidone-iodine subgingival disinfection during non-surgical root debridement and daily patient administered oral irrigation with 0.1% sodium hypochlorite. At 1 and 5 years post-treatment, all study patients showed gains in clinical periodontal attachment with no further attachment loss, and significant decreases in pocket probing depth, bleeding on probing, and subgingival temperature. The greatest disease resolution occurred in patients who at baseline harbored predominantly major periodontal pathogens which post-antibiotics became non-detectable and substituted by non-periodontopathic viridans streptococci. The personalized and minimally invasive anti-infective treatment regimen described here controlled periodontitis disease activity and markedly improved the clinical and microbiological status of the refractory periodontitis patients.

Minimally Invasive Non-Surgical Technique in the Treatment of Intrabony Defects-A Narrative Review

Intrabony defects occur frequently in periodontitis and represent sites that, if left untreated, are at increased risk for disease progression. Although resective or repair procedures have been used to treat intrabony defects, aiming at their elimination, the treatment of choice is surgical periodontal regeneration. The development of periodontal regeneration in the last 30 years has followed two distinctive, though totally different, paths. The interest of researchers has so far focused on regenerative materials and products on one side, and on novel surgical approaches on the other side. In the area of materials and products, three different regenerative concepts have been explored namely, barrier membranes, bone grafts, and wound healing modifiers/biologics, plus many combinations of the aforementioned. In the area of surgical approaches, clinical innovation in flap design and handling, as well as minimally invasive approaches, has radically changed regenerative surgery. Recently, a minimally invasive non-surgical technique (MINST) for the treatment of intrabony defects was proposed. Initial clinical trials indicated comparable results to the surgical minimally invasive techniques in both clinical and radiographic outcomes. These results support the efficacy of this treatment approach. The aim of this review is to present the evidence on the application of minimally invasive non-surgical techniques and their efficacy in the treatment of intrabony defects.

Concise evaluation and therapeutic guidelines for severe periodontitis: A public health perspective

The main goal of periodontology is to prevent and arrest gingivitis and periodontitis to avoid tooth loss and focal infection of periodontal origin. Periodontal scaling or flap surgery of moderate-to-severe periodontitis have shortcomings, most likely because removal of herpesviruses and bacterial pathogens in deep periodontal lesions and the adjacent inflamed gingiva requires systemic antimicrobial treatment (or gingivectomy). Valacyclovir (1000 mg twice daily on day 1, and 500 mg twice daily on day 2 and on day 3) is a potent anti-herpesvirus agent. Antibiotic combinations against bacterial pathogens include amoxicillin-metronidazole (250 mg of each, thrice daily for 4 days; for systemically healthy adults) and ciprofloxacin-metronidazole (500 mg of each, twice daily for 4 days; for immunosuppressed individuals and patients exposed to contaminated water and poor sanitation). Supportive antiseptic treatment may consist of 0.1%-0.2% sodium hypochlorite (regular household bleach) as cooling spray in ultrasonic scalers, flosser fluid in oral irrigators, and mouthrinse in patient self-care. The anti-infective treatment described here helps control cases of severe periodontitis and constitutes an exceedingly inexpensive alternative to conventional (mechanical) periodontal therapy.

Oral microbial extracellular DNA initiates periodontitis through gingival degradation by fibroblast-derived cathepsin K in mice

Periodontitis is a highly prevalent disease leading to uncontrolled osteoclastic jawbone resorption and ultimately edentulism; however, the disease onset mechanism has not been fully elucidated. Here we propose a mechanism for initial pathology based on results obtained using a recently developed Osteoadsorptive Fluogenic Sentinel (OFS) probe that emits a fluorescent signal triggered by cathepsin K (Ctsk) activity. In a ligature-induced mouse model of periodontitis, a strong OFS signal is observed before the establishment of chronic inflammation and bone resorption. Single cell RNA sequencing shows gingival fibroblasts to be the primary cellular source of early Ctsk. The in vivo OFS signal is activated when Toll-Like Receptor 9 (TLR9) ligand or oral biofilm extracellular DNA (eDNA) is topically applied to the mouse palatal gingiva. This previously unrecognized interaction between oral microbial eDNA and Ctsk of gingival fibroblasts provides a pathological mechanism for disease initiation and a strategic basis for early diagnosis and treatment of periodontitis.

Three-dimensional radiographic assessment of bone changes around posterior dental implants at native bone site in Gansu Province, Northwest of China: A retrospective cohort study

PURPOSE

The aim of this study was to assess bone density and thickness changed following dental implant placement in the maxillary and mandibular jaws. Also, observe the form of bone loss around the implant and the relationship between preoperative bone density and bone thickness with bone loss around dental implants.

METHODS

65 patients, including 102 dental implants, were assessed in this study. CBCT was utilized to determine the bone condition (bone thickness and density at three levels (sub-crestal bone at 3 mm (CB3), 6 mm (CB6), and 9 mm (CB9)) before implant placement, and 2 to 3 years after placement, also determine the bone loss pattern.

RESULTS

The difference in bone thickness was 0.32 ± 0.50 mm at CB3, 0.18 ± 0.40 mm at CB6, and 0.14 ± 0.07 mm at CB9. The change buccal bone density at CB3, CB6, and CB9 were 344.5 ± 278.9, 260.5 ± 276, and 138.9 ± 313.9 HU, respectively, and the change in lingual bone density was 252.7 ± 247, 179.9 ± 244.1, and 281 ± 4063 HU, respectively. Only the CB3 level showed a significant decrease in bone thickness (p < 0.001), and a change in bone density was observed at the three levels (p < 0.001). The means of vertical and horizontal bone loss were 0.19 ± 0.23 mm and 0.18 ± 0.22 mm, respectively. Splinted or adjacent dental implants have more horizontal bone loss, with statistically significant (p < 0.001). Age, gender, and implant position were not statistically related to the outcome variables. There was a negative correlation between the preoperative status of the bone condition and pattern bone loss, as indicated by Pearson's correlation coefficient.

CONCLUSION

CBCT detected a significant bone thickness decrease was found only at the crestal third. A significant bone density increase was found at three levels around dental implants. Implant areas with higher bone thickness and density had less bone loss.

A two-stage deep learning architecture for radiographic staging of periodontal bone loss

Background

Radiographic periodontal bone loss is one of the most important basis for periodontitis staging, with problems such as limited accuracy, inconsistency, and low efficiency in imaging diagnosis. Deep learning network may be a solution to improve the accuracy and efficiency of periodontitis imaging staging diagnosis. This study aims to establish a comprehensive and accurate radiological staging model of periodontal alveolar bone loss based on panoramic images.

Methods

A total of 640 panoramic images were included, and 3 experienced periodontal physicians marked the key points needed to calculate the degree of periodontal alveolar bone loss and the specific location and shape of the alveolar bone loss. A two-stage deep learning architecture based on UNet and YOLO-v4 was proposed to localize the tooth and key points, so that the percentage of periodontal alveolar bone loss was accurately calculated and periodontitis was staged. The ability of the model to recognize these features was evaluated and compared with that of general dental practitioners.

Results

The overall classification accuracy of the model was 0.77, and the performance of the model varied for different tooth positions and categories; model classification was generally more accurate than that of general practitioners.

Conclusions

It is feasible to establish deep learning model for assessment and staging radiographic periodontal alveolar bone loss using two-stage architecture based on UNet and YOLO-v4.

Enamel matrix derivative as an adjunct to minimally invasive non-surgical treatment of intrabony defects: A randomized clinical trial

AIM

To compare the efficacy of minimally invasive non-surgical technique (MINST) with or without enamel matrix derivative (EMD) in the treatment of intrabony defects ≤7 mm.

MATERIALS AND METHODS

Thirty-six patients were randomly assigned to the two groups. The control group received MINST, while the experimental MINST+EMD. Clinical measurements were recorded at baseline and at 6 and 12 months, and radiographic measurements were made at baseline and 12 months.

RESULTS

All subjects completed the study, 18 in each group. Significant improvements were observed in both groups at 12 months (p < .001) with no differences in mean PD reduction (4.0 ± 1.4 vs. 4.2 ± 1.7 mm), CAL gain (3.5 ± 1.4 vs. 3.4 ± 1.6 mm), and defect resolution (1.9 ± 1.1 vs. 1.8 ± 0.9 mm) for the MINST and the MINST+EMD groups, respectively (p > .05). A trend for greater pocket closure (PD ≤4 mm and no BoP) was achieved with the application of EMD (77.8% vs. 55.6% sites), particularly for sites with baseline PD ≤8 mm (92.3% vs. 69.2% sites), accompanied by an increased number of successful composite outcome results (61.1% vs. 44.4% sites).

CONCLUSIONS

MINST demonstrates significant improvements 12 months after treatment of intrabony defects ≤7 mm. The additional application of EMD does not further improve the mean clinical or radiographic outcomes. This study is registered in ClinicalTrials.gov (NCT03622255).

The effect of non-surgical and surgical mechanical root debridement on infrabony defects: a retrospective study

The aim of this retrospective study was to assess the outcomes of non-surgical and surgical mechanical root debridement for the treatment of infrabony defects and explore potential prognostic factors. Treated infrabony defects followed for at least 1 year were selected. All data pertaining to the clinical outcomes were recorded. Multi-level regression analysis and Cox Proportional-Hazards Models were used to assess the immediate (3-6 months) clinical outcomes, survival of the treated teeth, and factors influencing these results. 132 patients were included in the analysis. The analysis showed 1.42 ± 1.71 and 2.23 ± 1.64 mm in pocket depth (PD) reduction, 0.13 ± 1.83 and 0.08 ± 1.76 mm in clinical attachment level (CAL) gain, and 1.29 ± 1.56 and 2.15 ± 1.33 mm increase in gingival recession (REC) for the non-surgical and surgical groups, respectively. The 5-year survival rates were 93% for the non-surgically and 90% for the surgically treated teeth. Several factors affected clinical outcomes and tooth survival. Within its limitations, the treatment of infrabony defects with non-surgical and surgical mechanical root debridement was found to result in moderate but significant PD reduction, nevertheless, this may also be attributable to the resultant REC.

Tooth loss and radiographic bone loss in patients without regular supportive care: A retrospective study

BACKGROUND

Very few studies have investigated the effect of patient and site factors on periodontal progression and long-term tooth loss in populations with minimal dental care. The aim of this retrospective study was to assess tooth loss and radiographic bone loss over at least 5 years in patients attending a national-health service primary care practice in Sicily and undergoing no regular care.

METHODS

Records of two hundred consecutive patients with at least 5 years follow-up were screened and demographic, clinical and radiographic data were retrieved. Analyses of associations between patient and site factors and tooth loss were performed.

RESULTS

After excluding not suitable patients, a total of 159 patient records with clinical and radiographic data with average 8.6 years follow-up were included. One hundred of these patients had no professional mechanical plaque removal (PMPR) carried out throughout the study follow-up. Nearly 65% of patients lost at least 1 tooth during the follow-up period, with a total of 400 extracted teeth (for periodontal and non-periodontal reasons). The annual tooth loss rate was slightly higher for "no PMPR" (untreated) patients (0.30 teeth/patient/year) compared with patients who had PMPR (0.27 teeth/patient/year). On a patient-level, only reduced frequency of daily tooth brushing was associated with tooth loss at logistic regression, whereas staging, grading and diagnosis of caries were associated with rates of tooth loss/year. At multilevel analysis including patient- and tooth-factors, age, diagnosis of caries and endodontic disease and percentage of bone loss at baseline were associated with tooth loss.

CONCLUSION

This study confirms the importance of tooth brushing, initial bone loss, caries and endodontic disease in predicting tooth survival in a primary care setting.

Pocket resolution in regenerative treatment of intrabony defects with papilla preservation techniques: A systematic review and meta-analysis of randomized clinical trials

AIM

To systematically assess the clinical performance of different approaches for periodontal regeneration of intrabony defects in terms of pocket resolution compared to access surgery with papilla preservation techniques (PPTs).

MATERIAL AND METHODS

Systematic literature searches were conducted on PubMed, EMBASE, and CENTRAL up to April 2020 to identify RCTs on regenerative treatment [guided tissue regeneration (GTR) or enamel matrix derivative (EMD) with or without biomaterials] of intrabony defects using PPTs. Results were expressed as weighted mean percentages (WMP) or risk ratios of pocket resolution at 12 months (considering both final PD ≤ 3 mm and ≤4 mm).

RESULTS

A total of 12 RCTs were included. Based on a final PD ≤ 3 mm or PD ≤ 4 mm, the WMP of pocket resolution was 61.4% and 92.1%, respectively. EMD and GTR obtained comparable results. Pairwise meta-analysis identified a greater probability of achieving pocket resolution for GTR compared to PPTs. The number needed to treat for GTR to obtain one extra intrabony defect achieving PD ≤ 3 mm or PD ≤ 4 mm over PPTs was 2 and 4, respectively.

CONCLUSION

Regenerative surgery represents a viable approach to obtain final PD ≤ 4 mm in the short-term.

Three periodontitis phenotypes: Bone loss patterns, antibiotic-surgical treatment and the new classification

AIM

To compare three periodontitis clusters (A, B and C) for alveolar bone loss (ABL) patterns, antibiotic prescriptions and surgeries and to relate them to the new classification of periodontitis.

MATERIALS AND METHODS

ABL patterns, prescription of systemic antibiotics and the number of surgeries were retrieved for all patients (n = 353) in the clusters. Comparisons and possible predictors for antibiotics were assessed, and results also evaluated in relation to the new classification.

RESULTS

Cluster A is characterized by angular defects often affecting the first molars and localized stage III/IV grade C periodontitis. Cluster B contains mainly localized or generalized stage III/IV, grade C patients. Cluster C contains mainly patients with generalized stage III/IV grade C periodontitis. Patients in cluster A received significantly more antibiotics compared to B and C (78% vs. 23% and 17%); the predictors for antibiotic prescription were young age and localized ABL. No differences in numbers of periodontal surgeries were observed between clusters (A = 1.0 ± 1.4, B = 1.3 ± 1.4 and C = 1.3 ± 1.5).

CONCLUSIONS

Within stage III/IV grade C periodontitis, we could detect three clusters of patients. The distinct localized ABL pattern and younger age in cluster A presumably prompted clinicians to prescribe antibiotics.

Primer on etiology and treatment of progressive/severe periodontitis: A systemic health perspective

Periodontology is an infectious disease-based discipline. The etiopathology of progressive/severe periodontitis includes active herpesviruses, specific bacterial pathogens, and proinflammatory cytokines. Herpesviruses and periodontopathic bacteria may interact synergistically to produce periodontal breakdown, and periodontal herpesviruses may contribute to systemic diseases. The infectious agents of severe periodontitis reside in deep pockets, furcation lesions, and inflamed gingiva, sites inaccessible by conventional (purely mechanical) surgical or nonsurgical therapy but accessible by systemic antibiotic treatment. This brief overview presents an effective anti-infective treatment of severe periodontitis, which includes systemic chemotherapy/antibiotics against herpesviruses (valacyclovir [acyclovir]) and bacterial pathogens (amoxicillin + metronidazole or ciprofloxacin + metronidazole) plus common antiseptics (povidone-iodine and sodium hypochlorite) and select ultrasonic scaling. The proposed treatment can cause a marked reduction or elimination of major periodontal pathogens, is acceptably safe, and can be carried out in minimal time with minimal cost.

Periodontitis in tonsil cancer patients-A comparative study in accordance with tumour p16 status

OBJECTIVES

We assessed the periodontal situation radiologically according to tumour p16 status.

MATERIALS AND METHODS

Patients with a diagnosis of tonsillar cancer and availability of a digital panoramic radiograph (DPR) during a 5-year period were included in this retrospective study. The predictor variables were periodontal stability, marginal bone loss, marginal bone loss without periodontal stability and total number of teeth. Periodontal status was compared with p16 status, age, gender, smoking and alcohol use.

RESULTS

Among 115 patients included in the analyses (p16-negative, n = 24; p16-positive, n = 91), smoking (p < .0001), heavy alcohol use (p < .0001) and total number of teeth (p = .0001) were significantly associated with p16 status. Current smoking (OR = 7.3) and heavy alcohol use (OR = 10.1) increased the risk of p16-negative cancer.

CONCLUSIONS

Patients with p16-negative tonsillar carcinoma had less teeth than patients with p16-positive tumours. Other periodontal findings were common in both groups without statistical significance. Heavy alcohol use and smoking were the most important risk factors for p16-negative tonsillar carcinoma.

Prognostic Factors of Grade 2-3 Endo-Periodontal Lesions Treated Nonsurgically in Patients with Periodontitis: A Retrospective Case-Control Study

Background

Endo-periodontal lesions are bacterial infectious diseases involving both the periodontal and pulp tissues with poor outcomes. It is hard for clinicians to predict their prognosis. The aim of this study is to investigate the factors affecting the prognosis of endo-periodontal lesions.

Methods

A total of 140 teeth diagnosed with grade 2-3 endo-periodontal lesions in patients with periodontitis were recruited in this study. They were divided into high and low responder groups, according to the clinical symptoms and parameters of the teeth involved after nonsurgical treatment of both the endodontic and periodontal components. Clinical parameters and symptoms were compared before and after treatment, and gender, age, smoking, and all clinical parameters were compared between high and low responder groups using univariate analyses. Logistic regression was applied to evaluate the independent effects on endo-periodontal lesion prognosis.

Results

Compared with the clinical parameters at baseline, the values of tooth mobility (TM), periapical index (PAI), and discomfort when chewing were decreased after endodontic therapy, and the values of periodontal probing depth (PD), clinical attachment level (CAL), sulcus bleeding index (SBI), TM, simplified oral hygiene index (OHI-S), full-mouth periodontitis severity, PAI, and discomfort when chewing were decreased after periodontal therapy. Univariate analysis revealed that smoking, PD, CAL, TM, PAI, clinical crown-root ratio (CR), full-mouth periodontitis severities, and the number of root canals were significantly different between the high and low responder groups (P < 0.05). The logistic regression analysis showed that smoking, PD, CAL, full-mouth periodontitis severities, and the number of root canals remained significantly associated with grade 2-3 endo-periodontal lesions in patients with periodontitis (P < 0.05). The logistic regression analysis showed that smoking, PD, CAL, full-mouth periodontitis severities, and the number of root canals remained significantly associated with grade 2-3 endo-periodontal lesions in patients with periodontitis (

Conclusions

and Practical Implications. High PD and CAL, multirooted teeth, smoking, and serious full-mouth periodontitis indicated a poor prognosis for teeth with grade 2-3 endo-periodontal lesions.

Herpesvirus-bacteria synergistic interaction in periodontitis

The etiopathogenesis of severe periodontitis includes herpesvirus-bacteria coinfection. This article evaluates the pathogenicity of herpesviruses (cytomegalovirus and Epstein-Barr virus) and periodontopathic bacteria (Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis) and coinfection of these infectious agents in the initiation and progression of periodontitis. Cytomegalovirus and A. actinomycetemcomitans/P. gingivalis exercise synergistic pathogenicity in the development of localized ("aggressive") juvenile periodontitis. Cytomegalovirus and Epstein-Barr virus are associated with P. gingivalis in adult types of periodontitis. Periodontal herpesviruses that enter the general circulation may also contribute to disease development in various organ systems. A 2-way interaction is likely to occur between periodontal herpesviruses and periodontopathic bacteria, with herpesviruses promoting bacterial upgrowth, and bacterial factors reactivating latent herpesviruses. Bacterial-induced gingivitis may facilitate herpesvirus colonization of the periodontium, and herpesvirus infections may impede the antibacterial host defense and alter periodontal cells to predispose for bacterial adherence and invasion. Herpesvirus-bacteria synergistic interactions, are likely to comprise an important pathogenic determinant of aggressive periodontitis. However, mechanistic investigations into the molecular and cellular interaction between periodontal herpesviruses and bacteria are still scarce. Herpesvirus-bacteria coinfection studies may yield significant new discoveries of pathogenic determinants, and drug and vaccine targets to minimize or prevent periodontitis and periodontitis-related systemic diseases.

Potassium dihydrogen phosphate promotes the proliferation and differentiation of human periodontal ligament stem cells via nuclear factor kappa B pathway

INTRODUCTION

Periodontal ligament stem cells (PDLSCs) are vital for the regeneration of periodontal tissues. Potassium dihydrogen phosphate (KH₂PO₄) has recently been applied as a component of the mineralization inducing medium (MM), which can be used to induce osteogenic differentiation of dental stem cells. However, whether KH₂PO₄ has effects on PDLSCs has not been studied.

MATERIALS AND METHODS

PDLSCs were isolated by magnetic activated cell sorting and cultured. Alkaline phosphatase (ALP) activity and ALP protein expression of PDLSCs treated with different concentrations of KH₂PO₄ were examined to make sure the optimal concentration of KH₂PO₄ for the following experiments. The effects of KH₂PO₄ on the proliferation and differentiation of PDLSCs were investigated by flow cytometry, cell counting kit-8 assay, alizarin red staining, real-time RT-PCR, and Western blot. The involvement of nuclear factor kappa B (NF-κB) pathway in KH₂PO₄-treated PDLSCs was analyzed by Western blot and alizarin red staining.

RESULTS

ALP activity assay and ALP protein expression examination revealed that 1.8 mmol/L KH₂PO₄ was the optimal concentration for the induction of hPDLSCs by KH₂PO₄. The proliferation and mineralization capacity of PDLSCs treated with KH₂PO₄ were enhanced as compared with the control group. PDLSCs treated with KH₂PO₄ showed an improved proliferation capacity in logarithmic growth phase at day 7. As PDLSCs were treated with KH₂PO₄, the expression of odonto/osteogenic markers (OCN/OCN, DSP/DSPP, OSX/OSX, RUNX2/RUNX2, and ALP/ALP) in cells were up-regulated at day 3 or 7. Moreover, the expression of IκBα in cytoplasm was down-regulated, along with an increased expression of p-P65 in cytoplasm and an up-regulated expression of P65 in nucleus. When treated with BMS345541 (the specific NF-κB inhibitor), the odonto/osteogenic differentiation of KH₂PO₄-treated PDLSCs was significantly attenuated.

CONCLUSION

KH₂PO₄ can improve the proliferation and odonto/osteogenic differentiation capacity of PDLSCs via NF-κB pathway, and thus represents a potential target involved in the regeneration of periodontium for clinical treatments.