Periodontopathogen and Epstein-Barr Virus Contamination Affects Transplanted Bone Volume in Sinus Augmentation

Survival Rate of Implants Placed in Residual Bone Height Less than 4.5 Millimeters with or without Bone Grafting Using Summers Method

The aim of this retrospective study is to analyze the survival rate of implants placed in residual bone height (RBH) less than 4.5 mm during an overall follow-up of 5 years, by using Straumann and Astra implant designs with or without sinus bone grafting. A total of 77 patients were examined and treated in two private practices in the regions of Hamra and Jounieh, Lebanon, by two periodontists from 2009 to 2019. These patients received 104 implants (83 Straumann implants and 21Astra implants) where 94 implants underwent osteotomy sinus floor elevation with bone graft and 10 implants without bone graft. The radiographic images were analyzed by three examiners: two periodontists and one oral radiologist. Written informed consents were obtained from all patients prior to treatment. All patients had to fulfill the inclusion criteria elaborated hereinafter. A total of 75.96% of implants were placed at the molars sites and 24.04% at the premolars sites. All 104 implants were clinically stable except 2 Straumann implants which suffered early failure (before the implant loading) and 1 Straumann implant late failure (3 months after the implant loading). All the failed implants were placed in a RBH > 4 mm. The cumulative success rate was 97.12% during an overall follow-up of 5 years. The crestal approach for maxillary sinus floor elevation is a viable technique that can be used in patients with minimal RBH < 4.6 mm.

In vitro effect of Porphyromonas gingivalis combined with influenza A virus on respiratory epithelial cells

OBJECTIVE

Respiratory epithelial cells are the first natural barrier against bacteria and viruses; hence, the interactions among epithelial cells, bacteria, and viruses are associated with disease occurrence and development. The effect of co-infection by P. gingivalis and influenza A virus (IAV) on respiratory epithelial cells remains unknown. The aim of this study was to analyze in vitro cell viability and apoptosis rates in respiratory epithelial A549 cells infected with P. gingivalis or IAV alone, or a combination of both pathogens.

DESIGN

A549 cells were first divided into a control group, a P. gingivalis group, an IAV group, and a P. gingivalis + IAV group, to examine cell viability and apoptosis rates, the levels of microtubule associated protein 1 light chain 3 B (LC3-II), microtubule associated protein 1 light chain 3A (LC3-I), and sequestosome 1 (P62), and the formation of autophagosomes. The autophagy inhibitor, 3-methyladenine (3MA), was used to assess autophagy and apoptosis in A549 cells infected with P. gingivalis or IAV.

RESULTS

An MTT assay revealed that cell viability was significantly lower in the IAV group than in the P. gingivalis + IAV group (P < 0.05). Flow cytometry indicated that the apoptosis rate was significantly higher in the IAV group than in the P. gingivalis + IAV group (P < 0.05). The fluorescence levels of GFP-LC3 increased significantly, the LC3-II/LC3-I ratio was significantly higher, and the P62 protein levels were statistically lower in the P. gingivalis + IAV group compared with the IAV group (all P < 0.05). Western blotting revealed that the LC3- II/LC3-I ratio was significantly lower, and caspase-3 levels were significantly higher in the 3MA + P. gingivalis + IAV group compared to the P. gingivalis + IAV group (all P < 0.05).

CONCLUSION

In vitro studies showed that infection by P. gingivalis combined with IAV temporarily inhibited apoptosis in respiratory epithelial cells, and this may be related to the initiation of autophagy.

Prevalence of Epstein-Barr virus DNA and Porphyromonas gingivalis in Japanese peri-implantitis patients

Background

Peri-implantitis (PI) is an inflammatory reaction associated with functional deterioration of supporting bones around the dental implant. Recent studies suggested Epstein–Barr virus (EBV) is involved in the pathogenesis of periodontitis. We investigated the association between EBV and Porphyromonas gingivalis in Japanese PI patients.

Methods

Fifteen periodontally healthy individuals, 15 healthy implant patients and 15 PI patients were recruited. Forty five subgingival plaque samples were collected from the deepest probing pocket depth (PPD) site from each patient. Real-time PCR was used to detect EBV DNA and P. gingivalis.

Results

EBV and P. gingivalis were detected in 7 and 3 PPD sites of the healthy controls, in 9 and 4 PPD sites of the healthy implants, and in 13 and 14 PPD sites of the PI patients. P. gingivalis and coexistence of EBV and P. gingivalis were detected significantly higher in the PI patients than healthy controls and healthy implant patients. EBV was detected significantly higher in the PI patients than healthy controls.

Conclusions

Higher levels of EBV and P. gingivalis were detected in PPD sites of PI patients. These results suggest that coexistence of EBV and P. gingivalis may serve pathogenic factors cause for PI in Japanese dental patients.

Plant-derived pectin nanocoatings to prevent inflammatory cellular response of osteoblasts following Porphyromonas gingivalis infection

Background

Bioengineered plant-derived Rhamnogalacturonan-Is (RG-Is) from pectins are potential candidates for surface nanocoating of medical devices. It has recently been reported that RG-I nanocoatings may prevent bacterial infection and improve the biocompatibility of implants. The aim of the study was to evaluate in vitro impact of bioengineered RG-I nanocoatings on osteogenic capacity and proinflammatory cytokine response of murine osteoblasts following Porphyromonas gingivalis infection.

Methods

Murine MC3T3-E1 osteoblasts and isolated primary calvarial osteoblasts from C57BL/6J (B6J osteoblasts) mice were infected with P. gingivalis and incubated on tissue culture polystyrene plates with or without nanocoatings of unmodified RG-Is isolated from potato pulps (PU) or dearabinanated RG-Is (PA). To investigate a behavior of infected osteoblasts cultured on RG-Is cell morphology, proliferation, metabolic activity, mineralization and osteogenic and pro-inflammatory gene expression were examined.

Results

Following P. gingivalis infection, PA, but not PU, significantly promoted MC3T3-E1 and BJ6 osteoblasts proliferation, metabolic activity, and calcium deposition. Moreover, Il-1b, Il-6, TNF-α, and Rankl gene expressions were downregulated in cells cultured on PU and to a higher extent on PA as compared to the corresponding control, whereas Runx, Alpl, Col1a1, and Bglap gene expressions were upregulated vice versa.

Conclusion

Our data clearly showed that pectin RG-Is nanocoating with high content of galactan (PA) reduces the osteoblastic response to P. gingivalis infection in vitro and may, therefore, reduce a risk of inflammation especially in immunocompromised patients with rheumatoid or periodontal disorders.

Systemic antibiotics and the risk of superinfection in peri-implantitis

Peri-implantitis has emerged in the last few years as a complication difficult to resolve. The etiopathogenesis consensus is mainly attributed to bacteria. Following the preferred reporting items for systematic reviews and meta-analysis (PRISMA) guidelines, a PubMed/Medline literature search was performed using the US National Library of Medicine database up to 2015 to analyze available scientific data on the rationale and risk of superinfection associated to systemic antimicrobials in human peri-implant disease. A hand search was also conducted on relevant medical and microbiology journals. The methodological index for non-randomized studies (MINORS) was independently assessed for quality on the selected papers. Proposed combined therapies use broad-spectrum antibiotics to halt the disease progression. A major associated risk, particularly when prescribed empirically without microbiological follow-up, is the undetected development of superinfections and overgrowth of opportunistic pathogens difficult to eradicate. Peri-implant superinfections with opportunistic bacteria, yeast and viruses, are plausible risks associated to the use of systemic antibiotics in immunocompetent individuals. Lack of microbiological follow-up and antibiotic susceptibility testing may lead to ongoing microbial challenges that exacerbate the disease progression. The increased proliferation of antimicrobial resistance, modern implant surface topography and indiscriminative empiric antibiotic regimens may promote the escalation of peri-implant disease in years to come. A personalized 3-month supportive therapy may help prevent risks by sustaining a normal ecological balance, decreasing specific pathogen proportions and maintaining ideal plaque control.

Transcrestal Sinus Lift Procedure Approaching Atrophic Maxillary Ridge: A 60-Month Clinical and Radiological Follow-Up Evaluation

Aim. The aim of this study was to assess the success and the survival rate of dental implants placed in augmented bone after sinus lifting procedures. Material and Methods. 31 patients were mainly enrolled for a residual upper jaw crest thickness of 3 mm. CBCT scans were performed before and after the augmentation technique and at the follow-up appointments, at 3, 6, 12, 24, and up to 60 months. The follow-up examination included cumulative survival rate of implants, peri-implant marginal bone loss, and the height of sinus floor augmentation. Results. This retrospective study on 31 patients and 45 implants later inserted in a less than 3 mm crest showed excellent survival rates (99.5%), one implant was lost before loading due to an acute infection after 24 days, and two implants did not osteointegrate and were removed after 3 months. The radiological evaluation showed an average bone loss of 0.25 mm (±0.78 mm) at the first follow-up appointment (3 months) up to 0.30 mm (±1.28 mm) after 60-month follow-up. Conclusion. In this study it was reported how even in less than 3 mm thick crest a transcrestal technique can predictably be used with a long-term clinical and radiological outcome, giving patients excellent stability of the grafted material and healthy clinical results.

Crestal approach for maxillary sinus augmentation in patients with ≤ 4 mm of residual alveolar bone

PURPOSE

Less morbidity is the major advantage to a one-stage crestal approach to maxillary sinus elevation. However, the ability to ensure high primary implant stability in a severely atrophied ridge is of chief concern. The purpose of this study is to measure and compare the success rate of implants placed at the time of crestal approach sinus lift in patients with ≤ 4 mm of residual alveolar bone (RAB) and >4 mm of RAB.

MATERIALS AND METHODS

In this three-site multicenter study, one hundred two patients, 53 males and 49 females, (23-89 years old; mean = 56.2) were evaluated. Three experienced surgeons (>15 years) performed the crestal approach sinus lift microsurgeries with simultaneous implant placement. At baseline and at the follow-up appointments, calibrated examiners measured radiographic interproximal bone level using ImageJ for Windows after calibration of the radiographs. References for the bone level measurements were the platform, first and second threads of the implants. Statistical analyses, using STATA version 12, stratified patients according to RAB height (group 1: RAB of ≤ 4 mm; n = 35 and group 2: RAB > 4 mm; n = 67), age, gender, and treatment center.

RESULTS

The success rate was 100% for group 1 and 98.51% for group 2 at 6 to 100 months postprosthetic loading (mean = 29.7 months). The peri-implant bone loss averaged 0.55 mm (interquartile range [IQR] = 0.5 [0-1]) in group 1 and 0.07 mm (IQR = 0 [0-0]) in group 2. There was no statistically significant difference between the two groups. Clinical outcomes were independent of age, gender, and treatment center.

CONCLUSIONS

The RAB height did not increase crestal bone loss or reduce the success rate of the implants and associated prostheses. The crestal approach should be considered a viable technique for use in patients with residual bone height of ≤ 4 mm and merits further evaluation.