Accuracy of cone beam computed tomography in evaluation of palatal mucosa thickness.

AIM: The purpose of this study was to investigate the accuracy of the measurement of palatal mucosa thickness using cone beam computed tomography (CBCT) and to create a conversion formula to evaluate palatal mucosa thickness more accurately. We then evaluated the palatal mucosa thickness in a Japanese population using CBCT and the conversion formula. MATERIALS AND METHODS: We evaluated palatal mucosa thickness in 10 healthy subjects at 15 sites using CBCT, digital impression, and K file. Multiple regression analysis was performed to create a conversion formula to measure thickness accurately. We then obtained CBCT data from 174 patients retrospectively, applied the conversion formula, and evaluated palatal mucosa thickness. RESULTS: Sites of measurement affected measurement error. Measurement using CBCT was 0.34 ± 0.04 mm smaller than actual measurement; therefore, a conversion formula was created. Male, age ≥60 years, and probing pocket depth ≥4 mm had significant and positive associations with palatal mucosa thickness; however, no association was observed between bleeding on probing and palatal mucosa thickness. CONCLUSION: CBCT is useful for the noninvasive and accurate measurement of palatal mucosa thickness.

Ridge Preservation and Augmentation Using a Carbonated Apatite Bone Graft Substitute: A Case Series.

The newly developed mineral carbonated apatite has recently been proposed as a bone graft material for bone regenerative treatment in implant therapy. This case series details the clinical and radiographic outcomes of ridge preservation and ridge augmentation using only carbonated apatite as bone graft material for implant treatment. Twenty patients (36 sites) who required bone regeneration and implant placement were retrospectively assessed. Simultaneous carbonated apatite implant placement was performed using the simultaneous ridge preservation or augmentation approach on 24 sites in 13 patients with sufficient bone quantity for primary stabilization based on preoperative evaluation results. A staged ridge preservation or augmentation approach was used for the remaining 12 sites in seven patients with insufficient bone quantity. The mean regenerated bone height for each treatment method was as follows: simultaneous preservation, 7.4 ± 3.3 mm; simultaneous augmentation, 3.6 ± 2.3 mm; staged preservation, 7.2 ± 4.5 mm; and staged augmentation, 6.1 ± 2.7 mm. The mean regenerated bone width for each treatment method was as follows: simultaneous preservation, 6.5 ± 2.9 mm; simultaneous augmentation, 3.3 ± 2.5 mm; staged preservation, 5.5 ± 1.7 mm; and staged augmentation, 3.5 ± 1.9 mm. Ultimately, the use of carbonated apatite alone as a bone graft material in implant therapy resulted in stable and favorable bone regeneration.

Novel Flowchart Guiding the Non-Surgical and Surgical Management of Peri-Implant Complications: A Narrative Review.

Peri-implant diseases, such as peri-implant mucositis and peri-implantitis, are induced by dysbiotic microbiota resulting in the inflammatory destruction of peri-implant tissue. Nonetheless, there has yet to be an established protocol for the treatment of these diseases in a predictable manner, although many clinicians and researchers have proposed various treatment modalities for their management. With the increase in the number of reports evaluating the efficacy of various treatment modalities and new materials, the use of multiple decontamination methods to clean infected implant surfaces is recommended; moreover, the use of hard tissue laser and/or air abrasion techniques may prove advantageous in the future. Limited evidence supports additional effects on clinical improvement in antimicrobial administration for treating peri-implantitis. Implantoplasty may be justified for decontaminating the implant surfaces in the supracrestal area. Surgical treatment is employed for advanced peri-implantitis, and appropriate surgical methods, such as resection therapy or combination therapy, should be selected based on bone defect configuration. This review presents recent clinical advances in debridement methods for contaminated implant surfaces and regenerative materials for treating peri-implant bone defects. It also proposes a new flowchart to guide the treatment decisions for peri-implant disease.

Comprehensive microbiological findings in peri-implantitis and periodontitis.

AIM: The microbial differences between peri-implantitis and periodontitis in the same subjects were examined using 16S rRNA gene clone library analysis and real-time polymerase chain reaction. MATERIALS AND METHODS: Subgingival plaque samples were taken from the deepest pockets of peri-implantitis and periodontitis sites in six subjects. The prevalence of bacteria was analysed using a 16S rRNA gene clone library and real-time polymerase chain reaction. RESULTS: A total of 333 different taxa were identified from 799 sequenced clones; 231 (69%) were uncultivated phylotypes, of which 75 were novel. The numbers of bacterial taxa identified at the sites of peri-implantitis and periodontitis were 192 and 148 respectively. The microbial composition of peri-implantitis was more diverse when compared with that of periodontitis. Fusobacterium spp. and Streptococcus spp. were predominant in both peri-implantitis and periodontitis, while bacteria such as Parvimonas micra were only detected in peri-implantitis. The prevalence of periodontopathic bacteria was not high, while quantitative evaluation revealed that, in most cases, prevalence was higher at peri-implantitis sites than at periodontitis sites. CONCLUSIONS: The biofilm in peri-implantitis showed a more complex microbial composition when compared with periodontitis. Common periodontopathic bacteria showed low prevalence, and several bacteria were identified as candidate pathogens in peri-implantitis.

Non-surgical treatment for periodontitis and peri-implantitis: longitudinal clinical and bacteriological findings-A case report with a 7-year follow-up evaluation.

The aim of this report is to show that periodontitis and peri-implantitis with horizontal bone resorption in a 68-year-old male patient were successfully treated by non-surgical treatment. Scaling with an ultrasonic device was performed for moderate periodontitis around the mandibular left first premolar and moderate peri-implantitis around the maxillary right molar implants. Root planing with a metal curette was performed for the periodontal site, and debridement with a plastic curette was performed for the peri-implant site. A month after treatment, probing depth decreased from 5 to 2 mm at the periodontal site and 8 to 3 mm at the peri-implant site. The investigation of bacterial composition by sequencing the 16S rRNA gene amplicons showed that the composition similarly changed at both sites, 5 years after treatment; the change reflected the typical recovery of periodontitis. The clinical condition was maintained for 7 years after treatment at both sites. This was a successful case of non-surgical treatment for peri-implantitis with horizontal bone resorption, promoting recovery of the microbiota from dysbiotic shift.

Discrimination of Bacterial Community Structures among Healthy, Gingivitis, and Periodontitis Statuses through Integrated Metatranscriptomic and Network Analyses.

Periodontal disease is an inflammatory condition caused by polymicrobial infection. The inflammation is initiated at the gingiva (gingivitis) and then extends to the alveolar bone, leading to tooth loss (periodontitis). Previous studies have shown differences in bacterial composition between periodontal healthy and diseased sites. However, bacterial metabolic activities during the health-to-periodontitis microbiome shift are still inadequately understood. This study was performed to investigate the bacterial characteristics of healthy, gingivitis, and periodontitis statuses through metatranscriptomic analysis. Subgingival plaque samples of healthy, gingivitis, and periodontitis sites in the same oral cavity were collected from 21 patients. Bacterial compositions were then determined based on 16S rRNA reads; taxonomic and functional profiles derived from genes based on mRNA reads were estimated. The results showed clear differences in bacterial compositions and functional profiles between healthy and periodontitis sites. Co-occurrence networks were constructed for each group by connecting two bacterial species if their mRNA abundances were positively correlated. The clustering coefficient values were 0.536 for healthy, 0.600 for gingivitis, and 0.371 for periodontitis sites; thus, network complexity increased during gingivitis development, whereas it decreased during progression to periodontitis. Taxa, including Eubacterium nodatum, Eubacterium saphenum, Filifactor alocis, and Fretibacterium fastidiosum, showed greater transcriptional activities than those of red complex bacteria, in conjunction with disease progression. These taxa were associated with periodontal disease progression, and the health-to-periodontitis microbiome shift was accompanied by alterations in bacterial network structure and complexity. IMPORTANCE The characteristics of the periodontal microbiome influence clinical periodontal status. Gingivitis involves reversible gingival inflammation without alveolar bone resorption. In contrast, periodontitis is an irreversible disease characterized by inflammatory destruction in both soft and hard tissues. An imbalance of the microbiome is present in both gingivitis and periodontitis. However, differences in microbiomes and their functional activities in the healthy, gingivitis, and periodontitis statuses are still inadequately understood. Furthermore, some inflamed gingival statuses do not consistently cause attachment loss. In this study, metatranscriptomic analyses were used to investigate the specific bacterial composition and gene expression patterns of the microbiomes of the healthy, gingivitis, and periodontitis statuses. In addition, co-occurrence network analysis revealed that the gingivitis site included features of networks observed in both the healthy and periodontitis sites. These results provide transcriptomic evidence to support gingivitis as an intermediate state between the healthy and periodontitis statuses.

Discriminating Microbial Community Structure Between Peri-Implantitis and Periodontitis With Integrated Metagenomic, Metatranscriptomic, and Network Analysis.

Peri-implantitis and periodontitis are both polymicrobial diseases induced by subgingival plaque accumulation, with some differing clinical features. Studies on the microbial and gene transcription activity of peri-implantitis microbiota are limited. This study aimed to verify the hypothesis that disease-specific microbial and gene transcription activity lead to disease-specific clinical features, using an integrated metagenomic, metatranscriptomic, and network analysis. Metagenomic data in peri-implantitis and periodontitis were obtained from the same 21 subjects and metatranscriptomic data from 12 subjects were obtained from a database. The microbial co-occurrence network based on metagenomic analysis had more diverse species taxa and correlations than the network based on the metatranscriptomic analysis. Solobacterium moorei and Prevotella denticola had high activity and were core species taxa specific to peri-implantitis in the co-occurrence network. Moreover, the activity of plasmin receptor/glyceraldehyde-3-phosphate dehydrogenase genes was higher in peri-implantitis. These activity differences may increase complexity in the peri-implantitis microbiome and distinguish clinical symptoms of the two diseases. These findings should help in exploring a novel biomarker that assist in the diagnosis and preventive treatment design of peri-implantitis.

Distinct interacting core taxa in co-occurrence networks enable discrimination of polymicrobial oral diseases with similar symptoms.

Polymicrobial diseases, which can be life threatening, are caused by the presence and interactions of multiple microbes. Peri-implantitis and periodontitis are representative polymicrobial diseases that show similar clinical symptoms. To establish a means of differentiating between them, we compared microbial species and functional genes in situ by performing metatranscriptomic analyses of peri-implantitis and periodontitis samples obtained from the same subjects (n = 12 each). Although the two diseases differed in terms of 16S rRNA-based taxonomic profiles, they showed similarities with respect to functional genes and taxonomic and virulence factor mRNA profiles. The latter-defined as microbial virulence types-differed from those of healthy periodontal sites. We also showed that networks based on co-occurrence relationships of taxonomic mRNA abundance (co-occurrence networks) were dissimilar between the two diseases. Remarkably, these networks consisted mainly of taxa with a high relative mRNA-to-rRNA ratio, with some showing significant co-occurrence defined as interacting core taxa, highlighting differences between the two groups. Thus, peri-implantitis and periodontitis have shared as well as distinct microbiological characteristics. Our findings provide insight into microbial interactions in polymicrobial diseases with unknown etiologies.

Improvement of glycemic control after periodontal treatment by resolving gingival inflammation in type 2 diabetic patients with periodontal disease.

UNLABELLED: Aims/Introduction: Chronic inflammation aggravates glycemic control in patients with type 2 diabetes mellitus. An increase or decrease in the release and activities of various inflammatory mediators, such as tumor necrosis factor (TNF)-α, interleukin (IL)-6, and C-reactive protein (CRP), are presumed to be responsible for inducing insulin resistance. The purpose of the present study was to examine the effects of non-surgical periodontal treatment incorporating topical antibiotics on glycemic control and serum inflammatory mediators in patients with type 2 diabetes mellitus with periodontitis. MATERIALS AND METHODS: Periodontal inflammation and periodontal tissue destruction were evaluated by bleeding on probing (BOP) and the probing pocket depth (PPD), respectively. A total of 41 patients with type 2 diabetes and periodontitis received periodontal treatment with the topical application of antibiotics four times within a 2-month period. A periodontal examination, including PPD and BOP, and venous blood sampling were carried out at baseline and at 2 and 6 months after periodontal treatment. Glycated hemoglobin (HbA1c), and serum levels of high-sensitivity (hs)-CRP, TNF-α and IL-6 were analyzed. RESULTS: A generalized linear model showed significant associations between the change in the HbA1c values at 6 months after periodontal treatment, and the change in the BOP, baseline TNF-α levels and the baseline mean PPD. CONCLUSIONS: As BOP is a marker of total gingival inflammation, these results suggest that non-surgical periodontal therapy with topical antibiotics in patients with mild periodontitis might improve glycemic control by resolving periodontal inflammation. Such treatments might be insufficient for the amelioration of insulin resistance in type 2 diabetic patients with severe periodontitis. This trial was registered with the University Hospital Medical Information Network (no. UMIN000006693). (J Diabetes Invest, doi: 10.1111/j.2040-1124.2012.00209.x, 2012).

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.