Dysbiotic relationship between arthritis and the oral-gut microbiome. A critical review.

Arthritis and prosthetic joint infections (PJIs) overall are associated with reduced quality of life and limited work capacity. Multiple, overlapping factors contribute to these conditions. Some investigations have suggested a dysbiotic association between the oral-gut microbiome and pathogenesis of arthritis and PJIs. A better understanding of the role of the oral-gut microbiota in arthritis and PJI pathophysiology can shed light into how its disequilibrium can discharge a pro-inflammatory response, and impact the health of patients susceptible to arthritis or with established joint disease. A review of published in vivo and clinical data suggested that alterations in oral and gut microbiota can lead to a disturbance of immunoregulatory properties, and may be associated with joint infections and arthritis. This review brings new insights into the current status of the evidence on the potential molecules and inflammatory biomarkers disrupted by an oral-gut microbial dysbiosis. Normal commensals and pathogenic oral and gut microflora homeostasis are important not only to prevent infections per se but also its potential progression. Further experiments, especially controlled clinical trials, are needed to ascertain how microbiome manipulation and other microbiota-directed approaches can help control inflammation and effectively prevent and treat arthritic diseases. Additionally, studies on the effects of the long-term oral diseases, such as chronic periodontitis, on arthritis and PJIs need to be conducted.

The Influence of Tactile Perception on Classification of Bone Tissue at Dental Implant Insertion.

BACKGROUND: Various ways of using the Lekholm and Zarb (L&Z) classification have added to the lack of scientific evidence of the effectiveness of this clinical method in the evaluation of implant treatment. PURPOSE: The study aims to assess subjective jawbone classifications in patients referred for implant treatment, using L&Z classification with and without surgeon's hand perception at implant insertion. The association between bone type classifications and quantitative parameters of primary implant stability was also assessed. MATERIALS AND METHODS: One hundred thirty-five implants were inserted using conventional loading protocol. Three surgeons classified bone quality at implant sites using two methods: one based on periapical and panoramic images (modified L&Z) and one based on the same images associated with the surgeon's tactile perception during drilling (original L&Z). Peak insertion torque and implant stability quotient (ISQ) were recorded. RESULTS: The modified and original L&Z were strongly correlated (rho = 0.79; p < .001); Wilcoxon signed-rank test showed no significant difference in the distribution of bone type classification between pairs using the two methods (p = .538). Spearman correlation tested the association between primary stability parameters and bone type classifications (-0.34 to -0.57 [p < .001]). CONCLUSIONS: Tactile surgical perception has a minor influence on rating of subjective bone type for dental implant treatment using the L&Z classification.

Bone tissue microarchitectural characteristics at dental implant sites part 2: correlation with bone classification and primary stability.

OBJECTIVE: To investigate in vivo the correlation between the bone microarchitecture of implant bone sites, bone tissue classification subjectively assessed in radiographs and primary implant stability. MATERIAL AND METHODS: Periapical and panoramic radiographs were obtained from 32 partially edentulous patients. Three surgeons classified bone quality at implant sites using two different methods: assessments in periapical and panoramic radiographs (PP) and according to the classification proposed by Lekholm and Zarb (L&Z). During the implant insertion, bone biopsies were taken, and three-dimensional parameters were measured by microcomputed tomography (microCT). Insertion torque value (ITV) and initial implant stability quotient (ISQ) were recorded at the moment of the implantation. ISQ was also recorded at the uncovering stage of a traditional implant protocol. RESULTS: Bone types 2 and 3 were the most prevalent classifications according to PP (54.3%) and L&Z (58.7%). The mean and standard deviation values of primary stability variables were 38.7(16.7) for ITV, 75.3 (7.7) for initial ISQ and 79.3 (6.8) for uncovering ISQ. Several microCT original and factor variables were found to correlate with bone tissue classifications and primary stability variables. L&Z correlated with architecture (r = 0.31; P < 0.05), density (r = -0.43; P < 0.01) and bulk (r = -0.35; P < 0.05), whereas ITV correlated with architecture (r = -0.40; P < 0.01) and density (r = 0.51; P < 0.01). Multiple linear regression analysis revealed that density and bulk explained 32% of the variability of L&Z bone classification, while density and architecture explained 42% of the variability of ITV. CONCLUSIONS: This study demonstrates the first step in validating L&Z classification. MicroCT provides objective and detailed quantitative data on bone microarchitecture. Intraosseous implant stability is mainly determined by the density of the bone. ITVs could be a good indicator of primary implant stability, whereas ISQs measurements have some limitations and should not be used alone.

Bone tissue microarchitectural characteristics at dental implant sites. Part 1: identification of clinical-related parameters.

OBJECTIVE: To identify the characteristics of bone tissue microarchitecture by microCT at dental implant bone sites, describing them in terms of clinical parameters. MATERIAL AND METHODS: Forty-six bone implant sites of the maxilla and mandible from 32 volunteers were evaluated by conventional radiographs and CT scans. During the installation of each implant, bone biopsies were removed using a trephine bur at the first drilling to prepare the socket implant. Each sample was evaluated by microCT and dimensional parameters measured. RESULTS: Factor analysis summarized the microparameters into four components, which accounted for 92.8% of the total variance. The identified factors were (1) architecture - variables affecting 3D trabecular bone configuration and organization, (2) density - variables relating to surface/volume ratios and volume/volume ratios, (3) bulk - variables relating to the amount of bone and (4) spacing - variable related to the distance between trabeculae and the quantity and organization of marrow spaces. CONCLUSION: These four summarized factors correspond to clinical and radiographically recognizable parameters used for routine bone quality evaluation for implant treatment planning, which can potentially influence the primary stability of dental implants. The understanding of factors related to bone microarchitecture might reveal important aspects of its mechanical properties, essential for implant success.

Assessments of trabecular bone density at implant sites on CT images.

OBJECTIVES: To evaluate the association between trabecular bone density measurements of potential implant sites made on axial DICOM images (DentaCT software) and on the same images with eFilm workstation, to correlate bone densities in Hounsfield units (HU) with subjective classification, and to establish a quantitative scale for each bone quality class. STUDY DESIGN: Twenty-seven maxillary and 27 mandibular computed tomographic (CT) examinations of 75 potential implant sites were selected. Trabecular bone density was evaluated with DentaCT and eFilm. Bone quality was subjectively evaluated by 2 examiners. Descriptive statistics, between- and within-group comparison, correlation analysis, and Bland-Altman plot were used for data analysis. RESULTS: DentaCT measurements were higher than eFilm (P < .001). Bone type 2 was the most prevalent, and bone density was significantly reduced from bone types 1 to 4. Quantitative parameters ranged as follows: bone type 4 <200 HU, bone types 2 and 3 >200 to <400 HU, and bone type 1 >400 HU. CONCLUSION: Different qualities of bone can be found in any of the anatomical regions studied (anterior and posterior sites of maxilla and mandible), which confirms the importance of a site-specific bone tissue evaluation prior to implant installation.

A comparison between cutting torque and resonance frequency in the assessment of primary stability and final torque capacity of standard and TiUnite single-tooth implants under immediate loading.

PURPOSE: In this study, standard Brånemark System implants and Brånemark TiUnite implants were evaluated regarding primary stability and placement torque. The correlation between placement torque and primary stability as well as the influence of implant design on placement torque and primary stability were examined. MATERIALS AND METHODS: Twelve patients who presented bilateral loss of either maxillary lateral incisors or premolars were treated with 24 immediately loaded dental implants. Each patient received 1 standard 3.75 x 13-mm Brånemark System implant and one 3.75 x 13-mm TiUnite Mk III implant. One at a time, each implant was connected by a transducer to an Osstell machine that automatically translated a resonance frequency value for the implant into an implant stability quotient value. Osseocare equipment was used to measure the placement torque for both types of implants. RESULTS: Statistical analysis showed higher mean values for standard implants in relation to placement torque and resonance frequency values. DISCUSSION: There was no overall correlation between placement torque and resonance frequency values; this finding supported previous studies. CONCLUSION: Stability was shown to be higher for the standard implants. Mean values of torque resistance were higher for the standard implants than for the TiUnite implants. Implant design appeared to influence primary stability and placement torque.