Probiotics for oral health: do they deliver what they promise?

Probiotics have demonstrated oral health benefits by influencing the microbiome and the host. Although promising, their current use is potentially constrained by several restrictions. One such limiting factor lies in the prevailing preparation of a probiotic product. To commercialize the probiotic, a shelf stable product is achieved by temporarily inactivating the live probiotic through drying or freeze drying. Even though a lyophilized probiotic can be kept dormant for an extended period of time, their viability can be severely compromised, making their designation as probiotics questionable. Additionally, does the application of an inactive probiotic directly into the oral cavity make sense? While the dormancy may allow for survival on its way towards the gut, does it affect their capacity for oral colonisation? To evaluate this, 21 probiotic product for oral health were analysed for the number of viable (probiotic), culturable (CFU) and dead (postbiotic) cells, to verify whether the commercial products indeed contain what they proclaim. After isolating and uniformly lyophilizing three common probiotic species in a simple yet effective lyoprotective medium, the adhesion to saliva covered hydroxyapatite discs of lyophilized probiotics was compared to fresh or reactivated lyophilized probiotics. Unfortunately, many of the examined products failed to contain the claimed amounts of viable cells, but also the strains used were inadequately characterized and lacked clinical evidence for that unknown strain, questioning their label of a 'probiotic'. Additionally, lyophilized probiotics demonstrated low adhesive capacity compared to their counterparts, prompting the question of why fresh or reactivated probiotics are not currently used.

Inflammation as a link between periodontal disease and obesity.

Nutrition plays a critical role in the homeostatic balance, maintenance of health, and longevity. There is a close link between inflammatory diseases and nutritional health. Obesity is a severe pathological process with grave implications on several organ systems and disease processes, including type 2 diabetes, cardiovascular disease, osteoarthritis, and rheumatoid arthritis. The impact of obesity on periodontal inflammation has not been fully understood; the association between nutritional balance and periodontal inflammation is much less explored. This review is focused on the potential mechanistic links between periodontal diseases and obesity and common inflammatory activity pathways that can be pharmacologically targeted.

Clinical and biochemical evaluation of oral irrigation in patients with peri-implant mucositis: a randomized clinical trial.

OBJECTIVE: This randomized clinical trial aimed to compare the efficacy of an oral irrigator and an interdental brush in patients with peri-implant mucositis clinically and biochemically at different time points (at baseline and at the 2nd, 4th, and 12th weeks). MATERIALS AND METHODS: Forty-five patients with at least one implant with peri-implant mucositis were included in the present study (n = 45). The patients were divided into three groups: oral irrigator + toothbrush (OI group, n = 15), interdental brush + toothbrush (IB group, n = 15), and toothbrush only (control) (C group, n = 15). The modified plaque index (mPlI), modified sulcus bleeding index (mSBI), probing pocket depth (PPD), probing attachment level (PAL), and bleeding on probing (BOP) were recorded at baseline and at the 2nd, 4th, and 12th weeks. The levels of interleukin 1 beta (IL-1ß), transforming growth factor-beta (TGF-ß), tissue-type plasminogen activator (t-PA), and plasminogen activator inhibitor-1 (PAI-1) were also determined in the peri-implant crevicular fluid samples biochemically. RESULTS: The mSBI and t-PA at the 2nd week (p = 0.003; p = 0.003); the mPlI, mSBI, BOP, t-PA, and PAI-1 at the 4th week (p < 0.05; p < 0.001; p < 0.001; p = 0.015; p = 0.011); and the mPlI, mSBI, IL-1ß, t-PA, and PAI-1 at the 12th week (p < 0.05; p < 0.001; p = 0.013; p < 0.001; p = 0.002) were significantly lower in the OI group compared with those in the C group. Meanwhile, PAI-1 at the 2nd week, mSBI at the 4th week, and t-PA at the 12th week were significantly lower in the OI group compared with those in the IB group (p < 0.001; p = 0.011; p = 0.003). At the 2nd, 4th, and 12th weeks, all other parameters were not statistically different in the three groups. CONCLUSION: The clinical indexes (such as mSBI and BOP) that play an important role in the diagnosis of peri-implant mucositis showed the lowest means (although limited) in the OI group at all evaluation time points. Moreover, when the clinical and biochemistry results were interpreted altogether, it became apparent that the OI group exhibited similar or more effective results than the IB group in resolving peri-implant mucositis. In light of the foregoing, this study concluded that the use of an oral irrigator can be as effective as an interdental brush in interdental cleaning. CLINICAL RELEVANCE: In this study, it is suggested that the regular use of an oral irrigator along with a toothbrush could be an appropriate alternative to other oral hygiene products such as dental floss and interdental brush for the management of peri-implant mucositis by preventing the accumulation of dental plaque (NCT03844035).

Hypoxia-induced endothelial cell responses - possible roles during periodontal disease.

Background and objective Inflammatory periodontal pockets are known to be hypoxic. Hypoxia influences vascular response to periodontal inflammation, including angiogenesis, which is critical for oxygen and nutrient delivery to periodontal tissues and granulation tissue formation. Our previous work suggests that periodontal bacteria may actively contribute to pocket hypoxia. Herein, we test the hypothesis that Fusobacterium nucleatum actively induces low oxygen tension, which modulates angiogenesis and endothelial cell activity. HUVEC cells were incubated in 1.5% oxygen for (Folkman & Shing, 1992)48 hours. Cell proliferation was measured by MTT; surface expression of CD31, CD34 and VEGF receptors (VEGFR1, VEGFR2) were analyzed by FACS. mRNA expression of HIF isoforms, iNOS, eNOS, COX-2, and VEGF was measured by quantitative PCR. Supernatants were analyzed for the release of IL-1α, TNF-α, and VEGF by ELISA or multiplex immunoassays and nitric oxide was measured by colorimetric assay. F. nucleatum actively depleted oxygen. Hypoxia resulted in a significant increase of HIF isoforms. iNOS was increased while nitric oxide was unchanged. VEGF release was increased at 4 hours followed by an increase in VEGFR1 at 12 hours, but not VEGFR2. CD31 expression was reduced and CD34 was increased after 48 hours (p < 0.05). IL-1α and TNF-α release were decreased at 4 hours (p < 0.05), but both increased by 24 hours; TNF-α increased at 24 h. The data highlight the role of hypoxia in endothelial cell inflammatory changes. F. nucleatum, considered a bridging species in the development of periodontopathic biofilms induces hypoxia in the periodontium leading to angiogenic changes in periodontal disease pathogenesis.

Oral hygiene habits and oral health status of female adolescents under state protection: a pilot study.

PURPOSE: The aim of this study is to evaluate oral health status and oral hygiene practices of female adolescents under state protection. SUBJECTS AND METHODS: Fifty-five female participants between the age of 12 and 18 who are under the care of The Child Protection Institution were included in this study. Self-administered questionnaires were used to obtain information regarding knowledge of oral health and habits. Dental caries status was scored according to the criteria of the World Health Organization (WHO), using the indices of Decayed (D), Missing (M), Filled (F), Surfaces (S) (DMFS). In addition, Gingival Index (GI) and Plaque Index (PI) were recorded during periodontal assessment. Data was statistically analyzed by using Oneway analysis of variance, Tukey's HSD and Student's t tests. RESULTS: Fourteen children had dental fear and 52.7% of them were not satisfied with their esthetic appearance. Although 78.2% of the children knew that brushing prevents dental caries, only 18 of them were brushing regularly twice per day. Mean DMFS, GI and PI scores were 13.18±5.68, 1.35±0.37 and 1.33±0.45, respectively. Only 20% of the children were using dental floss. There was statistically no significant difference between the DMFS scores of the children in terms of flossing. However, the difference between the mean GI and PI of the same group was found to be statistically significant (p<0.05). CONCLUSION: Children under state protection were found to have a reasonable knowledge of the causes of dental caries and gum bleeding. Therefore, adequate management of this positive attitude can significantly improve the oral health of this population.

Endothelial Cell Response to Fusobacterium nucleatum.

Vascular response is an essential aspect of an effective immune response to periodontal disease pathogens, as new blood vessel formation contributes to wound healing and inflammation. Gaining a greater understanding of the factors that affect vascular response may then contribute to future breakthroughs in dental medicine. In this study, we have characterized the endothelial cell response to the common bacterium Fusobacterium nucleatum, an important bridging species that facilitates the activity of late colonizers of the dental biofilm. Endothelial cells were infected with Fusobacterium nucleatum (strain 25586) for periods of 4, 12, 24, or 48 h. Cell proliferation and tube formation were analyzed, and expression of adhesion molecules (CD31 and CD34) and vascular endothelial growth factor (VEGF) receptors 1 and 2 was measured by fluorescence-activated cell sorter (FACS) analysis. Data indicate that F. nucleatum impaired endothelial cell proliferation and tube formation. The findings suggest that the modified endothelial cell response acts as a mechanism promoting the pathogenic progression of periodontal diseases and may potentially suggest the involvement of periodontopathogens in systemic diseases associated with periodontal inflammation.

Gingival crevicular fluid levels of neuropeptides following dental restorations.

PURPOSE: Local neuropeptide release has a critical role in the initiation and progression of an inflammatory response. This study investigated the effects of different restorative materials on periodontium in this regard, by evaluating their neuropeptide-producing effects on gingival crevicular fluid (GCF). METHODS: The study included 14 patients suitable for metal-ceramic, composite and amalgam restorations. Four weeks after periodontal therapy, the restorations were performed. Study groups were constituted regarding the tooth/restoration surfaces contacting gingiva in each patient: 1 ceramic surface of a metal-ceramic crown (ceramic group), its opposite metal surface (metal group), 1 composite surface (composite group), its opposite enamel surface (opposite-composite group), 1 amalgam surface (amalgam group), its opposite enamel surface (opposite-amalgam group) and 1 nonrestored enamel surface (enamel group). Four weeks after dental restorations, clinical data and GCF were obtained from the group sites. Clinical data, GCF volume and its proinflammatory cytokine profile were utilized to evaluate the periodontal health. GCF levels of substance P (SP), neurokinin A (NKA) and calcitonin-gene related peptide (CGRP) were determined by ELISA for revealing the neuropeptide levels. RESULTS: GCF volume was found to increase in all groups compared with the enamel group (p<0.05). SP and NKA levels were higher in the ceramic, composite and amalgam groups than those in the enamel group (p<0.05). SP and NKA levels were also higher in the composite and amalgam groups than those in the opposite-composite/amalgam groups (p<0.05). CONCLUSIONS: These results suggest that ceramic, composite and amalgam materials may uniquely trigger local neuropeptide release in periodontium.

Long-term clinical results on the use of platelet concentrate in the treatment of intrabony periodontal defects.

OBJECTIVE: The purpose of this clinical investigation was to evaluate long-term results obtained with the combination of platelet pellet (PP) plus bioabsorbable barrier membrane (BM) and to compare this outcome with the results obtained using bioactive glass (BG) graft material with a BM. MATERIALS AND METHODS: Using a split mouth design, 11 chronic periodontitis patients (power ≥ at least 80%) were randomly assigned to treatment with a combination of PP/GTR or BG/GTR in contra-lateral dentition areas. Clinical attachment level (CAL) as the primary outcome variable, calculated as the sum of probing pocket depth (PPD) and gingival recession, and radiological alveolar bone level were recorded at baseline, 6 months and 5 years. RESULTS: There were no statistical differences between test and control defects at baseline. PPD reductions and CAL and radiological alveolar bone height gains were statistically significant between baseline and 6 months and between baseline and 5 years in both groups (p < 0.01). Six months results of frequency distribution showed that 82% of the defects attained ≥ 4 mm CAL gain in both groups, while 5 year results showed that 73% of the defects attained 2 mm ≤ CAL gain < 4 mm in the PP/BM group and 55% of the defects attained 2 mm ≤ CAL gain < 4 mm in the BG/BM group. All parameters evaluated showed no significant differences between 6 months and 5 years in both groups (p > 0.05). No statistically significant difference in any of the clinical parameters was observed at 6 months and 5 years between the groups (p > 0.05). CONCLUSIONS: The long-term efficacy of platelet concentrate combined with a barrier membrane is similar with the combination of bioactive glass graft material and barrier membrane, suggesting that results obtained with both treatment approaches can be maintained over a period of 5 years.

Autogenous cortical bone and bioactive glass grafting for treatment of intraosseous periodontal defects.

OBJECTIVE: The aim of this 6-month prospective randomized clinical study was to compare the effectiveness of autogenous cortical bone (ACB) and bioactive glass (BG) grafting for the regenerative treatment of intraosseous periodontal defects. METHODS: Via a split-mouth design, 15 chronic periodontitis patients (7 men, 8 women; mean age, 43.47 ± 1.45 years) who had probing pocket depths (PPDs) of ⩾6 mm following initial periodontal therapy were randomly assigned to receive 2 treatments in contralateral areas of the dentition: ACB grafting and BG grafting. The parameters compared in the patients were preoperative and 6-month postoperative PPDs, clinical attachment levels (CALs), and radiographic alveolar bone heights. RESULTS: Both treatment modalities resulted in significant changes in postoperative measurements when compared to preoperative values (p < 0.01). PPDs were decreased, CALs were increased, and radiographic alveolar bone heights were increased by 5.00 ± 0.28, 4.60 ± 0.21, and 5.80 ± 0.43 mm in patients treated with ACB grafting and 5.13 ± 0.32, 4.67 ± 0.27, and 5.33 ± 0.36 mm in patients treated with BG grafting, respectively. Differences between the treatments were not statistically significant (P>.05). CONCLUSIONS: Within the limitations of this study, both ACB and BG grafting led to significant improvements in clinical and radiographic parameters 6 months postoperatively. These results suggest that either an ACB graft, which is completely safe with no associated concerns about disease transmission and immunogenic reactions, or a BG graft, which has an unlimited supply, can be selected for regenerative periodontal treatment.

Effects of tacrolimus and nifedipine, alone or in combination, on gingival tissues.

BACKGROUND: The aim of this study is to compare gingival changes induced by short- and long-term tacrolimus and nifedipine administration, alone or in combination, and evaluate the expression levels of tumor suppressor phosphatase and tensin homolog (PTEN) in drug-induced gingival overgrowth. METHODS: Eighty rats were equally divided into eight groups: 1) tacrolimus for 8 weeks; 2) nifedipine for 8 weeks; 3) tacrolimus and nifedipine for 8 weeks; 4) 8-week control; 5) tacrolimus for 24 weeks; 6) nifedipine for 24 weeks; 7) tacrolimus and nifedipine for 24 weeks; and 8) 24-week control. Histomorphometric analyses included measurements of epithelial thickness, connective tissue thickness, and height. Stereologic analyses included measurements of volumetric densities of fibroblasts (Vf), collagen fibers (Vcf), and blood vessels (Vbv). In addition, PTEN expression was analyzed using immunohistochemistry. RESULTS: Epithelial thickness and connective tissue thickness were significantly increased in groups 5, 6, and 7 compared to group 8 (P <0.05), whereas connective tissue height was significantly increased in groups 5 and 7 (P <0.001). Vf and Vcf were significantly increased in group 7 compared to group 8 (P <0.001). PTEN immunoreactivity was significantly decreased in all experimental groups compared to the control groups (P <0.05). CONCLUSIONS: Results suggest that duration of drug administration is a more important risk factor than drug combination. The results include a potentially new insight about PTEN's role in the etiology of drug-induced gingival overgrowth.

Biochemical analysis of pentraxin 3 and fibrinogen levels in experimental periodontitis model.

OBJECTIVE: Pentraxin 3 (PTX3), newly discovered inflammation marker, is a member of acute-phase proteins. The hypothesis, synthesis of gingival tissue and serum PTX-3 increases in the experimental periodontitis model (with 10-day and 40-day periods), was tested by detecting gingival tissue and serum PTX-3 levels in rats with experimental periodontitis. METHODS: Thirty rats were randomly divided into three groups of ten animals each: ligature-induced experimental periodontitis groups (with 10-day (Group1) and 40-day periods (Group2)) and healthy group (Group3). At the end of experimental period, rats were sacrificed, and radiological and histomorphometric analyses were performed on the mandibles. PTX3 levels were measured in gingival tissue and serum samples using ELISA. Plasma fibrinogen levels were measured according to the nephelometric method. RESULTS: Significant alveolar bone resorption and periodontal inflammation were evident in periodontitis groups. Levels of PTX3 in gingival tissue were statistically higher in Group 1 than those in groups 2 and 3 (P < 0.01). No significant difference was found in serum PTX3 levels between experimental periodontitis and control groups (P > 0.05). Plasma fibrinogen levels were significantly increased in the experimental periodontitis groups (P < 0.001). CONCLUSION: PTX3 seems to be associated with tissue destruction in earlier periods of inflammatory periodontal disease, contrary to the fibrinogen findings.

Local peptidergic innervation of gingiva in smoking and non-smoking periodontitis patients.

BACKGROUND: The present study aimed to investigate the local peptidergic innervation of diseased and healthy periodontia in smokers and non-smokers. METHODS: Fifteen smokers and 12 non-smokers, all with localized chronic periodontitis, participated in the study. Periodontally diseased and healthy tooth sites were selected in smokers (groups 1 and 2, respectively) and non-smokers (groups 3 and 4, respectively). Local peptidergic innervation was assessed by the concentrations of two neuropeptides, substance P (SP) and calcitonin gene-related peptide (CGRP), in the gingival biopsies obtained from the groups. Clinical data and biopsies were collected from the same two tooth sites in each group. SP and CGRP levels were measured by enzyme immunosorbent assay in the supernatants of gingival samples. RESULTS: Increased probing depth and attachment loss were found in group 1 compared to group 3 (P<0.05). SP was higher in group 1 compared to groups 2, 3, and 4, and it was higher in group 3 compared to groups 2 and 4 (P<0.05). CGRP was higher in group 1 than in groups 2, 3, and 4, but it was lower in group 3 than in groups 2 and 4 (P<0.05). CONCLUSION: The study results suggested that 1) although smoking may affect the neurogenic inflammation in the presence of periodontitis by increasing local peptidergic innervation, this effect may not be seen in periodontal health, and 2) SP may be regarded as an indicator of periodontitis, whereas CGRP may be important in the acute and/or initial periodontal inflammation.