Further evidence that periodontal bone loss increases with smoking and age

Effect of recreational cannabis use on bone mineral density: a systematic review

The recreational use of cannabis products has risen considerably worldwide over the past decade. As the cannabis legal market grows, a critical challenge has been to make substantiated claims about the benefits and adverse health problems triggered by cannabis exposure. Despite accumulating evidence from animal studies demonstrating the role of cannabinoids on bone metabolism, there are conflicting results in clinical literature regarding their effects on bone health outcomes.We undertook a systematic review to assess the evidence for the safety of cannabis use on bone health. We searched the databases MEDLINE, EMBASE, Cochrane Library, and Web of Science up to March 2023 for studies evaluating the effect of the recreational use of cannabis on the bone mineral density (BMD) of adults.Among the 2620 studies reviewed, three cross-sectional studies and one randomized controlled trial comprised 4032 participants from 18 to 60 years who met the inclusion criteria. Two studies showed that cannabis exposure decreased BMD, while the other 2 indicated no alteration. Despite the different study designs, the included studies showed a low risk of bias according to the Joanna Briggs Institute tool.Eligible studies present differences in cannabis products, administration routes, and exposure determination. Further longitudinal research is needed to establish multiple clinical predictors associated with potentially negative consequences of cannabis exposure, especially in vulnerable populations such as elderly individuals.

The transcriptomic response to cannabidiol of Treponema denticola, a phytocannabinoid-resistant periodontal pathogen

AIM

The use of cannabis, which contains multiple antimicrobials, may be a risk factor for periodontitis. We hypothesized that multiple oral spirochetes would be phytocannabinoid-resistant and that cannabidiol (CBD) would act as an environmental stressor to which Treponema denticola would respond transcriptionally, thereby providing first insights into spirochetal survival strategies.

MATERIALS AND METHODS

Oral spirochete growth was monitored spectrophotometrically in the presence and absence of physiologically relevant phytocannabinoid doses, the transcriptional response to phytocannabinoid exposure determined by RNAseq, specific gene activity fluxes verified using qRT-PCR and orthologues among fully sequenced oral spirochetes identified.

RESULTS

Multiple strains of oral treponemes were resistant to CBD (0.1-10 μg/mL), while T. denticola ATCC 35405 was resistant to all phytocannabinoids tested (CBD, cannabinol [CBN], tetrahydrocannabinol [THC]). A total of 392 T. denticola ATCC 35405 genes were found to be CBD-responsive by RNAseq. A selected subset of these genes was independently verified by qRT-PCR. Genes found to be differentially activated by both methods included several involved in transcriptional regulation and toxin control. Suppressed genes included several involved in chemotaxis and proteolysis.

CONCLUSIONS

Oral spirochetes, unlike some other periodontal bacteria, are resistant to physiological doses of phytocannabinoids. Investigation of CBD-induced transcriptomic changes provided insight into the resistance mechanisms of this important periodontal pathogen. These findings should be considered in the context of the reported enhanced susceptibility to periodontitis in cannabis users.

Potential Mechanisms Underlying Marijuana-Associated Periodontal Tissue Destruction

While definitive evidence awaits, cannabis is emerging as a likely risk factor for periodontal tissue destruction. The mechanisms that underlie potential cannabis-induced or cannabis-enhanced periodontal diseases, however, remain to be elucidated. Herein, we 1) examine insights obtained from the endocannabinoid system, 2) summarize animal models of exposure to cannabinoid receptor agonists and antagonists, 3) review the evidence suggesting that cannabis and cannabis-derived molecules exert a profound influence on components of the oral microbiome, and 4) assess studies indicating that marijuana and phytocannabinoids compromise the immune response to plaque. Furthermore, we address how knowledge of cannabinoid influences in the oral cavity may be exploited to provide potential novel periodontal therapeutics, while recognizing that such medicinal approaches may be most appropriate for nonhabitual marijuana users. The suspected increase in susceptibility to periodontitis in marijuana users is multifaceted, and it is clear that we are only beginning to understand the complex toxicological, cellular, and microbial interactions involved. With marijuana consumption increasing across all societal demographics, periodontal complications of use may represent a significant, growing oral health concern. In preparation, an enhanced research response would seem appropriate.

Oral Health Implications of Risky Behaviors in Adolescence

Adolescence is a time for new discoveries, which may lead teens to engage in impulsive behaviors. Although social media and the Internet have brought great benefits to the world, they can also have a negative influence on adolescents, facilitating their engagement in risky behaviors. Positive parenting and healthy friendships in adolescence have a protective effect against sensation-seeking behaviors. Dental practitioners also have a significant role in steering young patients toward healthy behaviors. They play an essential role in the early recognition, initiation of appropriate interventions, and referrals for treatment of youth at risk.

Moderate and severe periodontitis are positively associated with metabolic syndrome

OBJECTIVE

This study investigated the association between periodontitis severity (exposure) and metabolic syndrome (MetS - outcome), using two criteria for diagnosis of the outcome, since this relationship remains unexplored.

MATERIALS AND METHODS

A case-control study was conducted with 870 individuals: 408 with first MetS diagnosis (cases) and 462 without MetS (controls). Participants' general information was obtained using a questionnaire and laboratory data was collected from medical records. Periodontitis severity criteria followed the Center for Disease Control and Prevention: none, mild, moderate, and severe. Odds ratios (OR) and 95% confidence intervals (95% CI) were determined by logistic regression analysis.

RESULTS

Findings showed a positive association between moderate and severe periodontitis and MetS: OR_adjusted = 1.64 (95% CI: 1.01 to 2.68) and OR_adjusted = 1.94 (95% CI: 1.19 to 3.16), respectively, after adjustment for age, sex, schooling level, smoking habit, and cardiovascular disease. The adjusted measurements showed that among individuals with moderate or severe periodontitis, the probability of having MetS was around two times greater than among those without periodontitis, and that the chance was greater among participants with severe periodontitis than those with moderate periodontitis.

CONCLUSION

An association between the severity of periodontal status and MetS was found, suggesting a possible relationship between the two diseases.

CLINICAL RELEVANCE

MetS influences the etiology of cardiovascular diseases, one of the leading causes of mortality worldwide. The findings suggest that the greater the severity of periodontitis, the greater is the association magnitude with MetS. The health professional needs to recognize that the importance of periodontal disease may play in MetS.

Inflammation has synergistic effect with nicotine in periodontitis by up-regulating the expression of α7 nAChR via phosphorylated GSK-3β

Periodontitis is the leading cause of adult tooth loss, and those who smoke are at an increased risk of developing periodontitis. α7 nicotinic acetylcholine receptor (α7 nAChR) is proposed to mediate the potential synergistic effect of nicotine and inflammation in smoking‐related periodontitis. However, this has not been experimentally demonstrated. We isolated and cultured human periodontal ligament stem cells (PDLSCs) from healthy and inflamed tissues. PDLSCs were treated with either inflammatory factors or nicotine. We measured expression of genes that are associated with osteogenic differentiation and osteoclast formation using RT‐qPCR and Western blot analyses. Besides, immunohistochemical staining, micro‐CT analysis and tartaric acid phosphatase staining were used to measure α7 nAChR expression and function. Inflammation up‐regulated α7 nAChR expression in both periodontal ligament tissues and PDLSCs. The up‐regulated α7 nAChR contributed to the synergistic effect of nicotine and inflammation, leading to a decreased capability of osteogenic differentiation and increased capability of osteoclast formation‐induction of PDLSCs. Moreover, the inflammation‐induced up‐regulation of α7 nAChR was partially dependent on the level of phosphorylated GSK‐3β. This study provides experimental evidence for the pathological development of smoking‐related periodontitis and sheds new light on developing inflammation and α7 nAChR‐targeted therapeutics to treat and prevent the disease.

Marijuana-Derived Cannabinoids Trigger a CB2/PI3K Axis of Suppression of the Innate Response to Oral Pathogens

Cannabis use is an emergent risk factor for periodontitis, a chronic bacterial-induced disease of the supporting structures of the teeth. However, the mechanisms by which marijuana exposure predisposes to periodontal tissue destruction have yet to be elucidated. Therefore, we examined the influence of physiologically relevant doses of major marijuana-derived phytocannabinoid subtypes (cannabidiol [CBD]; cannabinol [CBN]; and tetrahydrocannabinol [THC], 1.0 μg/ml) on the interactions of three ultrastructurally variant oral pathogens, Porphyromonas gingivalis, Filifactor alocis, and Treponema denticola with the immune system. CBD, CBN, and THC each suppressed P. gingivalis-induced IL-12 p40, IL-6, IL-8, and TNF release while enhancing the anti-inflammatory cytokine, IL-10, from human innate cells. Similar phenomena were observed in F. alocis- and T. denticola-exposed human monocytes and human gingival keratinocytes. Higher phytocannabinoid doses (≥5.0 μg/ml) compromised innate cell viability and inhibited the growth of P. gingivalis and F. alocis, relative to unexposed bacteria. T. denticola, however, was resistant to all cannabinoid doses tested (up to 10.0 μg/ml). Pharmaceutical inhibition and efficient gene silencing indicated that a common CB2/PI3K axis of immune suppression is triggered by phytocannabinoids in vitro. This pathway does not appear to perpetuate through the canonical GSK3β-dependent cholinergic anti-inflammatory pathway, the predominant endogenous inflammatory control system. In a repetitive, transient oral infection model, CBD also suppressed P. gingivalis-induced innate immune markers in wild-type mice, but not in CB2^−/− mice. If such phenomena occur in humans in situ, environmental cannabinoids may enhance periodontitis via direct toxic effects on specific oral bacteria; by compromising innate cell vitality; and/or through a suppressed innate response to periodontal pathogens involving a CB2/PI3K signaling lineage.

Success of non-surgical periodontal therapy in adult periodontitis patients: A retrospective analysis

Objective

To evaluate the results of active non‐surgical treatment in patients diagnosed with adult periodontitis treated in a specialized clinic for periodontology.

Material & Methods

In total, 1182 patients with adult periodontitis received active non‐surgical therapy, which involved professional oral hygiene instruction, scaling and root planing, supragingival polishing and elective systemic antimicrobial medication. The results of this therapy were based on a full‐mouth periodontal chart as assessed at the time of evaluation. Successful treatment as periodontal pocket depth (PPD) ≤5 mm was the main outcome parameter with bleeding on pocket probing as secondary outcome. Patient‐related factors such as smoking and severity of periodontitis at baseline and site‐related factors such as tooth type, furcation involvement and endodontic treatment were analysed. Possible relations with assessed parameters and the success of active periodontal therapy were evaluated.

Results

Overall 39% of the patients reached the successful treatment objective and a mean bleeding on pocket probing tendency of 14%. Treatment success appeared to be dependent on tooth type where the results at single‐rooted front teeth (85%) and premolar teeth (78%) were more successful than at molar teeth (47%). Analysis revealed that in 55% of the cases furcation involvement at molars was associated with the absence of success. Endodontic treatment was associated with absence of success in 8%‐11% of the cases. Smoking negatively influences successful treatment outcome (P < 0.001).

Conclusion

Active non‐surgical periodontal therapy in patients with adult periodontitis resulted in approximately one third of the cases in the success endpoint of PPD ≤ 5mm. Sub‐analysis showed that the outcome appeared to be dependent on tooth type, furcation involvement, severity of periodontal disease at intake and smoking status.

[The effect of Toll-like receptor 4 in nicotine suppressing the osteogenic potential of periodontal ligament stem cells]

Objective To explore the impact of nicotine on proliferation and osteogenic capability of periodontal ligament stem cells (PDLSCs), and the role of Toll-like receptor 4 (TLR4) in nicotine, suppressing the osteogenic capability of PDLSCs. Methods PDLSCs were cultured in vitro, and the flow cytometer was used to identify the surface antigen markers of PDLSCs. WST-1 was used to detect the proliferation ability of PDLSCs, which were stimulated by different concentrations of nicotine. Alizarin red staining was used to observe the formation of mineralized nodules after PDLSCs stimulation with different concentrations of nicotine. Real-time polymerase chain reaction (RT-PCR) and Western blot were used to detect the change in osteogenic potential of PDLSCs stimulated by nicotine, after TAK-242, and with the inhibitor of TLR4. Results PDLSCs expressed mesenchymal stem cell-associated markers CD90 and CD105. When the concentration of nicotine was 10⁻⁴ mol·L⁻¹, the PDLSC proliferation could be suppressed after 3 d compared with the control group (P<0.05). The amount of mineralized nodules reduced after osteogenic differentiation at 21 d by alizarin red staining. RT-PCR and Western blot showed the expression levels of alkaline phosphatase (ALP), and osteocalcin (OCN), and the Runt-related transcription factor-2 (Runx-2) were lower than in the control group when nicotine suppressed the PDLSCs (P<0.05). This effect was attenuated after TAK-242 was added. Conclusion Nicotine suppresses the proliferation and osteogenic capability of PDLSCs, which may be regulated by TLR4.

General Practitioners and Dentists: A Call for Action Against Tobacco

INTRODUCTION

To investigate the frequency of advice to quit smoking received by the Italian population from general practitioners (GP) and dentists, we analyzed a cross-sectional study.

METHODS

A face-to-face survey was conducted in 2014 on 3052 individuals, representative of the general Italian population aged 15 years or more.

RESULTS

During the previous year, 89% of individuals (82% of smokers) reported that they had visited a GP while 71% (67% of smokers) had visited a dentist. Among smokers, 25% reported that they had received advice to quit smoking from their GP, and 26% from their dentist. Advice by GPs was less frequently received by smokers with higher education (multivariate odds ratios (OR) were 0.48 for intermediate and 0.38 for high as compared to low education), and more frequently by heavy smokers (≥15 cigarettes/day; OR = 1.78), those with intention to quit (OR = 2.59), with previous quit attempts (OR = 2.09), and those aware of the existence of smoking cessation services (OR = 1.59). Advice by dentists was more frequently received by smokers aged 25-44 years (OR = 3.55 compared to those aged 15-24) and those with an intention to quit (OR = 2.46). Among Italian current smokers, 32% reported that their GP and 17% that their dentist was a current smoker. The corresponding figures among young smokers were 40% and 26%, respectively.

CONCLUSION

Healthcare providers have the potential to become a key reference point in the fight against smoking. However, before acting, GPs and dentists should set a good example: those who smoke should urgently quit or at least refrain from smoking during working hours.

IMPLICATIONS

GPs and dentists, reaching the large majority of Italian smokers, can make a major contribution in the fight against tobacco. Future studies are needed to investigate possible reasons of the apparently high smoking prevalence among GPs, in order to develop tailored smoking cessation interventions for healthcare providers.