The Effect of Different Electric Toothbrush Technologies on Interdental Plaque Removal: A Systematic Review with a Meta-Analysis.

The removal of dental plaque from the gingival margins of the teeth is essential to maintaining periodontal health. Whilst it has been established that electric toothbrushes demonstrate a greater ability to remove plaque, no systematic review has specifically investigated which technology is better for removing plaque from the interdental tooth surfaces, where plaque control may be more difficult. Three databases were searched until October 2023: MEDLINE and DOSSS via EBSCOhost and Embase. Data extraction was carried out on studies which met the inclusion criteria, and a risk of bias assessment was completed. The study findings were combined via a narrative synthesis and a meta-analysis where appropriate. A total of 77 studies were found, out of which 14 were selected and included in the analysis. The mean difference in interproximal plaque reduction, measured using the Rustogi Modified Naval Plaque Index (RMNPI) at 8 weeks, was 0.09 (p < 0.00001) in favor of the oscillating-rotating toothbrush. At 6 and 12 weeks, the mean difference in plaque reduction (RMNPI) was 0.05 (p = 0.0008) and 0.04 (p = 0.0001) in favor of the oscillating-rotating toothbrush, respectively. The studies show a tendency for oscillating-rotating toothbrushes to remove more interproximal plaque than oscillating toothbrushes, especially in a short time (8 weeks).

Treponema denticola Has the Potential to Cause Neurodegeneration in the Midbrain via the Periodontal Route of Infection-Narrative Review.

Alzheimer's disease (AD) is a neurodegenerative disease and the most common example of dementia. The neuropathological features of AD are the abnormal deposition of extracellular amyloid-ß (Aß) and intraneuronal neurofibrillary tangles with hyperphosphorylated tau protein. It is recognized that AD starts in the frontal cerebral cortex, and then it progresses to the entorhinal cortex, the hippocampus, and the rest of the brain. However, some studies on animals suggest that AD could also progress in the reverse order starting from the midbrain and then spreading to the frontal cortex. Spirochetes are neurotrophic: From a peripheral route of infection, they can reach the brain via the midbrain. Their direct and indirect effect via the interaction of their virulence factors and the microglia potentially leads to the host peripheral nerve, the midbrain (especially the locus coeruleus), and cortical damage. On this basis, this review aims to discuss the hypothesis of the ability of Treponema denticola to damage the peripheral axons in the periodontal ligament, to evade the complemental pathway and microglial immune response, to determine the cytoskeletal impairment and therefore causing the axonal transport disruption, an altered mitochondrial migration and the consequent neuronal apoptosis. Further insights about the central neurodegeneration mechanism and Treponema denticola's resistance to the immune response when aggregated in biofilm and its quorum sensing are suggested as a pathogenetic model for the advanced stages of AD.

Locus Coeruleus Dysfunction and Trigeminal Mesencephalic Nucleus Degeneration: A Cue for Periodontal Infection Mediated Damage in Alzheimer's Disease?

Alzheimer's disease (AD) is a leading neurodegenerative disease with deteriorating cognition as its main clinical sign. In addition to the clinical history, it is characterized by the presence of two neuropathological hallmark lesions; amyloid-beta (Aß) and neurofibrillary tangles (NFTs), identified in the brain at post-mortem in specific anatomical areas. Recently, it was discovered that NFTs occur initially in the subcortical nuclei, such as the locus coeruleus in the pons, and are said to spread from there to the cerebral cortices and the hippocampus. This contrasts with the prior acceptance of their neuropathology in the enthorinal cortex and the hippocampus. The Braak staging system places the accumulation of phosphorylated tau (p-tau) binding to NFTs in the locus coeruleus and other subcortical nuclei to precede stages I-IV. The locus coeruleus plays diverse psychological and physiological roles within the human body including rapid eye movement sleep disorder, schizophrenia, anxiety, and depression, regulation of sleep-wake cycles, attention, memory, mood, and behavior, which correlates with AD clinical behavior. In addition, the locus coeruleus regulates cardiovascular, respiratory, and gastrointestinal activities, which have only recently been associated with AD by modern day research enabling the wider understanding of AD development via comorbidities and microbial dysbiosis. The focus of this narrative review is to explore the modes of neurodegeneration taking place in the locus coeruleus during the natural aging process of the trigeminal nerve connections from the teeth and microbial dysbiosis, and to postulate a pathogenetic mechanism due to periodontal damage and/or infection focused on Treponema denticola.

The Mechanistic Pathways of Periodontal Pathogens Entering the Brain: The Potential Role of Treponema denticola in Tracing Alzheimer's Disease Pathology.

Alzheimer's Disease (AD) is a complex neurodegenerative disease and remains the most common form of dementia. The pathological features include amyloid (Aß) accumulation, neurofibrillary tangles (NFTs), neural and synaptic loss, microglial cell activation, and an increased blood-brain barrier permeability. One longstanding hypothesis suggests that a microbial etiology is key to AD initiation. Among the various periodontal microorganisms, Porphyromonas gingivalis has been considered the keystone agent to potentially correlate with AD, due to its influence on systemic inflammation. P. gingivalis together with Treponema denticola and Tannerella forsythia belong to the red complex consortium of bacteria advocated to sustain periodontitis within a local dysbiosis and a host response alteration. Since the implication of P. gingivalis in the pathogenesis of AD, evidence has emerged of T. denticola clusters in some AD brain tissue sections. This narrative review explored the potential mode of spirochetes entry into the AD brain for tracing pathology. Spirochetes are slow-growing bacteria, which can hide within ganglia for many years. It is this feature in combination with the ability of these bacteria to evade the hosts' immune responses that may account for a long lag phase between infection and plausible AD disease symptoms. As the locus coeruleus has direct connection between the trigeminal nuclei to periodontal free nerve endings and proprioceptors with the central nervous system, it is plausible that they could initiate AD pathology from this anatomical region.

Critical features of periodontal flaps with regard to blood clot stability: A review.

BACKGROUND: Wound healing is a multifactorial procedure involving different cell types and biological mediators. The principles of wound healing are also applicable to periodontal tissues. The formation and stability of blood clots play a vital role in successful healing of wounds in periodontal tissues. The aim of the present review was to highlight the vital factors of periodontal flaps associated with blood clot stability. HIGHLIGHT: The data on periodontal regeneration and wound healing have evolved greatly in light of several factors, including space for blood clots and blood clot stabilization. In periodontal osseous defects, the stability of blood clots seems critical to wound healing. If mechanical forces can be managed by wound stabilization, the gingival flap-tooth root interface may show connective tissue repair. However, compromised adhesion is susceptible to mechanical forces and can cause wound breakage and epithelialization. CONCLUSION: The presence of a thick blood clot may hinder the plasmatic circulation between the recipient bed and graft during the initial stage of healing, which is critical in cases of mucogingival surgery. Root conditioning can also determine the healing consequence by enhancing blood clot adhesion.

Long-term Clinical Performance of Regeneration versus Conservative Surgery in the Treatment of Infra-bony Defects:A systematic review.

AIMS: To determine the differences in the long-term clinical outcomes between Regeneration (REG) and Conservative Surgery (CS) in infra-bony defects. MATERIALS AND METHODS: Three databases were searched [PubMed, Medline and Embase] up to April 2019. Following screening, 17 studies were included. Randomized Controlled Clinical Trials, Controlled Clinical Trials and retrospective studies with long-term clinical observations (≥ 24-months) were selected. After subgrouping the studies regarding the grafting material and the used flap, meta-analysis was performed for different outcomes [clinical attachment level gain (CALGain), probing pocket depth reduction (PPDRed), recession increase (RECInc) and bone fill (BF)] at different follow-ups (24-, 36-, 48- to 60- and 120- to 240-months). RESULTS: The time-related meta-analysis favoured REG at every interval for every outcome. In subgroup analysis, enamel matrix derivative (EMD) performed significantly better for both CALGain [24- (p less than 0.0001), 36- (p=0.02) and 60-months (p less than 0.00001)] and PPDRed [24- (p=0.0004), 36- (p=0.003) and 60-months (p less than 0.00001)]. For Ceramic Grafts (CGs), CALGain at 48-months (p less than 0.00001) and PPDRed at 24- (p=0.0006), 36- (p less than 0.00001) and 48-months (p less than 0.00001) follow-up showed better results. CONCLUSION: The better outcomes from REG using EMD or CGs can be maintained for a longer duration, suggesting a potential longevity of the occurred healing.

Adjunctive Platelet-Rich Plasma (PRP) in Infrabony Regenerative Treatment: A Systematic Review and RCT's Meta-Analysis.

BACKGROUND AND OBJECTIVE: The purpose of this study was to highlight the clinical performance of platelet-rich plasma (PRP) used as an adjunctive tool for regeneration in infrabony periodontal defects using different biomaterials or performing different surgical flap approaches. Comparative evaluation of main clinical outcomes as probing pocket depth reduction, clinical attachment gain, and recession reduction with and without the use of PRP has been analysed. MATERIALS AND METHODS: According to the focused question, an electronic and hand searching has been performed up to December 2016. From a batch of 73 articles, the selection strategy and Jadad quality assessment led us to include 15 studies for the meta-analysis. RESULTS: Despite the high heterogeneity found and the lack of complete data regarding the selected clinical outcomes, a comparative analysis has been possible by the categorization of used biomaterials and surgical flap approaches. This method led us to observe the best performance of grafts with the use of adjunctive PRP in CAL gain and PPD reduction. No difference has been outlined with a specific surgical flap. CONCLUSIONS: Although PRP is considered a cheap and patient's derived growth factor, the not conclusive data reported would suggest that its use in addition to bone substitutes could be of some clinical benefit in the regenerative treatment of infrabony defects. CLINICAL RELEVANCE: This systematic review was intended to sort out the huge controversial debate in the field about the possible use of PRP in regenerative surgery in infrabony defect. The clinical relevance of using blood-borne growth factors to conventional procedures is effective as these could determine a better performance and outcomes despite the surgical approach adopted and limit the use of additional biomaterials for the blood clot stabilization.

Transmission of the 263K scrapie strain by the dental route.

Apart from a few cases of iatrogenic and familial human transmissible spongiform encephalopathies (TSEs) or prion diseases, the cause of Creutzfeldt-Jakob disease (CJD) remains unknown. In this paper we investigated the possibility that dental procedures may represent a potential route of infection. This was assessed by using the experimental model of scrapie in hamster. In the first part of this study we found that after intraperitoneal inoculation, oral tissues commonly involved in dental procedures (gingival and pulp tissues) bore a substantial level of infectivity. We also found high scrapie infectivity in the trigeminal ganglia, suggesting that the scrapie agent had reached the oral tissues through the sensitive terminal endings of the trigeminal nerves. In the second part of the study we inoculated a group of hamsters in the tooth pulp and showed that all of them developed scrapie disease. In these animals, we detected both infectivity and the pathological prion protein (PrPsc) in the trigeminal ganglion homolateral to the site of injection but not in the controlateral one. This finding suggests that the scrapie agent, and likely other TSE agents as well, spreads from the buccal tissues to the central nervous system through trigeminal nerves. Although these findings may not apply to humans affected by TSEs, they do raise concerns about the possible risk of transmitting these disorders through dental procedures. Particular consideration should be taken in regard to new variant CJD patients because they may harbour more infectivity in peripheral tissues than sporadic CJD patients.