Objective: To determine the oral health status of patients on maintenance hemodialysis and to identify the factors influencing their oral health. Method and materials: This observational study included 1,186 patients with chronic kidney disease who received maintenance hemodialysis across 33 hospitals in China. The patients were recruited for a questionnaire survey between April and August 2023 at Beijing Chaoyang Hospital using stratified sampling. Data collection tools included the General Information Questionnaire for Maintenance Hemodialysis Patients, the Oral Health Assessment Tool, the Pittsburgh Sleep Quality Index, and the Hospital Anxiety and Depression Scale. Spearman rank correlation coefficients were used to assess the relationships between the oral health of patients on maintenance hemodialysis and continuous variables such as sleep quality and emotional status. Multiple linear regression analysis was employed to explore the relationship between oral health and various variables. Results: The oral health scores of the patients ranged from 8 to 22, with a mean score of 12.54 ± 2.63. The final model of the multiple linear regression analysis indicated a goodness of fit of 22.19%. Independent factors affecting the oral health of patients included smoking, the proportion of medical expenses, water consumption, sleep quality, and anxiety scores (all P .05). High levels of smoking, substantial medical expenses, poor sleep quality, and elevated anxiety scores were risk factors for poor oral health (all P .05). Adequate daily water intake served as a protective factor for oral health (P .05). Conclusion: This study proposes targeted interventions to enhance the management and improvement of oral health in patients on hemodialysis, aiming to provide highly personalized and effective oral health care. These interventions are expected to improve oral health outcomes in future clinical practice. Keywords: influencing factors, maintenance hemodialysis, nursing care, oral health

Summary: Periodontal disease (PD) and Alzheimer’s disease (AD) are inflammatory diseases affecting the adult population of the world. PD is mainly caused by infection with Porphyromonas gingivalis (P. gingivalis) and by the synergistic action of various microorganisms. These microorganisms penetrate into the subgingival tissue and cause bacteremia, leading to disruption of the homeostasis of the internal environment of the body. Virulence factors known as gingipains, which are cysteine proteases and other toxins, including fimbria and lipopolysaccharides (LPS), are strongly associated with periodontitis and other systemic inflammation. PD has a known polymicrobial aetiology, and patients who eventually develop sporadic AD tend to have recurrent infections before a clinical diagnosis of dementia. AD, the most common neurodegenerative disease, is characterised by poor memory and specific hallmark proteins. An increasing number of studies have shown that periodontal pathogens are increasingly associated with this form of dementia. Many articles have shown that P. gingivalis infections directly increase the risk of PD and may indirectly lead to the development of AD. However, these links and probable pathogenesis remain to be explored. The aim of this review was to explore whether P. gingivalis periodontal infection is associated with AD and to provide possible mechanisms of association. Keywords: Alzheimer’s disease, neurodegenerative disease, periodontal disease, Porphyromonas gingivalis (P. gingivalis)

Purpose: Periodontal disease is potentially related to certain kinds of cancer. This review aimed to summarize the relationship between periodontal disease and breast cancer, providing some strategies for the clinical treatment and periodontal health care of breast cancer patients. Materials and Methods: Systematic reviews, randomised controlled trials, prospective and retrospective clinical studies, case series and reports were collected using search terms entered into the PubMed, Google Scholar and JSTOR databases. Results: Research has provided some evidence that periodontal disease is related to the occurrence and development of breast cancer. Periodontal disease and breast cancer have some common pathogenic factors. Periodontal disease may affect the initiation and development of breast cancer involving microorganisms and inflammation. Periodontal health is affected by radiotherapy, chemotherapy, and endocrine therapy for breast cancer. Conclusions: Periodontal therapy for breast cancer patients should be performed differently according to the stage of cancer treatment. Adjuvant endocrine treatment (e.g. bisphosphonates) has a great impact on oral treatment. Periodontal therapy contributes to the primary prevention of breast cancer. Periodontal health care of breast cancer patients is worthy of clinician attention. Keywords: breast cancer, clinical treatment, periodontal disease, periodontal health care

The aim of this retrospective study was to evaluate the effect of free gingival grafts (FGGs) at adjacent mandibular molar implants and to compare the clinical outcomes between the first molar (M1) and second molar (M2) sites. Twenty-one patients with 44 implants were included. At the 3-year follow-up, the mean increase in the keratinized mucosa width (KMW) was 2.35 ± 1.33 mm, and the mean KMW shrinkage rate was 58% ± 23%. M1 sites showed a significantly greater increase of KMW and less graft shrinkage than M2 sites (M1: 2.87 ± 1.40 mm and 49% ± 24%, M2: 1.83 ± 1.06 mm and 66% ± 19%, P < .05). The results show that using FGG to increase KMW in mandibular molar implants was a predictable treatment method, and M1 sites were associated with a greater KMW increase than M2 sites.

Purpose: To evaluate the biaxial flexural strength of different porcelain-to-zirconia thickness ratios and bonding strategies of a stress-free bilayer CAD/CAM ceramic system. Materials and methods: A total of 60 zirconia discs (diameter: 15 mm; thickness: 0.3 or 0.5 mm; n = 30 for each thickness) were divided into six groups (n = 10 each) according to porcelain-to-zirconia ratio and bonding strategy: VM/Zr (control): zirconia discs veneered with a feldspathic ceramic (VM 9, Vita) in 0.9-mm and 0.7-mm thicknesses using a conventional hand-layering technique; VB/Zr-SBU: zirconia discs airborne particle-abraded with 50-μm Al2O3 particles followed by an MDP primer application (Single Bond Universal, 3M) and bonded to the porcelain with a resin cement (Panavia F 2.0, Kuraray); and VB/Zr-RC: zirconia discs airborne particle-abraded with 30-μm silica-coated Al2O3 particles and silanized and bonded to the porcelain with the same resin cement. Before cementation, the VB (Vitablocs II) discs were etched with 5% hydrofluoric acid (60 seconds), followed by silane application. The bilayers (thickness = 1.2 mm) were loaded with 750 g while light curing the resin cement. Two porcelain-to-zirconia thickness ratios were evaluated: 0.9: 0.3 mm and 0.7: 0.5 mm. All groups were subjected to 106 mechanical cycles, followed by a biaxial flexural test. Data (MPa) were subjected to two-way analysis of variance (ANOVA), Tukey test (5%), and Weibull analyses. Results: Two-way ANOVA revealed that the factor porcelain-to-zirconia ratio (P = .0556) was not significant; however, the bonding strategy factor was statistically significant. Among the 0.5-mm zirconia groups, the VB/Zr-SBU group presented higher flexural strength (s) than the VM/Zr or VB/Zr-RC groups. Similar results were also found for the 0.3-mm zirconia groups, in which the VB/Zr-SBU group also presented higher strength than the others, which were similar in comparison (Tukey). The Weibull modulus was similar among the groups; however, the characteristic strength was significantly different (P = .000). Conclusion: The zirconia bonding strategy with 50-μm Al2O3 airborne-particle abrasion, followed by a primer application, increases the flexural strength of a stress-free bilayer CAD/CAM ceramic system.

Purpose: The aim of the present systematic review with meta-analysis was to investigate the clinical effectiveness of EMD (enamel matrix derivative) using a minimally invasive surgical technique (MIST) or flapless approach for the treatment of severe periodontal probing depths. Materials and Methods: A systematic review of the literature including searches in PubMed/Medline, Cochrane Library, Google Scholar, and Grey Literature databases as well as manual searches was performed on September 1st, 2021. Studies utilising EMD in a non-surgical or minimally invasive approach were included. The eligibility criteria comprised randomised controlled trials (RCTs) comparing minimally-invasive/flapless approaches with/without EMD for the treatment of probing depths >5 mm. Results: From 1525 initial articles, 7 RCTs were included and 12 case series discussed. Three studies investigated a MIST approach, whereas 3 studies utilised a flapless approach. One study compared EMD with either a MIST or a flapless approach. The RCTs included ranged from 19–49 patients with at least 6 months of follow-up. While 5 of the studies included smokers, patients smoking >20 cigarettes/day were excluded from the study. The meta-analysis revealed that EMD with MIST improved recession coverage (REC) and bone fill (BF) when compared to MIST without EMD. However, no difference in CAL or PD was observed between MIST + EMD vs MIST without EMD. No statistically significant advantage was found for employing the EMD via the flapless approach. Conclusions: Implementing EMD in MIST procedures displayed statistically significant improvement in REC and BF when compared to MIST alone. These findings suggest that MIST in combination with EMD led to improved clinical outcomes while EMD employed in nonsurgical flapless therapy yielded no clinical benefits when compared to nonsurgical therapy alone without EMD. More research is needed to substantiate these findings. Keywords: EMD, enamel matrix derivative, enamel matrix proteins, intrabony defect, minimally invasive surgery

Purpose: To investigate the effect of platelet-rich fibrin on bone formation by investigating its use in guided bone regeneration, sinus elevation and implant therapy. Materials and methods: This systematic review and meta-analysis were conducted and reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The eligibility criteria comprised human controlled clinical trials comparing the clinical outcomes of platelet-rich fibrin with those of other treatment modalities. The outcomes measured included percentage of new bone formation, percentage of residual bone graft, implant survival rate, change in bone dimension (horizontal and vertical), and implant stability quotient values. Results: From 320 articles identified, 18 studies were included. Owing to the heterogeneity of the investigated parameters, a meta-analysis was only possible for sinus elevation. There is a general lack of data from comparative randomised clinical trials evaluating platelet-rich fibrin for guided bone regeneration procedures (only two studies), with no quantifiable advantages in terms of new bone formation or dimensional bone gain found in the platelet-rich fibrin group. For sinus elevation, the meta-analysis demonstrated no advantage in terms of histological new bone formation in the control group (bone graft alone) compared with the test group (bone graft and platelet-rich fibrin). Two studies demonstrated that platelet-rich fibrin may shorten healing periods prior to implant placement. Platelet-rich fibrin was also shown to slightly enhance primary implant stability (implant stability quotient value < 5) as assessed using implant stability quotients and resonance frequency analysis parameters, with no histological data evaluating bone–implant contact yet available on this topic. In one study, platelet-rich fibrin was shown to improve the clinical parameters when utilised as an adjunct for the treatment of peri-implantitis. Conclusions: In the majority of studies, platelet-rich fibrin offered little or no clear advantage in terms of new bone formation as evaluated in various studies on guided bone regeneration and sinus elevation, nor in implant stability and treatment of peri-implantitis. Various authors and systematic reviews on the topic have now expressed criticism of the various study designs and protocols, and the lack of appropriate controls and available information regarding patient selection. Well-controlled human studies on these specific topics are required. Conflict-of-interest statement: Richard J Miron holds intellectual property on platelet-rich fibrin. All other authors declare no conflicts of interest. Keywords: biomaterials, bone graft, growth factors, platelet-rich fibrin, platelet concentrates

Purpose: To investigate the use of platelet-rich fibrin for alveolar ridge preservation compared to natural healing, bone graft material and platelet-rich fibrin in combination with bone graft material. Materials and methods: The present systematic review was conducted and reported according to the Preferred Reporting Items for Systematic Reviews and Meta-analysis guidelines. The review examined randomised controlled trials comparing the clinical outcomes of platelet-rich fibrin with those of other modalities for alveolar ridge preservation. Studies of third molar extraction site healing were excluded. The studies were classified into three categories: natural wound healing vs platelet-rich fibrin; bone graft material vs platelet-rich fibrin; and bone graft material vs bone graft material and platelet-rich fibrin. Results: From 179 articles identified, 16 randomised controlled trials were included. Owing to the heterogeneity of the investigated parameters, it was not possible to perform a meta-analysis. In total, 10 randomised controlled trials compared platelet-rich fibrin to natural wound healing, with seven of these demonstrating favourable outcomes to either limit postextraction dimensional changes or improve new bone formation in the platelet-rich fibrin group. Three of four studies comparing healing with bone graft material to platelet-rich fibrin found that the latter led to significantly greater horizontal or vertical bone resorption, and the bone graft material was more able to maintain the ridge dimensions. Two out of three randomised controlled trials investigating healing with both bone graft material and platelet-rich fibrin reported better outcomes using this combined approach than with bone graft material alone. All studies investigating soft tissue healing with platelet-rich fibrin demonstrated better outcomes in the platelet-rich fibrin group. Conclusions: The majority of studies comparing healing with platelet-rich fibrin to natural healing concluded that the former more successfully limits postextraction dimensional changes than the latter. However, 75% of studies investigating platelet-rich fibrin vs bone graft material reported better results in the bone graft group with respect to its ability to maintain postextraction dimensional changes. The addition of platelet-rich fibrin to bone graft material may improve clinical outcomes, although data are limited. Keywords: advanced platelet-rich fibrin, alveolar ridge preservation, biomaterials, extraction site management, growth factors, leucocyte- and platelet-rich fibrin, platelet concentrates, platelet-rich fibrin, systematic review Conflict-of-interest statement: Richard J Miron holds intellectual property on platelet-rich fibrin. All other authors declare no conflicts of interest related to this study.