Efficacy of a novel three-step decontamination protocol for titanium-based dental implants: An in vitro and in vivo study.

AIM: The aim of the study was to evaluate several mechanical and chemical decontamination methods associated with a newly introduced biofilm matrix disruption strategy for biofilm cleaning and preservation of implant surface features. MATERIALS AND METHODS: Titanium (Ti) discs were obtained by additive manufacturing. Polymicrobial biofilm-covered Ti disc surfaces were decontaminated with mechanical [Ti curette, Teflon curette, Ti brush, water-air jet device, and Er:YAG laser] or chemical [iodopovidone (PVPI) 0.2% to disrupt the extracellular matrix, along with amoxicillin; minocycline; tetracycline; H2 O2 3%; chlorhexidine 0.2%; NaOCl 0.95%; hydrocarbon-oxo-borate-based antiseptic] protocols. The optimal in vitro mechanical/chemical protocol was then tested in combination using an in vivo biofilm model with intra-oral devices. RESULTS: Er:YAG laser treatment displayed optimum surface cleaning by biofilm removal with minimal deleterious damage to the surface, smaller Ti release, good corrosion stability, and improved fibroblast readhesion. NaOCl 0.95% was the most promising agent to reduce in vitro and in vivo biofilms and was even more effective when associated with PVPI 0.2% as a pre-treatment to disrupt the biofilm matrix. The combination of Er:YAG laser followed by PVPI 0.2% plus NaOCl 0.95% promoted efficient decontamination of rough Ti surfaces by disrupting the biofilm matrix and killing remnants of in vivo biofilms formed in the mouth (the only protocol to lead to ~99% biofilm eradication). CONCLUSION: Er:YAG laser + PVPI 0.2% + NaOCl 0.95% can be a reliable decontamination protocol for Ti surfaces, eliminating microbial biofilms without damaging the implant surface.

Evaluation of the Microbial Profile on the Polydioxanone Membrane and the Collagen Membrane Exposed to Multi-Species Subgingival Biofilm: An In Vitro Study.

Dehiscence in surgeries involving membranes often leads to bacterial contamination, hindering the healing process. This study assessed bacterial colonization on various membrane materials. Polydioxanone (PDO) membranes, with thicknesses of 0.5 mm and 1 mm, and a collagen membrane were examined. Packages containing polystyrene pins were crafted using these membranes, attached to 24-well plates, and exposed to oral bacteria from supra and subgingival biofilm. After a week's anaerobic incubation, biofilm formation was evaluated using the DNA-DNA hybridization test. Statistical analysis employed the Kruskal-Wallis test with Dunn's post hoc test. The biofilm on the polystyrene pins covered by the 0.5 mm PDO membrane showed a higher count of certain pathogens. The collagen membrane had a greater total biofilm count on its inner surface compared to both PDO membranes. The external collagen membrane face had a higher total biofilm count than the 0.5 mm PDO membrane. Furthermore, the 1 mm PDO membrane exhibited a greater count of specific pathogens than its 0.5 mm counterpart. In conclusion, the collagen membrane presented more biofilm and pathogens both internally and on its inner surface.

Is there an effective way to control pain perception after free gingival graft removal? A systematic review and meta-analysis.

The literature describes multiple ways to stimulate wound healing to reduce the patient's perception of pain. This systematic review aimed to evaluate if methods that enhance wound healing can reduce the patient's perception of pain after free gingival graft removal from the palate region compared to natural healing. A systematic review protocol was written following the PRISMA checklist. Electronic searches of five databases were performed to identify randomized clinical trials (RCTs) that assessed the patient's perception of pain after the removal of a free gingival graft from the palate. The primary outcome was the visual analog scale (VAS) score assessing the patient's perception of pain 7 days after the free gingival graft removal from the palate region. Of the 1,622 potentially relevant articles retrieved from the electronic databases, 16 RCTs were selected for qualitative analysis, and of these, 6 RCTs were included in the meta-analysis. RCTs showed a significant VAS reduction associated with the use of methods to enhance wound healing. The pooled estimates revealed a significant overall VAS reduction of 2.20 (95% CI 2.32, 2.07) 7 days after surgery. The methods that presented the greatest reduction in the perception of pain were platelet-rich fibrin, hyaluronic acid, and autologous fibrin glue. Methods that enhance wound healing, including platelet-rich fibrin, hyaluronic acid, and autologous fibrin glue, can reduce pain perception after free gingival graft removal in the palate region. However, only 1 RCT investigated each approach, which hinders the conclusion regarding the best procedure to reduce the perception of pain.

What is the impact of e-cigarettes on periodontal stem cells as revealed by transcriptomic analyses?

DESIGN: The research used an in vitro cell exposure model and multi-omics integration of transcriptome and epigenome profiling to compare the molecular effects of e-cigarettes and tobacco smoke on dental stem cells. AIM: The study aimed to compare the effects of e-cigarette and tobacco smoke on periodontal stem cells using a multi-omics approach to understand gene regulation. METHODS: This research studied primary human gingival mesenchymal stem cells (GMSCs) and periodontal ligament stem cells (PDLSCs) obtained from healthy donors. The cells were subjected to tobacco smoke, e-cigarette aerosol (both tobacco and menthol flavors), e-cigarette liquid (both tobacco and menthol flavors), or untreated conditions using an in vitro exposure system. RNA sequencing and bioinformatics analysis were used to profile the transcriptome and identify differential gene expression. Additionally, chromatin immunoprecipitation sequencing (ChIP-seq) was used to conduct genome-wide histone modification mapping for H3K27me3. Transcriptome profiling was combined with histone modification characterization to understand gene regulatory mechanisms. The study compared the effects of smoke versus e-cigarette, aerosol versus liquid exposure, and tobacco versus menthol flavor on gene expression and epigenetic landscapes in the two oral stem cell populations. RESULTS: The use of tobacco smoke caused damage to the DNA and nucleus in GMSCs, as well as mitochondrial dysfunction in PDLSCs. Regarding e-cigarettes, the aerosol and liquid affected non-coding RNA expression differently. The chemokine CXCL2 was found to be downregulated by aerosol but upregulated by liquid in GMSCs. An integrative analysis revealed that the upregulation of CXCL2 caused by e-liquid involved reduced H3K27me3 and activation of distal enhancers. On the other hand, aerosol exposure maintained H3K27me3 levels, while direct e-liquid exposure resulted in genome-wide reductions in H3K27me3, particularly in enhancer regions. Overall, the specific delivery methods and components of e-cigarettes caused unique changes in the transcriptome and epigenome of oral stem cells. CONCLUSIONS: E-cigarettes affect oral stem cells differently than tobacco smoke. Their aerosol and liquid have varying impacts on gene expression and regulatory landscapes in oral cells. Multi-omics approaches are important to understanding the molecular changes caused by e-cigarette components. This can help with toxicological assessments and determine their impact on periodontal health. Transcriptome and epigenome profiling are powerful tools to examine the unique molecular mechanisms involved in cellular responses to e-cigarettes.

Unraveling the effectiveness of antibiotics for peri-implantitis treatment: A scoping review.

BACKGROUND: Antibiotics are the most effective adjuncts in the treatment of periodontitis. However, the benefits of these agents in treating peri-implantitis are still debatable and demand further analysis. PURPOSE: The aim of this review was to critically appraise the literature on the use of antibiotics to treat peri-implantitis, with the ultimate goal of supporting evidence-based clinical recommendations, defining gaps in knowledge and guiding future studies on this topic. METHODS: A systematized literature search was conducted in MEDLINE/PubMed and Cochrane Library databases for randomized clinical trials (RCTs) on patients with peri-implantitis treated by mechanical debridement-only or with adjunctive use of local or systemic antibiotics. Clinical and microbiological data were extracted from the RCTs included. The findings were critically reviewed, interpreted, and discussed. An overview of antibiotic-loaded dental implant materials in peri-implantitis treatment was also provided. RESULTS: Twelve RCTs testing local/systemic antibiotics were included. Although not always statistically significant, all antibiotic-treated groups had greater reductions in mean PD than those treated by mechanical debridement-only. The only clinically relevant antibiotic protocol supported by one RCT with low risk of bias and long-lasting benefits was systemic metronidazole (MTZ). Studies using ultrasonic debridement reported better outcomes. No RCTs to date have tested MTZ-only or with amoxicillin (AMX) as adjuncts to open-flap implant debridement. In vitro/animal studies suggested that biomaterials with antimicrobial properties are promising to treat peri-implantitis. CONCLUSION: There are insufficient data to support a particular evidence-based antibiotic protocol to treat peri-implantitis using surgical or nonsurgical therapy, but some conclusions may be drawn. Systemic MTZ adjunct to ultrasonic debridement is an effective protocol to improve the outcomes of nonsurgical treatment. Future studies should assess the clinical and microbiological effects of MTZ and MTZ + AMX as adjuncts to optimal nonsurgical implant decontamination protocols or open-flap debridement. In addition, new locally delivered drugs and antibiotic-loaded surfaces should be assessed by RCTs.

Biomaterial engineering surface to control polymicrobial dental implant-related infections: focusing on disease modulating factors and coatings development.

INTRODUCTION: Peri-implantitis is the leading cause of dental implant loss and is initiated by a polymicrobial dysbiotic biofilm formation on the implant surface. The destruction of peri-implant tissue by the host immune response and the low effectiveness of surgical or non-surgical treatments highlight the need for new strategies to prevent, modulate and/or eliminate biofilm formation on the implant surface. Currently, several surface modifications have been proposed using biomolecules, ions, antimicrobial agents, and topography alterations. AREAS COVERED: Initially, this review provides an overview of the etiopathogenesis and host- and material-dependent modulating factors of peri-implant disease. In addition, a critical discussion about the antimicrobial surface modification mechanisms and techniques employed to modify the titanium implant material is provided. Finally, we also considered the future perspectives on the development of antimicrobial surfaces to narrow the bridge between idea and product and favor the clinical application possibility. EXPERT OPINION: Antimicrobial surface modifications have demonstrated effective results; however, there is no consensus about the best modification strategy and in-depth information on the safety and longevity of the antimicrobial effect. Modified surfaces display recurring challenges such as short-term effectiveness, the burst release of drugs, cytotoxicity, and lack of reusability. Stimulus-responsive surfaces seem to be a promising strategy for a controlled and precise antimicrobial effect, and future research should focus on this technology and study it from models that better mimic clinical conditions.

Effect of Processing Methods of Human Saliva on the Proteomic Profile and Protein-Mediated Biological Processes.

The use of saliva as a protein source prior to microbiological and biological assays requires previous processing. However, the effect of these processing methods on the proteomic profile of saliva has not been tested. Stimulated human saliva was collected from eight healthy volunteers. Non-processed saliva was compared with 0.22 µm filtered, 0.45 µm filtered, and pasteurized saliva, by liquid chromatography-mass spectrometry. Data are available via ProteomeXchange with identifier PXD039248. The effect of processed saliva on microbial adhesion was tested using bacterial and fungus species and in biological cell behavior using HaCaT immortalized human keratinocytes. Two hundred and seventy-eight proteins were identified in non-processed saliva, of which 54 proteins (≈19%) were exclusive. Saliva processing reduced identified proteins to 222 (≈80%) for the 0.22 µm group, 219 (≈79%) for the 0.45 µm group, and 201 (≈72%) for the pasteurized saliva, compared to non-processed saliva. The proteomic profile showed similar molecular functions and biological processes. The different saliva processing methods did not alter microbial adhesion (ANOVA, p > 0.05). Interestingly, pasteurized saliva reduced keratinocyte cell viability. Saliva processing methods tested reduced the proteomic profile diversity of saliva but maintained similar molecular functions and biological processes, not interfering with microbial adhesion and cell viability, except for pasteurization, which reduced cell viability.

Is there an effective way to control pain perception after free gingival graft removal? A systematic review and meta-analysis

Abstract The literature describes multiple ways to stimulate wound healing to reduce the patient's perception of pain. This systematic review aimed to evaluate if methods that enhance wound healing can reduce the patient's perception of pain after free gingival graft removal from the palate region compared to natural healing. A systematic review protocol was written following the PRISMA checklist. Electronic searches of five databases were performed to identify randomized clinical trials (RCTs) that assessed the patient's perception of pain after the removal of a free gingival graft from the palate. The primary outcome was the visual analog scale (VAS) score assessing the patient's perception of pain 7 days after the free gingival graft removal from the palate region. Of the 1,622 potentially relevant articles retrieved from the electronic databases, 16 RCTs were selected for qualitative analysis, and of these, 6 RCTs were included in the meta-analysis. RCTs showed a significant VAS reduction associated with the use of methods to enhance wound healing. The pooled estimates revealed a significant overall VAS reduction of 2.20 (95% CI 2.32, 2.07) 7 days after surgery. The methods that presented the greatest reduction in the perception of pain were platelet-rich fibrin, hyaluronic acid, and autologous fibrin glue. Methods that enhance wound healing, including platelet-rich fibrin, hyaluronic acid, and autologous fibrin glue, can reduce pain perception after free gingival graft removal in the palate region. However, only 1 RCT investigated each approach, which hinders the conclusion regarding the best procedure to reduce the perception of pain.

Resumo A literatura descreve diferentes formas de estimular a cicatrização para reduzir a percepção de dor do paciente. Esta revisão sistemática teve como objetivo avaliar se métodos que melhoram o reparo de feridas podem reduzir a percepção de dor do paciente após a remoção de enxerto gengival livre da região do palato quando comparado a cicatrização natural. Um protocolo de revisão sistemática foi escrito seguindo a lista de verificação PRISMA. Pesquisas eletrônicas em cinco bancos de dados foram realizadas para identificar ensaios clínicos aleatorizados (ECA) que avaliaram a percepção de dor do paciente após a remoção do enxerto gengival livre do palato. O desfecho primário foi o escore da escala visual analógica (VAS) avaliando a percepção de dor do paciente 7 dias após a remoção do enxerto gengival livre da região do palato. Dos 1.622 artigos potencialmente relevantes recuperados das bases de dados eletrônicas, 16 ECAs foram selecionados para análise qualitativa, e destes, seis ECAs foram incluídos na meta-análise. Os estudos analisados demonstraram uma redução significativa de VAS associada ao uso de métodos para melhorar a cicatrização de feridas. As estimativas agrupadas revelaram uma redução global significativa do VAS de 2,20 (95% CI 2,32, 2,07) 7 dias após a cirurgia. Os métodos que apresentaram maior redução na percepção de dor foram fibrina rica em plaquetas, ácido hialurônico e cola de fibrina autóloga. Métodos que melhoram a cicatrização de feridas podem reduzir a percepção de dor após a remoção do enxerto gengival livre na região do palato, especialmente fibrina rica em plaquetas, ácido hialurônico e cola de fibrina autóloga. No entanto, apenas um ECA avaliou cada abordagem, o que impossibilita a conclusão sobre qual é o melhor procedimento para reduzir a percepção de dor.

Emerging titanium surface modifications: The war against polymicrobial infections on dental implants.

Dental implants made of titanium (Ti) material is recognized as the leading treatment option for edentulous patients' rehabilitation, showing a high success rate and clinical longevity. However, dental implant surface acts as a platform for microbial adhesion and accumulation once exposed to the oral cavity. Biofilm formation on implant surfaces has been considered the main etiologic factor to induce inflammatory diseases, known as peri-implant mucositis and peri-implantitis; the latter being recognized as the key reason for late dental implant failure. Different factors, such as biofilm matrix production, source of carbohydrate exposure, and cross-kingdom interactions, have encouraged increased microbial accumulation on dental implants, leading to a microbiological community shift from a healthy to a pathogenic state, increasing inflammation and favoring tissue damage. These factors combined with the spatial organization of biofilms, reduced antimicrobial susceptibility, complex microbiological composition, and the irregular topography of implants hamper biofilm control and microbial killing. In spite of the well-known etiology, there is still no consensus regarding the best clinical protocol to control microbial accumulation on dental implant surfaces and treat peri-implant disease. In this sense, different coatings and Ti surface treatments have been proposed in order to reduce microbial loads and control polymicrobial infections on implantable devices. Therefore, this critical review aims to discuss the current evidence on biofilm accumulation on dental implants and central factors related to the pathogenesis process of implant-related infections. Moreover, the potential surface modifications with anti-biofilm properties for dental implant devices is discussed to shed light on further promising strategies to control peri-implantitis.

Cross-kingdom microbial interactions in dental implant-related infections: is Candida albicans a new villain?

Candida albicans, an oral fungal opportunistic pathogen, has shown the ability to colonize implant surfaces and has been frequently isolated from biofilms associated with dental implant-related infections, possibly due to its synergistic interactions with certain oral bacteria. Moreover, evidence suggests that this cross-kingdom interaction on implant can encourage bacterial growth, leading to increased fungal virulence and mucosal damage. However, the role of Candida in implant-related infections has been overlooked and not widely explored or even considered by most microbiological analyses and therapeutic approaches. Thus, we summarized the scientific evidence regarding the ability of C. albicans to colonize implant surfaces, interact in implant-related polymicrobial biofilms, and its possible role in peri-implant infections as far as biologic plausibility. Next, a systematic review of preclinical and clinical studies was conducted to identify the relevance and the gap in the existing literature regarding the role of C. albicans in the pathogenesis of peri-implant infections.

Mapping Bone Marrow Cell Response from Senile Female Rats on Ca-P-Doped Titanium Coating.

Chemical and topographical surface modifications on dental implants aim to increase the bone surface contact area of the implant and improve osseointegration. This study analyzed the cellular response of undifferentiated mesenchymal stem cells (MSC), derived from senile rats' femoral bone marrow, when cultured on a bioactive coating (by plasma electrolytic oxidation, PEO, with Ca2+ and P5+ ions), a sandblasting followed by acid-etching (SLA) surface, and a machined surface (MSU). A total of 102 Ti-6Al-4V discs were divided into three groups (n = 34). The surface chemistry was analyzed by energy dispersive spectroscopy (EDS). Cell viability assay, gene expression of osteoblastic markers, and mineralized matrix formation were investigated. The cell growth and viability results were higher for PEO vs. MSU surface (p = 0.001). An increase in cell proliferation from 3 to 7 days (p < 0.05) and from 7 to 10 days (p < 0.05) was noted for PEO and SLA surfaces. Gene expression for OSX, ALP, BSP, and OPN showed a statistical significance (p = 0.001) among groups. In addition, the PEO surface showed a higher mineralized matrix bone formation (p = 0.003). In conclusion, MSC from senile female rats cultured on SLA and PEO surfaces showed similar cellular responses and should be considered for future clinical investigations.

Emerging titanium surface modifications: The war against polymicrobial infections on dental implants

Abstract Dental implants made of titanium (Ti) material is recognized as the leading treatment option for edentulous patients' rehabilitation, showing a high success rate and clinical longevity. However, dental implant surface acts as a platform for microbial adhesion and accumulation once exposed to the oral cavity. Biofilm formation on implant surfaces has been considered the main etiologic factor to induce inflammatory diseases, known as peri-implant mucositis and peri-implantitis; the latter being recognized as the key reason for late dental implant failure. Different factors, such as biofilm matrix production, source of carbohydrate exposure, and cross-kingdom interactions, have encouraged increased microbial accumulation on dental implants, leading to a microbiological community shift from a healthy to a pathogenic state, increasing inflammation and favoring tissue damage. These factors combined with the spatial organization of biofilms, reduced antimicrobial susceptibility, complex microbiological composition, and the irregular topography of implants hamper biofilm control and microbial killing. In spite of the well-known etiology, there is still no consensus regarding the best clinical protocol to control microbial accumulation on dental implant surfaces and treat peri-implant disease. In this sense, different coatings and Ti surface treatments have been proposed in order to reduce microbial loads and control polymicrobial infections on implantable devices. Therefore, this critical review aims to discuss the current evidence on biofilm accumulation on dental implants and central factors related to the pathogenesis process of implant-related infections. Moreover, the potential surface modifications with anti-biofilm properties for dental implant devices is discussed to shed light on further promising strategies to control peri-implantitis.

Resumo Implantes dentários em titânio (Ti) são reconhecidos como principal modalidade terapêutica para a reabilitação oral de pacientes edêntulos, demonstrando uma alta taxa de sucesso e longevidade clínica. No entanto, após inserção no ambiente bucal, os implantes dentários agem como substrato para adesão e acúmulo microbiano. A formação de biofilmes em implantes dentários tem sido considerada o principal fator etiológico para induzir doenças inflamatórias conhecidas como mucosite peri-implantar e peri-implantite, sendo está última reconhecida como principal razão para falha tardia dos implantes dentários. Diferentes fatores têm sido atribuídos por promover o acúmulo microbiano em implantes dentários, levando a uma mudança microbiológica e favorecendo o dano tecidual, como a matriz do biofilme, exposição a carboidratos e interação entre reinos. Esses fatores combinados com a organização espacial de biofilmes, reduzida suscetibilidade microbiana, complexa composição microbiológica e a superfície irregular dos implantes dificultam o controle do biofilme e a morte microbiana. Apesar da etiologia bem conhecida, ainda não há consenso sobre o melhor protocolo clínico para controlar o acúmulo microbiano nas superfícies dos implantes dentários e tratar a doença peri-implantar. Nesse sentido, diferentes coberturas e tratamentos de superfície no Ti têm sido desenvolvidos objetivando a redução dos níveis microbianos e o controle das infecções polimicrobianas em implantes. Portanto, essa revisão crítica objetiva discutir a atual evidência em relação ao acúmulo de biofilmes em implantes dentários e fatores chave relacionados ao processo patogênico das infecções peri-implantares. Além disso, o potencial de alterações de superfícies com propriedades antimicrobianas para implantes dentários é discutido para ressaltar futuras estratégias promissoras no controle da peri-implantite.

Association between industry support and the reporting of study outcomes in randomized clinical trials of dental implant research from the past 20 years.

BACKGROUND: Industry support is a significant funding source in implant dentistry research, not only to provide regulatory processes, but also to validate and promote products through randomized clinical trials (RCTs). However, industry funding should not affect scientific outcomes. PURPOSE: The aim of this study was to investigate whether there is an association between industry support for RCTs in implant dentistry and a greater chance of the reporting of positive outcomes, and whether there are other funding tendencies. MATERIALS AND METHODS: Randomized clinical trials from five implant dentistry journals were reviewed. Data were extracted, and descriptive and inferential statistical analyses (α = 0.05), including bivariate and multivariable logistic regression, and Spearman's correlation were performed. RESULTS: Two hundred eleven RCTs were included. Industry-funded and -unfunded studies presented similar outcomes, in terms of positive and negative results (p ≥ 0.05). North American and European countries received more industry funding, as did high-income countries, which showed well-established collaboration with each other. Clinical Oral Implants Research and Clinical Implant Dentistry and Related Research published 83.6% of industry-funded articles. Industry-funded studies from middle-income countries established more international collaborations with high-income countries than did unfunded studies. Citation numbers were similar for funded and unfunded studies. The chance of RCTs being industry-funded was higher for high-income (odds ratio [OR] = 3.00; 95% confidence interval [CI], 0.99-9.32; p = 0.05) and North American articles (OR = 3.40; 95% CI, 1.37-8.42; p = 0.008) than in lower-middle-income and other continents, respectively. Higher industry funding was associated with specific topics such as "surgical procedures," "prosthodontics topics," and "implant macrodesign" (OR = 4.7; 95% CI, 1.45-15.20; p = 0.010) and with the increase in numbers of institutions (OR = 1.52; 95% CI, 1.16-2.0; p = 0.002). CONCLUSION: The available evidence suggests no association between industry funding and greater chances of the reporting of positive outcomes in implant dentistry RCTs. A strong association was identified in industry trends concerning geographic origins, higher numbers of institutions, and specific research topics.

Fitting pieces into the puzzle: The impact of titanium-based dental implant surface modifications on bacterial accumulation and polymicrobial infections.

Polymicrobial infection is the main cause of dental implant failure. Although numerous studies have reported the ability of titanium (Ti) surface modifications to inhibit microbial adhesion and biofilm accumulation, the majority of solutions for the utilization of Ti antibacterial surfaces have been testedin in vitro and animal models, with only a few developed surfaces progressing into clinical research. Motivated by this huge gap, we critically reviewed the scientific literature on the existing antibacterial Ti surfaces to help understand these surfaces' impact on the "puzzle" of undesirable dental implant-related infections. This manuscript comprises three main sections: (i) a narrative review on topics related to oral biofilm formation, bacterial-implant surface interactions, and on how implant-surface modifications can influence microbial accumulation; (ii) a critical evidence-based review to summarize pre-clinical and clinical studies in an attempt to "fit pieces into the puzzle" to unveil the best way to reduce microbial loads and control polymicrobial infection around dental implants showed by the current in vivo evidence; and (iii) discussion and recommendations for future research testing emerging antibacterial implant surfaces, connecting basic science and the requirements for future clinical translation. The findings of the present review suggest no consensus regarding the best available Ti surface to reduce bacterial colonization on dental implants. Smart release or on-demand activation surface coatings are a "new piece of the puzzle", which may be the most effective alternative for reducing microbial colonization on Ti surfaces, and future studies should focus on these technologies.

Clinical and Histological Manifestations of Chronic Coca Leaf Chewing in a Peruvian Population: A Cross-sectional Study.

AIMS: This study aimed to determine the possible clinical and histological periodontal effects of long-term coca leaf chewing habit in habitants of the highland region of Peru. MATERIALS AND METHODS: A total of 100 residents, were recruited for the study. Fifty individuals were habitual coca leaf chewers and 50 were non-users. Eligibility criteria were: 60-80 years old, ≥20 teeth present (excluding third molars), systemically healthy (controlled systemic disease), not using medication affecting the gingiva. Chronic tobacco smokers were excluded. All participants completed questionnaires, received clinical periodontal examination, and had gingival biopsies harvested for histopathological assessment. RESULTS: Most coca leaf chewers reported several oral changes resulting from the habit, such as bitterness, numbness and mouth dryness, while none of the non-chewers reported experiencing such changes. Within the clinical periodontal parameters, it was found that there was a significant difference in terms of clinical attachment level loss, with a p value of 0.014 in those who chewed coca leaves, who appeared to have less clinical attachment loss. CONCLUSIONS: Chewing coca leaf produce bitterness, numbness and mouth dryness, and clinical attachment loss. Histologically higher number of inflammatory cells in the stratum spinosum, with more acanthosis, clear cell, and higher number of blood vessels.

Lateral static overload on immediately restored implants decreases the osteocyte index in peri-implant bone: a secondary analysis of a pre-clinical study in dogs.

OBJECTIVES: This animal study was conducted to evaluate the osteocyte index in the peri-implant bone around immediately restored implants under static lateral overload. MATERIAL AND METHODS: Seven mongrel dogs received three implants on each side of the mandible. Forty-two implants were distributed into three groups (14 implants per group); each animal received two implants connected to a 4.5-mm opened expansion device (experimental group); in the other mandible side, two implants were connected into an expansion device without activation (control group); one implant each side of the mandible was left submerged (unload group). After 4 months under daily mechanical and chemical plaque control, the animals were euthanized; dental implants and surrounding bone were removed and processed to obtain thin ground sections. Histomorphometry was used to evaluate the osteocyte index in the peri-implant bone contact to implant. RESULTS: A higher, statistically significant mean number of osteocytes × 10-5 µm2 (54.74 ± 23.91) was found in the control group compared with the test group (22.57 ± 22.55) (p = 0.0221). The correlation between percentage of bone-implant contact and osteocyte index for submerged implants was not statistically significant (p = 0.2667), whereas the value for immediately loaded implants was statistically significant (p = 0.0480). CONCLUSION: The lower number of osteocytes in the peri-implant bone around overloaded implants could be related to the need for functional adaptation of the bone tissue to overloading and to the hypothesized involvement of the osteocytes in the maintenance of the bone matrix in the control group. CLINICAL RELEVANCE: Osteocytes play a pivotal role in bone adaptation to mechanical loading, and the osteocyte network has been regarded as being the main mechanosensory mechanism.

Transcriptomic and Morphological Analysis of Cells Derived from Porcine Buccal Mucosa-Studies on an In Vitro Model.

Transcriptional analysis and live-cell imaging are a powerful tool to investigate the dynamics of complex biological systems. In vitro expanded porcine oral mucosal cells, consisting of populations of epithelial and connective lineages, are interesting and complex systems for study via microarray transcriptomic assays to analyze gene expression profile. The transcriptomic analysis included 56 ontological groups with particular focus on 7 gene ontology groups that are related to the processes of differentiation and development. Most analyzed genes were upregulated after 7 days and downregulated after 15 and 30 days of in vitro culture. The performed transcriptomic analysis was then extended to include automated analysis of differential interference contrast microscopy (DIC) images obtained during in vitro culture. The analysis of DIC imaging allowed to identify the different populations of keratinocytes and fibroblasts during seven days of in vitro culture, and it was possible to evaluate the proportion of these two populations of cells. Porcine mucosa may be a suitable model for reference research on human tissues. In addition, it can provide a reference point for research on the use of cells, scaffolds, or tissues derived from transgenic animals for applications in human tissues reconstruction.

New Gene Markers Involved in Molecular Processes of Tissue Repair, Response to Wounding and Regeneration Are Differently Expressed in Fibroblasts from Porcine Oral Mucosa during Long-Term Primary Culture.

The mechanisms of wound healing and vascularization are crucial steps of the complex morphological process of tissue reconstruction. In addition to epithelial cells, fibroblasts play an important role in this process. They are characterized by dynamic proliferation and they form the stroma for epithelial cells. In this study, we have used primary cultures of oral fibroblasts, obtained from porcine buccal mucosa. Cells were maintained long-term in in vitro conditions, in order to investigate the expression profile of the molecular markers involved in wound healing and vascularization. Based on the Affymetrix assays, we have observed three ontological groups of markers as wound healing group, response to wounding group and vascularization group, represented by different genes characterized by their expression profile during long-term primary in vitro culture (IVC) of porcine oral fibroblasts. Following the analysis of gene expression in three previously identified groups of genes, we have identified that transforming growth factor beta 1 (TGFB1), ITGB3, PDPN, and ETS1 are involved in all three processes, suggesting that these genes could be recognized as markers of repair specific for oral fibroblasts within the porcine mucosal tissue.

Mechanical Properties of the Mandible in Postmenopausal Women Under Aledronate Treatment.

AIMS: This study evaluated the mechanical properties of mandibular bone tissue retrieved from postmenopausal women under alendronate treatment. METHODS: Twenty postmenopausal women were divided into two groups: healthy postmenopausal subjects (control group) and osteoporotic subjects treated with alendronate (alendronate group). Mandibular bone samples were retrieved with a trephine bur at the time of dental implant placement and fixed in 4% formalin. Samples were processed for hard tissue histology, and the bone surface was analyzed for nanohardness measurement. Nanohardness and elastic modulus were evaluated by using a Berkovich tip with elastic modulus of 1.016x106 MPa, Poisson coefficient of 0.3, and a load of 100 mN. Each cycle was configured with a load time of 18 seconds (speed of 1 mN/second), the discharge time of 18 seconds, and a rest time of 5 seconds during indentation at a depth of 10 µm. RESULTS: The control group presented the highest values for nanohardness and elastic modulus (p less than 0.05) in relation to the osteoporotic subjects. CONCLUSIONS: Within the limitations of the study, it can be concluded that treatment with alendronate negatively influenced the mechanical properties of mandibular bone in postmenopausal women by reducing bone nanohardness and elastic modulus.

Stemness Potency of Human Gingival Cells-Application in Anticancer Therapies and Clinical Trials.

Gingivae, as the part of periodontium, are involved in tooth support and possess the ability to heal rapidly, without scar formation. Recently, dental tissues have been identified as a potential source of mesenchymal stem cells (MSCs) and several populations of MSCs were isolated from the orofacial region, including gingival mesenchymal stem cells (GMSCs). GMSCs exhibit robust immunomodulatory and differentiation potential and are easily obtainable, which make them promising candidates for cellular therapies. Apart from being tested for application in immunologic- and inflammatory-related disorders and various tissue regeneration, GMSCs promise to be a valuable tool in cancer treatment, especially in tongue squamous cell carcinoma (TSCC) with the use of targeted therapy, since GMSCs are able to selectively migrate towards the cancerous cells both in vitro and in vivo. In addition to their ability to uptake and release anti-neoplastic drugs, GMSCs may be transduced with apoptosis-inducing factors and used for cancer growth inhibition. Moreover, GMSCs, as most mammalian cells, secrete exosomes, which are a subset of extracellular vesicles with a diameter of 40-160 nm, containing DNA, RNA, lipids, metabolites, and proteins. Such GMSCs-derived exosomes may be useful therapeutic tool in cell-free therapy, as well as their culture medium. GMSCs exhibit molecular and stem-cell properties that make them well suited in preclinical and clinical studies.