Implant surface modifications and their impact on osseointegration and peri-implant diseases through epigenetic changes: A scoping review.

Dental implant surfaces and their unique properties can interact with the surrounding oral tissues through epigenetic cues. The present scoping review provides current perspectives on surface modifications of dental implants, their impact on the osseointegration process, and the interaction between implant surface properties and epigenetics, also in peri-implant diseases. Findings of this review demonstrate the impact of innovative surface treatments on the epigenetic mechanisms of cells, showing promising results in the early stages of osseointegration. Dental implant surfaces with properties of hydrophilicity, nanotexturization, multifunctional coatings, and incorporated drug-release systems have demonstrated favorable outcomes for early bone adhesion, increased antibacterial features, and improved osseointegration. The interaction between modified surface morphologies, different chemical surface energies, and/or release of molecules within the oral tissues has been shown to influence epigenetic mechanisms of the surrounding tissues caused by a physical-chemical interaction. Epigenetic changes around dental implants in the state of health and disease are different. In conclusion, emerging approaches in surface modifications for dental implants functionalized with epigenetics have great potential with a significant impact on modulating bone healing during osseointegration.

Recent advances in additive manufacturing of patient-specific devices for dental and maxillofacial rehabilitation.

OBJECTIVES: Customization and the production of patient-specific devices, tailoring the unique anatomy of each patient's jaw and facial structures, are the new frontiers in dentistry and maxillofacial surgery. As a technological advancement, additive manufacturing has been applied to produce customized objects based on 3D computerized models. Therefore, this paper presents advances in additive manufacturing strategies for patient-specific devices in diverse dental specialties. METHODS: This paper overviews current 3D printing techniques to fabricate dental and maxillofacial devices. Then, the most recent literature (2018-2023) available in scientific databases reporting advances in 3D-printed patient-specific devices for dental and maxillofacial applications is critically discussed, focusing on the major outcomes, material-related details, and potential clinical advantages. RESULTS: The recent application of 3D-printed customized devices in oral prosthodontics, implantology and maxillofacial surgery, periodontics, orthodontics, and endodontics are presented. Moreover, the potential application of 4D printing as an advanced manufacturing technology and the challenges and future perspectives for additive manufacturing in the dental and maxillofacial area are reported. SIGNIFICANCE: Additive manufacturing techniques have been designed to benefit several areas of dentistry, and the technologies, materials, and devices continue to be optimized. Image-based and accurately printed patient-specific devices to replace, repair, and regenerate dental and maxillofacial structures hold significant potential to maximize the standard of care in dentistry.

Classifying Maxillary Sinuses of Polish Patients for Sinus Lift: A Pilot Study.

To date, there is no systematic anatomical classification available that could help clinicians in choosing between the lateral and palatal approach in sinus lift procedures. The aim was to provide a simple-to-use and memorable classification of the maxillary sinus concerning the thickness of lateral and palatal walls to facilitate the most adequate choice for the window location during direct sinus floor elevation. Cone beam computed tomography scans were consecutively obtained for 200 maxillary sinuses of patients needing dental implant placement with potential maxillary sinus augmentation. The thickness and height of the alveolar bone of the lateral and palatal walls of the maxillary sinuses were assessed. Four variants were distinguished. Class 0: an adequate sub-sinus residual bone height; without the need for sinus floor augmentation. Classes 1-3 had a reduced sub-sinus residual bone height. Class 1: a thinner lateral than palatal sinus wall. Class 2 (the most frequent; 49%): the comparable thickness of both walls in which either lateral, palatal, or crestal window osteotomies can be applied. Class 3 (the least frequent; 3%): a thinner palatal sinus wall in comparison to the lateral wall. The presented anatomical classification simplifies the decision-making process of choosing the most adequate window location and osteotomy technique.

Polymorphism in epigenetic regulating genes in relation to periodontitis, number of teeth, and levels of high-sensitivity C-reactive protein and glycated hemoglobin: The Tromsø Study 2015-2016.

BACKGROUND: The aim of this study was to investigate the association between periodontitis and four single nucleotide polymorphisms (SNPs) in genes involved in epigenetic regulation of DNA, and between these same SNPs and tooth loss, high-sensitivity C-reactive protein (hs-CRP), and glycated hemoglobin (HbA1c) levels. METHODS: We included participants with periodontal examination (n = 3633, aged: 40-93 years) from the Tromsø Study seventh survey (2015-2016), Norway. Periodontitis was defined according to the 2017 AAP/EFP classification system as no periodontitis, grades A, B, or C. Salivary DNA was extracted and genotyping was performed to investigate four SNPs (rs2288349, rs35474715, rs34023346, and rs10010325) in the sequence of the genes DNMT1, IDH2, TET1, and TET2. Association between SNPs and periodontitis was analyzed by logistic regression adjusted for age, sex, and smoking. Subgroup analyses on participants aged 40-49 years were performed. RESULTS: In participants aged 40-49 years, homozygous carriage of minor A-allele of rs2288349 (DNMT1) was associated with decreased susceptibility to periodontitis (grade A: odds ratio [OR] 0.55; p = 0.014: grade B/C OR 0.48; p = 0.004). The minor A-allele of rs10010325 (TET2) was associated with increased susceptibility to periodontitis (grade A OR 1.69; p = 0.035: grade B/C OR 1.90; p = 0.014). In the entire sample, homozygous carriage of the G-allele of rs35474715 (IDH2) was associated with having ≤24 teeth (OR 1.31; p = 0.018). Homozygous carriage of the A-allele of TET2 was associated with hs-CRP≥3 mg/L (OR 1.37; p = 0.025) and HbA1c≥6.5% (OR 1.62; p = 0.028). CONCLUSIONS: In this Norwegian population, there were associations between polymorphism in genes related to DNA methylation and periodontitis, tooth loss, low-grade inflammation, and hyperglycemia.

The Role of Titanium Particles and Ions in the Pathogenesis of Peri-Implantitis.

Titanium (Ti) particles and ions have been investigated in recent years as important factors in the pathogenesis of peri-implantitis. However, their role in the pathogenesis is yet to be fully understood. A review of pertinent literature was performed in various databases to determine the current position of Ti particles and ions role in the pathogenesis of peri-implantitis. There are several in vitro, preclinical and clinical published studies that have addressed the role of Ti particles and ions in the pathogenesis of peri-implantitis. These studies explored the effect of Ti particles and ions in the pathogenesis of peri-implantitis with respect to foreign body reaction, cellular response, epigenetic mechanisms, namely DNA methylation, and the oral microbiome. Studies have shown that the release of Ti particles/ions during implant insertion, early healing stages, late healing stages, and treatments during peri-implantitis might contribute to peri-implantitis through different mechanisms, such as foreign body reaction, cellular response, DNA methylation, and shaping the oral microbiome by increasing dysbiosis. However, further studies are needed to elucidate the complex interactions between all these mechanisms and Ti particles/ions in the pathogenesis and progression of peri-implantitis.

Global DNA Methylation in Dental Implant Failure Due to Peri-Implantitis: An Exploratory Clinical Pilot Study.

BACKGROUND: Peri-implantitis (PIT) is highly prevalent in patients with dental implants and is a challenging condition to treat due to the limited outcomes reported for non-surgical and surgical therapies. Therefore, epigenetic therapeutics might be of key importance to treat PIT. However, developing epigenetic therapeutics is based on understanding the relationship between epigenetics and disease. To date, there is still scarce knowledge about the relationship between epigenetic modifications and PIT, which warrants further investigations. AIM: The purpose of this study was to evaluate the level of global DNA methylation associated with implant failure (IF) due to PIT compared to periodontally healthy (PH) patients. MATERIAL AND METHODS: A total of 20 participants were initially enrolled in this pilot, exploratory, single-blinded, cross-sectional clinical human study in two groups: 10 in the PH group and 10 in the IF group. In the participants who have completed the study, gingival tissue and bone samples were harvested from each participant and were used to perform global DNA methylation analysis. The percentage of global DNA methylation (5-mC%) was compared (1) between groups (PH and IF); (2) between the subgroups of gingival tissue and bone separately; (3) in the whole sample, comparing gingival tissue and bone; (4) within groups, comparing gingival tissue and bone. Demographic, periodontal, and peri-implant measurements as well as periodontal staging, were also recorded. All statistical comparisons were made at the 0.05 significance level. RESULTS: Out of the initially enrolled 20 patients, only 19 completed the study and, thus, were included in the final analysis; 10 patients in the PH group and 9 patients in the IF group, contributing to a total of 38 samples. One patient from the IF group was excluded from the study due to systemic disease. The mean implant survival time was 10.8 years (2.17-15.25 years). Intergroup comparison, stratified by group, indicated a similar 5-mC% between the PH and IF groups in both gingival tissue and bone (p = 0.599), only in bone (p = 0.414), and only in gingival tissue (p = 0.744). Intragroup comparison, stratified by the type of sample, indicated a significantly higher 5-mC% in gingival tissue samples compared to bone in both the PH and IF groups (p = 0.001), in the PH group (p = 0.019), and in the IF group (p = 0.009). CONCLUSIONS: Within the limitations of this study, higher global DNA methylation levels were found in gingival tissue samples compared to bone, regardless of the study groups. However, similar global DNA methylation levels were observed overall between the IF and PH groups. Yet, differences in the global DNA methylation levels between gingival tissues and bone, regardless of the study group, could reflect a different epigenetic response between various tissues within the same microenvironment. Further studies are necessary to elucidate the present findings and to evaluate the role of epigenetic modifications in IF due to PIT.

Understanding the role of endotoxin tolerance in chronic inflammatory conditions and periodontal disease.

OBJECTIVE: This review aims to present the current understanding of endotoxin tolerance (ET) in chronic inflammatory diseases and explores the potential connection with periodontitis. SUMMARY: Subsequent exposure to lipopolysaccharides (LPS) triggers ET, a phenomenon regulated by different mechanisms and pathways, including toll-like receptors (TLRs), nuclear factor kappa-light-chain enhancer of activated B-cells (NFκB), apoptosis of immune cells, epigenetics, and microRNAs (miRNAs). These mechanisms interconnect ET with chronic inflammatory diseases including periodontitis. While the direct correlation between ET and periodontal destruction has not been fully elucidated, emerging reports point towards the potential tolerization of human periodontal ligament cells (hPDLCs) and gingival tissues with a significant reduction of TLR levels. CONCLUSIONS: There is a potential link between ET and periodontal diseases. Future studies should explore the crucial role of ET in the pathogenesis of periodontal diseases, as evidence of a tolerized oral mucosa may represent an intrinsic mechanism capable of regulating the oral immune response. A clear understanding of this host immune regulatory mechanism might lead to effective and more predictable therapeutic strategies to treat chronic inflammatory diseases and periodontitis.

Aesthetic outcomes of non-functional immediately restored single post-extraction implants with and without connective tissue graft: A multicentre randomized controlled trial.

OBJECTIVES: To compare the 1-year aesthetic results of flapless single implants, placed in fresh extraction sockets with bone replacement and immediate provisional restoration with or without a connective tissue graft (CTG). MATERIAL AND METHODS: The present study proposes a partially blinded multicentre parallel randomized controlled trial, where computer-generated tables were used for central randomization to allocate treatments. A total of 59 of the 60 patients screened by eight private practices in Northern Italy fulfilled the inclusion criteria. Immediate implants were placed in a fresh extraction socket with a non-functional immediate provisional restoration with (Test group) or without (Control group) a CTG. The primary outcome variable was the implant Crown Aesthetic Index (ICAI) at the 1-year follow-up. RESULTS: ICAI for the 59 randomized patients (Test group = 31, Control group = 28) at the 1-year follow-up was 4.69 (95% CI = 3.16-6.22) for the Test group and 3.45 (95% CI = 1.83-5.08) for the Control group, without statistically significant difference between the two groups (p = .086). One implant failure was recorded in each group, resulting in an implant survival rate of 96.8% [95% CI = 83.3-99.9] for the Test group and 96.4% [95% CI = 81.7-99.9] for the Control group. Other secondary outcome variables and complication rates were comparable across the two groups. CONCLUSIONS: Within the limitations of the present clinical trial, the results suggested that the adjunct use of CTG is not mandatory to achieve successful aesthetic outcomes for a well-planned immediate implant placement with immediate non-functional provisional restoration in a fresh extraction socket.

Epigenetic changes of osteoblasts in response to titanium surface characteristics.

We aimed to investigate the influence of titanium surface characteristics on epigenetic mechanisms and DNA damage/repair pathways. Osteoblast-like cells (MG63) were incubated on glass, smooth titanium, and minimally rough titanium discs, respectively, for 0, 1, 6, and 24 hr. The presence of double-stranded DNA damage (γH2AX), DNA repair (Chk2), and epigenetic markers (AcH3 & DNMT1) were investigated using immunofluorescence. There were no Chk2-positive cells on the minimally rough titanium surfaces at all-time points, in comparison to glass and smooth titanium. Total γH2AX-positive cells on minimally rough titanium gradually decreased as incubation time increased, on the contrary to smooth titanium. Minimally rough titanium surfaces induced cytoplasmic staining of DNMT1 up to 99% at 24 hr. For epigenetic markers related to the DNA damage/repair pathway, minimally rough titanium surfaces showed the lower percentage of AcH3-positive cells compared to glass and smooth titanium surface. The findings in the current study show that titanium surface characteristics indeed influence DNA damage and the DNA repair pathway, including epigenetic factors.

The Role of Epigenetic Functionalization of Implants and Biomaterials in Osseointegration and Bone Regeneration-A Review.

The contribution of epigenetic mechanisms as a potential treatment model has been observed in cancer and autoimmune/inflammatory diseases. This review aims to put forward the epigenetic mechanisms as a promising strategy in implant surface functionalization and modification of biomaterials, to promote better osseointegration and bone regeneration, and could be applicable for alveolar bone regeneration and osseointegration in the future. Materials and Methods: Electronic and manual searches of the literature in PubMed, MEDLINE, and EMBASE were conducted, using a specific search strategy limited to publications in the last 5 years to identify preclinical studies in order to address the following focused questions: (i) Which, if any, are the epigenetic mechanisms used to functionalize implant surfaces to achieve better osseointegration? (ii) Which, if any, are the epigenetic mechanisms used to functionalize biomaterials to achieve better tissue regeneration? Findings from several studies have emphasized the role of miRNAs in functionalizing implants surfaces and biomaterials to promote osseointegration and bone regeneration, respectively. However, there are scarce data on the role of DNA methylation and histone modifications for these specific applications, despite being commonly applied in cancer research. Studies over the past few years have demonstrated that biomaterials are immunomodulatory rather than inert materials. In this context, epigenetics can act as next generation of advanced treatment tools for future regenerative techniques. Yet, there is a need to evaluate the efficacy/cost effectiveness of these techniques in comparison to current standards of care.

The Role of DNA Methylation and Histone Modification in Periodontal Disease: A Systematic Review.

Despite a number of reports in the literature on the role of epigenetic mechanisms in periodontal disease, a thorough assessment of the published studies is warranted to better comprehend the evidence on the relationship between epigenetic changes and periodontal disease and its treatment. Therefore, the aim of this systematic review is to identify and synthesize the evidence for an association between DNA methylation/histone modification and periodontal disease and its treatment in human adults. A systematic search was independently conducted to identify articles meeting the inclusion criteria. DNA methylation and histone modifications associated with periodontal diseases, gene expression, epigenetic changes after periodontal therapy, and the association between epigenetics and clinical parameters were evaluated. Sixteen studies were identified. All included studies examined DNA modifications in relation to periodontitis, and none of the studies examined histone modifications. Substantial variation regarding the reporting of sample sizes and patient characteristics, statistical analyses, and methodology, was found. There was some evidence, albeit inconsistent, for an association between DNA methylation and periodontal disease. IL6, IL6R, IFNG, PTGS2, SOCS1, and TNF were identified as candidate genes that have been assessed for DNA methylation in periodontitis. While several included studies found associations between methylation levels and periodontal disease risk, there is insufficient evidence to support or refute an association between DNA methylation and periodontal disease/therapy in human adults. Further research must be conducted to identify reproducible epigenetic markers and determine the extent to which DNA methylation can be applied as a clinical biomarker.

Multilayered Connective Tissue Grafting Technique to Improve Aesthetics after Failed GBR: A Clinical Case Report of 16 Months Follow-Up.

OBJECTIVE: This case report describes soft-tissue management after a failed GBR procedure to enhance the soft-tissue quality, quantity, and aesthetic outcomes. Case Presentation. A 38-year-old patient visited the Dental Clinic of the Ospedale Maggiore Policlinico, University of Milan, Milan, Italy, for a chief complaint of unsatisfactory aesthetics of the anterior maxillary area. Dental history disclosed failed preimplant vertical bone augmentation with GBR procedure in the area of the left maxillary central incisor resulting in a severe gingival recession of adjacent teeth and compromised soft-tissue quantity and quality and severe ridge atrophy (class III). Multilayered connective tissue grafting technique, in a two-step mucogingival surgery, was used to cover the gingival recessions, reach even gingival margin, and reconstruct the defect. Frenectomy was done after the second mucogingival surgery to relieve the muscle attachment. A definitive cantilever bridge was placed to restore the left and right maxillary central incisors, and a satisfactory aesthetic outcome was reached. CONCLUSIONS: Multilayered connective tissue grafting technique might be successful in correcting soft-tissue quantity and quality in class III ridge defects.

Expression of MicroRNAs in Periodontal and Peri-Implant Diseases: A Systematic Review and Meta-Analysis.

AIM: The purpose of this review was to evaluate the expression patterns of miRNAs in periodontal and peri-implant diseases, while identifying potential miRNAs with the greatest diagnostic ability as an oral fluid biomarker. MATERIALS AND METHODS: Human and animal studies were included when evaluating expression of miRNAs between health and different forms/stages of diseases, in which microarray and/or real-time polymerase chain reaction (RT-PCR) was carried out to detect fold changes in gene expression. After full-text analysis, 43 articles were considered for a qualitative assessment, and 16 miRNAs were selected to perform meta-analysis. RESULTS: Based on human studies, results showed an overall upregulation of most of the evaluated miRNAs in periodontitis, with miRNA-142-3p and miRNA-146a being the most conclusive on both microarray and RT-PCR values and potentially serving as diagnostic biomarkers for disease activity. Conversely, miR-155 was the only miRNA revealing a statistically significant difference (SSD) (p < 0.05*) in experimental periodontitis models from RT-PCR values. Scarce scientific evidence is available from peri-implant diseases, however, most explored miRNAs in peri-implantitis were downregulated except for miR-145. CONCLUSIONS: Although our results revealed that a distinct differential expression of specific miRNAs can be noted between the state of health and disease, future research remains necessary to explore the functional role of specific miRNAs and their potential as therapeutic targets in periodontal and peri-implant diseases. MeSH Terms: periodontitis, peri-implantitis, epigenomics, microarray analysis, real-time polymerase chain reaction, microRNAs. CLINICAL RELEVANCE: Scientific background: Although most research identified different expression levels of miRNAs in periodontal and peri-implant diseases compared to their counterparts, their actual role in the pathogenesis of these conditions remains unclear. Therefore, we aimed to present a systematic review and meta-analysis on the expression patterns of miRNAs in periodontitis and peri-implantitis, while identifying potential miRNAs with the greatest diagnostic ability as an oral fluid biomarker. PRINCIPAL FINDINGS: In periodontitis-related studies, miRNA-142-3p and miRNA-146a were the most conclusive on both microarray and RT-PCR values. Scarce scientific evidence is available from peri-implant diseases. PRACTICAL IMPLICATIONS: Both miRNA-142-3p and miRNA-146a might serve as future diagnostic biomarkers for disease activity in periodontitis. Yet, future research remains necessary to explore the functional role of specific miRNAs and their potential as therapeutic targets in periodontal and peri-implant diseases.

Role of epigenetics in alveolar bone resorption and regeneration around periodontal and peri-implant tissues.

Periodontitis and peri-implantitis are multifactorial diseases characterized by alveolar bone destruction mediated by the host response to a microbial challenge. Alveolar bone resorption mediated by epigenetics could be one of the mechanisms responsible for this destruction of alveolar bone. The relationship between epigenetic modifications and bone metabolism has been thoroughly investigated in bone remodeling, cancer, and rheumatoid arthritis, but evidence is low regarding the relationship between epigenetic modifications and alveolar bone loss related to periodontal and peri-implant diseases. Therefore, we conducted a review of the pertinent literature based on a priori-formulated focused questions and a screening strategy, in an attempt to comprehend the role of different epigenetic mechanisms in alveolar bone loss and to determine the current state with respect to their possible therapeutic applications in regenerative medicine. The review showed that the roles of DNA methylation, histone modifications, and non-coding RNAs in bone loss have been investigated. The results indicate that epigenetic mechanisms can participate in periodontal and peri-implant alveolar bone breakdown, suggesting their potential as therapeutic targets in alveolar bone regeneration. However, there is still only preliminary information regarding the possible therapeutic utility of these epigenetic mechanisms, suggesting a need for basic and translational research to assess the potential of such mechanisms in promoting alveolar bone regeneration.

Comparison of two soft tissue substitutes for the treatment of gingival recession defects: an animal histological study.

OBJECTIVES: This study aimed to compare two different soft tissue replacement grafts in their ability to treat gingival recession defects and successfully integrate with the surrounding tissues. METHODOLOGY: Nine beagle dogs were included and followed up to 10 weeks. Sites for intervention were allocated to one of the grafting materials investigated. Treatment consisted of coronally advanced flap combined with one of the two soft tissue substitutes on a previous surgically created defect. Materials employed were porcine-derived acellular dermal matrix (ADM) [Novomatrix™ (Test)] and collagen-based matrix (CBM) [Mucograft® (Control)]. Animals were sacrificed at 2, 6, and 10 weeks postoperatively and compared using descriptive histology and histomorphometric outcomes. RESULTS: Macroscopic findings were similar between test and control groups at all intervals. After 10 weeks, both groups demonstrated successful incorporation of the grafting materials without signs of rejection and with comparable tissue integration. The histomorphometric data were similar between groups at 2 weeks; however, the test group provided greater root coverage and increase in tissue thickness than the control at 6- and 10-weeks post surgically. CONCLUSIONS: Both porcine-derived ADM and CBM revealed similar histological outcomes with successful integration and absence of adverse events. Test group provided superior outcomes regarding root coverage and increase in tissue thickness.

Gene Delivery Therapeutics in the Treatment of Periodontitis and Peri-Implantitis: A State of the Art Review.

BACKGROUND: Periodontal disease is a chronic inflammatory condition that affects supporting tissues around teeth, resulting in periodontal tissue breakdown. If left untreated, periodontal disease could have serious consequences; this condition is in fact considered as the primary cause of tooth loss. Being highly prevalent among adults, periodontal disease treatment is receiving increased attention from researchers and clinicians. When this condition occurs around dental implants, the disease is termed peri-implantitis. Periodontal regeneration aims at restoring the destroyed attachment apparatus, in order to improve tooth stability and thus reduce disease progression and subsequent periodontal tissue breakdown. Although many biomaterials have been developed to promote periodontal regeneration, they still have their own set of disadvantages. As a result, regenerative medicine has been employed in the periodontal field, not only to overcome the drawbacks of the conventional biomaterials but also to ensure more predictable regenerative outcomes with minimal complications. Regenerative medicine is considered a part of the research field called tissue engineering/regenerative medicine (TE/RM), a translational field combining cell therapy, biomaterial, biomedical engineering and genetics all with the aim to replace and restore tissues or organs to their normal function using in vitro models for in vivo regeneration. In a tissue, cells are responding to different micro-environmental cues and signaling molecules, these biological factors influence cell differentiation, migration and cell responses. A central part of TE/RM therapy is introducing drugs, genetic materials or proteins to induce specific cellular responses in the cells at the site of tissue repair in order to enhance and improve tissue regeneration. In this review, we present the state of art of gene therapy in the applications of periodontal tissue and peri-implant regeneration. PURPOSE: We aim herein to review the currently available methods for gene therapy, which include the utilization of viral/non-viral vectors and how they might serve as therapeutic potentials in regenerative medicine for periodontal and peri-implant tissues.

Shared decision-making (SDM) in dentistry: A concise narrative review.

OBJECTIVE: The aim of this review was to evaluate the implementation of shared decision-making (SDM) in dentistry and the roles of informed consent and patient decision-making aids (PDAs) as part of this process. MATERIALS AND METHODS: A review of pertinent literature was performed using PubMed and MEDLINE to determine the current position of the application of SDM in dentistry and the influence of informed consent and PDAs on this process. RESULTS: Limited number of published studies on the implementation of SDM in dental practice is available. These studies demonstrated that SDM is influenced by many factors. Informed consent intertwines with the SDM process and begins with providing high quality information to patients and employing PDAs. PDAs have been developed for some dental fields to facilitate the SDM process. CONCLUSIONS: SDM is applied in dentistry and is influenced by many factors. Informed consent is an important part of this process. PDAs in more dental fields need to be further developed, in order to ensure a satisfactory integration of patients in the SDM process.

Comparison of two soft tissue substitutes for the treatment of gingival recession defects: an animal histological study

Abstract Objectives: This study aimed to compare two different soft tissue replacement grafts in their ability to treat gingival recession defects and successfully integrate with the surrounding tissues. Methodology: Nine beagle dogs were included and followed up to 10 weeks. Sites for intervention were allocated to one of the grafting materials investigated. Treatment consisted of coronally advanced flap combined with one of the two soft tissue substitutes on a previous surgically created defect. Materials employed were porcine-derived acellular dermal matrix (ADM) [Novomatrix™ (Test)] and collagen-based matrix (CBM) [Mucograft® (Control)]. Animals were sacrificed at 2, 6, and 10 weeks postoperatively and compared using descriptive histology and histomorphometric outcomes. Results: Macroscopic findings were similar between test and control groups at all intervals. After 10 weeks, both groups demonstrated successful incorporation of the grafting materials without signs of rejection and with comparable tissue integration. The histomorphometric data were similar between groups at 2 weeks; however, the test group provided greater root coverage and increase in tissue thickness than the control at 6- and 10-weeks post surgically. Conclusions: Both porcine-derived ADM and CBM revealed similar histological outcomes with successful integration and absence of adverse events. Test group provided superior outcomes regarding root coverage and increase in tissue thickness.

Micropatterned Scaffolds with Immobilized Growth Factor Genes Regenerate Bone and Periodontal Ligament-Like Tissues.

Periodontal disease destroys supporting structures of teeth. However, tissue engineering strategies offer potential to enhance regeneration. Here, the strategies of patterned topography, spatiotemporally controlled growth factor gene delivery, and cell-based therapy to repair bone-periodontal ligament (PDL) interfaces are combined. Micropatterned scaffolds are fabricated for the ligament regions using polycaprolactone (PCL)/polylactic-co-glycolic acid and combined with amorphous PCL scaffolds for the bone region. Scaffolds are modified using chemical vapor deposition, followed by spatially controlled immobilization of vectors encoding either platelet-derived growth factor-BB or bone morphogenetic protein-7, respectively. The scaffolds are seeded with human cells and delivered to large alveolar bone defects in athymic rats. The effects of dual and single gene delivery with and without micropatterning are assessed after 3, 6, and 9 weeks. Gene delivery results in greater bone formation at three weeks. Micropatterning results in regenerated ligamentous tissues similar to native PDL. The combination results in more mature expression of collagen III and periostin, and with elastic moduli of regenerated tissues that are statistically indistinguishable from those of native tissue, while controls are less stiff than native tissues. Thus, controlled scaffold microtopography combined with localized growth factor gene delivery improves the regeneration of periodontal bone-PDL interfaces.