Comparative in vitro study on biomechanical behavior of zirconia and polyetheretherketone biomaterials exposed to experimental loading conditions in a prototypal simulator.

Zirconia and polyetheretherketone (PEEK) are two biomaterials widely investigated as substitute for metals in oral prosthetic rehabilitation. To achieve a proper biomechanical behavior, the prosthetic biomaterials must ensure a good resistance to loads, as this is a crucial characteristic enabling their use in dental applications. The aim of this study was to investigate differences in the fracture resistance of different biomaterials in an experimental environment: fixed partial dentures (FPDs) screwed in a prototype of biomimetic mandible. 10 Samples of FPDs were allocated in 2 groups (A and B): Group A (n=5) involved FPDs in zirconia-ceramic, and Group B (n=5) involved FPDs in PEEK-composite. The samples were loaded by means of a three-point bending mechanical test, and the load to fracture has been evaluated generating a point-by-point graphics (speed/load and time/deformation). The samples were further analyzed by micro-computed tomography (micro-CT) and described under experimental loading conditions. Zirconia-ceramic FDPs were the samples reporting the worst results, showing a lower value of vertical displacement with respect to PEEK-based samples. The micro-CT results have further confirmed the preliminary results previously described. This in vitro study aims to give analytic data on the reliability of PEEK as a reliable and strong biomaterial for prosthetic treatments.

Critical Overview on Pure Chitosan-based Scaffolds for Bone Tissue Engineering: Clinical insights in Dentistry.

Bone Tissue Engineering (BTE) is a field of regenerative medicine continuously improving, thanks to the development of new biomaterials used as grafts or scaffolds for repairing bone defects. In recent years, chitosan, a natural biopolymer extracted mainly from crustacean shells, has demonstrated unique and desirable characteristics for BTE applications, such as: biocompatibility, biodegradability, and osteoconductive behavior. Additionally, the presence of numerous active amine groups in its chemical structure allows it to be easily modified. Data suggest that chitosan scaffolds are highly biomimetic, and show an interesting bioactivity, and antibacterial behavior. We have demonstrated, in a critical overview, how chitosan-based scaffolds may hold great interest for BTE applications in medical and dental applications. Future research should be focused on the use of chitosan-scaffolds combined with other biomaterials or bioactive molecules, to increase their overall regenerative potential, also in critical-sized defects. In conclusion, chitosan can be considered a promising biomaterial in BTE and clinical dentistry.

Influence of crestal and sub-crestal implant position on development of peri-implant diseases: a 5-year retrospective analysis.

OBJECTIVES: The aim of the present study was to evaluate the influence of crestal and subcrestal implant position on development of peri-implant diseases. MATERIALS AND METHODS: The study was designed as a retrospective clinical and radiographic analysis. Implant-supported fixed dental prostheses were allocated in two groups: with the shoulder (i) placed in sub-crestal level and (ii) placed at bone level. For each patient, the following clinical variables were assessed: FMPS, FMBS, PlI, BOP, and PD. After prothesis delivery, an intraoral radiograph was obtained; this exam was performed also at 5 years of observation period. RESULTS: No statistically significant difference was found in terms of FMPS and FMBS at baseline and after 5 years follow-up (P < 0.05). A statistically significant difference was assessed between PD of control group and test group (P = 0.042). Patient-based analysis showed a 25.6% of peri-implant mucositis and 32.6% of peri-implantitis for implants placed with the shoulder in crestal position, while for implants inserted in sub-crestal position the percentage of peri-implant-mucositis and peri-implantitis were 19%; no statistically significant difference was found between groups after 5 years (P < 0.05). CONCLUSIONS: Within the limitation of the present study, the clinical and radiographic outcomes showed that the percentage of peri-implant mucositis and peri-implantitis was not statistically significant for both groups after 5 years follow-up. CLINICAL RELEVANCE: The outcomes of present study clinically demonstrated that a deep position of implant shoulder did not provide any benefits. On the contrary, it may be considered a possible risk indicator for implant diseases.

The role of cognitive and non-cognitive factors in dental anxiety: A mediation model.

Dental anxiety is a crucial problem for dentistry because it may represent a significant risk to oral health. Different factors, whether non-cognitive (e.g., traumatic dental events) or cognitive (e.g., the patient's subjective perceptions), may cause dental anxiety. However, previous studies have assessed these factors as independent predictors of dental anxiety, without providing any exploration of potential mediational pathways. The current study assessed the role of certain cognitive dimensions (i.e., the dentist's perceived professionalism and communicational attitudes, and the patient's perceived lack of control) as mediators between traumatic dental events and dental anxiety. The sample comprised 253 patients who had accessed a public university hospital dental surgery. The mediation analysis used a structural equation modeling. Traumatic dental events were positively associated with dental anxiety but, among the cognitive factors, only lack of control was. Furthermore, lack of control mediated the relationship between traumatic dental events and dental anxiety, although this mediation was only partial. This study sheds light on the mechanisms through which non-cognitive and cognitive factors may affect dental anxiety. The clinical implications for dental practice, in terms of improving the psychological well-being of patients, are discussed.

Use of injectable platelet-rich fibrin in the treatment of plasma cell mucositis of the oral cavity refractory to corticosteroid therapy: A case report.

Plasma cell mucositis (PCM) is a rare benign disease affecting adults characterized by an erythematous mucosa, an epithelial hyperplasia, and a dense submucosal infiltration of mainly mature plasma cells. PCM has been treated with topical, intralesional, and systemic corticosteroids, antibiotics, and topical cyclosporin with unreliable results and questionable benefits. Here, we present a case of PCM, refractory to previous treatments, treated with i-PRF (injectable platelet-rich fibrin) injections. The infiltrations were performed once a week for 2 months. There were no adverse reactions to the treatment. The pain gradually reduced until the score of zero at the fourth infiltration, and the patient remained free of pain during the whole study period. Clinically, we did not obtain a complete healing of the lesion, but a reduced perilesional inflammatory infiltrate was observed at a distance. Therefore, we can conclude that i-PRF has been effective in the management of pain in PMC but does not result in complete healing of the disease.

Prosthetic Rehabilitation of the Posterior Atrophic Maxilla, Short (≤6 mm) or Long (≥10 mm) Dental Implants? A Systematic Review, Meta-analysis, and Trial Sequential Analysis: Naples Consensus Report Working Group A.

PURPOSE: To compare the clinical and patient-reported outcomes of ≤6-mm implants with those of ≥10-mm implants placed after both lateral and transcrestal sinus floor elevation. MATERIALS AND METHODS: Using PubMed (MEDLINE), EMBASE, and Cochrane, a literature search for randomized controlled trials was performed. All the outcome variables were evaluated through a quantitative meta-analysis, and the influence of other clinical covariates were determined with a metaregression. For the survival outcomes, trial sequential analysis (TSA) was performed to adjust results for type I and II errors and to analyze the power of the available evidence. RESULTS: After full-text reading, 12 studies were included in the analyses. No statistically significant difference was found after 3 years between the 2 study groups (P = 0.36). Short implants displayed fewer biological complications (P = 0.05), less marginal bone loss (MBL) from implant placement (P < 0.01), and reduced surgical time and treatment cost. However, long implants showed a statistically significant smaller number of prosthetic complications (P = 0.03). TSA confirmed the results of the meta-analysis, revealing that additional studies are needed due to low statistical power of the available evidence. CONCLUSION: The placement of short implants is a predictable option in treating patients with maxillary atrophy up to a 3-year follow-up. Studies with a longer observational period are needed to study the long-term performance of these implants.

Use of platelet-rich fibrin in regenerative dentistry: a systematic review.

OBJECTIVES: Research across many fields of medicine now points towards the clinical advantages of combining regenerative procedures with platelet-rich fibrin (PRF). This systematic review aimed to gather the extensive number of articles published to date on PRF in the dental field to better understand the clinical procedures where PRF may be utilized to enhance tissue/bone formation. MATERIALS AND METHODS: Manuscripts were searched systematically until May 2016 and separated into the following categories: intrabony and furcation defect regeneration, extraction socket management, sinus lifting procedures, gingival recession treatment, and guided bone regeneration (GBR) including horizontal/vertical bone augmentation procedures. Only human randomized clinical trials were included for assessment. RESULTS: In total, 35 articles were selected and divided accordingly (kappa = 0.94). Overall, the use of PRF has been most investigated in periodontology for the treatment of periodontal intrabony defects and gingival recessions where the majority of studies have demonstrated favorable results in soft tissue management and repair. Little to no randomized clinical trials were found for extraction socket management although PRF has been shown to significantly decrease by tenfold dry sockets of third molars. Very little to no data was available directly investigating the effects of PRF on new bone formation in GBR, horizontal/vertical bone augmentation procedures, treatment of peri-implantitis, and sinus lifting procedures. CONCLUSIONS: Much investigation now supports the use of PRF for periodontal and soft tissue repair. Despite this, there remains a lack of well-conducted studies demonstrating convincingly the role of PRF during hard tissue bone regeneration. Future human randomized clinical studies evaluating the use of PRF on bone formation thus remain necessary. CLINICAL RELEVANCE: PRF was shown to improve soft tissue generation and limit dimensional changes post-extraction, with little available data to date supporting its use in GBR.

Safe New Approach to the Lingual Flap Management in Mandibular Augmentation Procedures: The Digitoclastic Technique.

PURPOSE: This article describes the digitoclastic technique, an innovative procedure for coronal displacement of the lingual flap. The new technique has the potential to obtain primary flap closure without surgical risks to the anatomical structures on the lingual side of the mandible. MATERIALS AND METHODS: Reconstruction of an atrophic mandible with guided tissue regeneration (guided bone regeneration) and implant placement is described, using the digitoclastic technique to displace the lingual flap coronally. RESULTS: Coronal flap displacement was sufficient to obtain complete passive coverage of the grafted area. No bleeding or neurosensory complications were recorded, and no membrane exposure occurred. CONCLUSIONS: The digitoclastic technique reduces the risk of damage to the lingual nerve and minimizes the amount of bleeding during surgery, allowing progressive and controlled retraction of the flap until the desired detachment is achieved.

The Use of Piezosurgery in Genioplasty.

The aim of this study was to compare the postoperative complications during genioplasty using piezosurgery devices or traditional rotating drills. Forty patients underwent genioplasty to solve their chin anomalies. This study showed that, using piezosurgery, pain and swelling were reduced compared to the traditional technique in the immediate postoperative period of healing (within 15 days). Paresthesia was observed in all patients up to 15th postoperative day, independently of the used surgical technique, but at the sixth postoperative month it was completely absent.

Platelet-Rich Plasma Increases Growth and Motility of Adipose Tissue-Derived Mesenchymal Stem Cells and Controls Adipocyte Secretory Function.

Adipose tissue-derived mesenchymal stem cells (Ad-MSC) and platelet derivatives have been used alone or in combination to achieve regeneration of injured tissues. We have tested the effect of platelet-rich plasma (PRP) on Ad-MSC and adipocyte function. PRP increased Ad-MSC viability, proliferation rate and G1-S cell cycle progression, by at least 7-, 2-, and 2.2-fold, respectively, and reduced caspase 3 cleavage. Higher PRP concentrations or PRPs derived from individuals with higher platelet counts were more effective in increasing Ad-MSC growth. PRP also accelerated cell migration by at least 1.5-fold. However, PRP did not significantly affect mature adipocyte viability, differentiation and expression levels of PPAR-γ and AP-2 mRNAs, while it increased leptin production by 3.5-fold. Interestingly, PRP treatment of mature adipocytes also enhanced the release of Interleukin (IL)-6, IL-8, IL-10, Interferon-γ, and Vascular Endothelial Growth Factor. Thus, data are consistent with a stimulatory effect of platelet derivatives on Ad-MSC growth and motility. Moreover, PRP did not reduce mature adipocyte survival and increased the release of pro-angiogenic factors, which may facilitate tissue regeneration processes.

Autologous fat grafting in facial volumetric restoration.

The authors reported their surgical experience about structural fat grafting in the management of facial volumetric deficit. The purpose of this study was to assess the real indications, cosmetic results, complications, and global patient satisfaction of the Coleman technique in redefining facial contours in congenital and postoperative deformities. A retrospective analysis of 32 patients grafted according to Coleman's technique was performed, and the long-term outcomes and patient satisfaction were evaluated. The mean postoperative clinical follow-up was 14 months. The morphological changes were analyzed by comparing the photographic presurgical facial contour and the postoperative correction of soft tissue defects. All consecutive cases reported showed a progressive fat resorption for 3 months after surgery and its stable integration only after this period. Best results were performed in the treatment of genetically determined syndromes, such as the Franceschetti and Romberg syndromes. The authors suggest this surgical technique also for the treatment of unaesthetic cutaneous abscess cavity after incision and drainage. Unsatisfactory outcomes were obtained in the treatment of the posttraumatic facial scar, which needed more surgical procedures.

Technical and biological complications related to crown to implant ratio: a systematic review.

AIM: To review the occurrence of prosthetic failure and biological complications with respect to the crown to implant (C/I) ratio. METHODS: Accurate search was made on the subject C/I ratio with the following criteria: (1) studies on humans with data on prosthetic failure and/or biological complications related to C/I ratio; (2) partial edentulous patients; (3) randomized clinical trials, prospective, longitudinal, retrospective, and multicenter studies with a minimum of 48 months mean follow-up; (4) language: English; (5) radiographic measurements by peri-apical x-ray; (6) implant material: titanium; and (7) no implant type selection was applied. RESULTS: Six articles were considered eligible for full-text analysis. Unfavorable C/I ratio can be considered a potential risk factor for single crown and abutment loosening (C/I ratio ≥ 1.46) and abutment fractures in posterior areas (C/I ratio ≥ 2.01). CONCLUSIONS: Despite the limited data, high C/I ratio may be related to some prosthetic failures. Unfavorable C/I ratio does not affect biological complications and implant failure.

Two neglected biologic risk factors in bone grafting and implantology: high low-density lipoprotein cholesterol and low serum vitamin D.

Following a failure of a bone graft or an implant placement, the hypothesis of a biological abnormality is rarely considered as a possible cause. A systematic search of peer-reviewed literature for dyslipidemia or vitamin D deficiency may explain this lack of consideration. Excess low-density lipoprotein cholesterol (dyslipidemia) is responsible for a slower bone metabolism or lower dental implant osseointegration. In addition, vitamin D is a key factor for linking innate and adaptive immunity. Both of these factors are compromised under the conditions of vitamin D deficiency. Therefore, vitamin D deficiency slows implant osseointegration and increases the risk of graft infection. Vitamin D is also involved in immune function and therefore allergic reactions.

Effectiveness of Autologous Platelet Concentrates in the Sinus Lift Surgery: Findings from Systematic Reviews and Meta-Analyses.

Maxillary sinus augmentation is one of the most predictable procedures for the rehabilitation of the posterior maxilla. The current overview aimed to summarize the findings provided by systematic reviews (SRs) and meta-analyses on the effectiveness of autologous platelet concentrates (APCs) in sinus lift and to assess the methodological quality of the included SRs. Three electronic databases have been explored. SRs and meta-analyses addressing the effectiveness of APCs in sinus lift technique were included. Clinical, radiographic and histomorphometric findings were considered for APCs as solely grafting materials and APCs in combination with biomaterials. Outcomes were implant survival rate (ISR), implant stability (IS), implant failure (IF), postoperative complications, histomorphometric findings, radiographic bone gain, bone volume and bone density. The methodological quality of the included SRs was assessed using the updated version of "A Measurement Tool to Assess Systematic Review" (AMSTAR-2). Thirty SRs were included. The methodological quality of the included reviews ranged from critically low (3 studies) to high (9 studies). The included SRs showed favorable clinical outcomes, short-term new bone formation and no biological complications when APCs were used both as solely graft material or in combination with other biomaterials. However, no significant additional effects in the long-term period were observed. APCs did not add any further positive effects compared to the physiological healing derived by the natural blood clot. The current overview of SRs highlighted the need for high-quality SRs evaluating the role of APCs in sinus lift though network meta-analyses, in order to identify the most powerful material for sinus lift augmentation. The use of APCs improves the healing of soft tissues and the postoperative quality of life in the short-term period. Thus, its application can be recommended.

The Effects of Ultrasonic Scaling and Air-Abrasive Powders on the Topography of Implant Surfaces: Scanning Electron Analysis and In Vitro Study.

OBJECTIVES: This in vitro study aimed to investigate the impact of bicarbonate air-abrasive powders and ultrasonic scaling with stainless steel tips on the micro- and nanotopography and roughness of three different implant-abutment junction titanium surfaces. MATERIALS AND METHODS: Three types of sterile and decontaminated titanium surfaces (RS, UTM, XA) were used for analysis. Nine disks per surface type were subjected to micro- and nanotopography analysis, scanning electron microscopy (SEM), roughness analysis, and fibroblast cultivation. Ultrasonic debridement and air polishing were performed on the surfaces. Human dermal fibroblasts were cultured on the surfaces for 5 days. STATISTICAL ANALYSIS: Data analysis adhered to ISO 25178 standards for surface texture assessment. SEM micrographs were used to reconstruct areas for extracting roughness parameters. Excel and Mex 6.0 software were utilized for quantitative and stereoscopic analysis. RESULTS: The study found varying effects on surface roughness posttreatment. RS Disco samples exhibited higher surface roughness compared with UTM and XA samples, both in average and nanoscale roughness. Decontamination led to increased surface roughness for all samples, particularly RS Disco. Fibroblast growth tests revealed enhanced cell network formation on decontaminated discs, possibly due to increased nanoscale roughness or the presence of bicarbonate salts. CONCLUSION: The study underscores the complex interplay between surface topography, microbial biofilm, and treatment efficacy in peri-implant disease management. While smoother surfaces may resist biofilm accumulation, increased nanoscale roughness postdecontamination can enhance fibroblast attachment and soft tissue integration. This dichotomy highlights the need for tailored treatment protocols that consider material-specific factors, emphasizing that successful implant therapy should balance microbial control with conducive surface characteristics for long-term osseointegration and soft tissue stability.

Periodontal care as a fundamental step for an active and healthy ageing.

In the industrialized part of the world, an increasing number of people live the old age without too many restrictions due to illness or physiological impairment. This group is known as the young elderly. On the contrary, a consistent part of seniors develops a greater number of medical conditions and become more and more dependent, these are the old elderly. The first cause of tooth lost in industrialized word is periodontitis that generally strikes people older than 40 years and determines serious detriment of the stomatognatic organ. Smoking and stress are risk factors for periodontitis that are common and shared between young, adult, and older age. Diabetes mellitus, obesity, and osteoporosis are very frequent pathological situations in older age. They have been identified as cofactors in the progression of periodontitis. Many dental associations recognize the importance of continued research on oral fluids diagnostics and welcome the development of rapid point-of-care tests providing accurate measurements of clinically validated biomarkers. At present, well-studied molecules associated with host response factors and with derived tissue destruction mediators have been proposed as diagnostic biomarkers for periodontitis detected in the oral fluids.

Soft and hard tissues healing at immediate transmucosal implants placed into molar extraction sites with collagen membrane uncovered: a 12-month prospective study.

PURPOSE: To assess soft and hard tissues healing at immediate transmucosal implants placed into maxillary molar region with collagen membranes uncovered. MATERIALS AND METHODS: Twenty subjects received 20 immediate transmucosal implants placed in maxillary molar extraction sockets. Periimplant marginal defects were treated according to the principles of guided bone regeneration by means of deproteinized bovine bone mineral particles in conjunction with collagen membrane. Flaps were repositioned and sutured, allowing nonsubmerged, transmucosal soft tissues healing. The collagen membranes adapted around implant neck were uncovered. RESULTS: No implants were lost during the 1-year observation period yielding a survival rate of 100%. No postsurgical wound healing complications were observed. No degranulation of grafting material was reported. CONCLUSIONS: The results of this 12-month prospective study showed that the exposure of collagen membrane at time of the flap suturing does not represent a limitation for the soft and hard tissues healing at immediate transmucosal implants placed into maxillary molar extraction sites.

A comparison of bovine bone and hydroxyapatite scaffolds during initial bone regeneration: an in vitro evaluation.

OBJECTIVES: To evaluate the different behavior of 3-dimensional biomaterial scaffolds-Bovine Bone (BB; Bio-Oss) and Hydroxyapatite (HA; ENGIpore)-during initial bone healing and development. MATERIALS AND METHODS: Human dental papilla stem cells (hDPaSCs) were selected with FACsorter cytofluorimetric analysis, cultured with osteogenic medium, and analyzed with Alizarin red stained after differentiation. The obtained osteoblast-like cells (OCs) were cultured with BB and HA. alkaline phosphatase (ALP), OC, MEPE, and runt-related transcription factor 2 (RUNX2) expression markers were investigated performing Western blot and reverse transcription-polymerase chain reaction (RT-PCR) analysis. After 40 days, samples were analyzed by light and electron microscopy. RESULTS: All the samples showed high in vitro biocompatibility and qualitative differences of OCs adhesion. RT-PCR and Western blot data exhibited similar marker rate, but ALP, OC, MEPE, and RUNX2expression, during initial healing and bone regeneration phase, was higher and faster in human dental papilla onto BB than in HA scaffolds. In biomaterials growth, RUNX2 seems to play an important role as a key regulator in human OCs from dental papilla bone development. CONCLUSION: Different surface BB scaffold characteristics seem to play a critical role in OCs differentiation showing different time of bone regeneration morphological characteristics as well as higher and faster levels of all observed markers.

Advances in Dental Implants, Tissue Engineering and Prosthetic Materials.

Scientific research has achieved numerous milestones in the field of materials applied to medicine for biomedical prosthetics [...].

Unlocking the Potential of Dental-Derived Mesenchymal Stem Cells in Regenerative Medicine.

Over the past few decades, life expectancy has been increasing in several countries [...].