Leukocytes within Autologous Blood Concentrates Have No Impact on the Growth and Proliferation of Human Primary Osteoblasts: An In Vitro Study.

Platelet-rich fibrin (PRF) is a widely used autologous blood concentrate in regenerative medicine. This study aimed to characterize the cellular composition and distribution of different PRF matrices generated by high (710 g) and low (44 g) relative centrifugal forces (RCFs) and to analyze their bioactivity on human primary osteoblasts (pOBs). PRF was separated into upper layer (UL) and buffy coat (BC) fractions, and their cellular contents were assessed using histological and immunohistochemical staining. The release of platelet-derived growth factor (PDGF) and transforming growth factor (TGF-ß) was quantified using an ELISA. Indirect PRF treatment on pOBs was performed to evaluate cell viability and morphology. A histological analysis revealed higher quantities of leukocytes and platelets in the low-RCF PRF. TGF-ß release was significantly higher in the low-RCF PRF compared to the high-RCF PRF. All PRF fractions promoted pOB proliferation regardless of the centrifugation protocol used. The low-RCF PRF showed higher TGF-ß levels than the high-RCF PRF. These findings contribute to understanding the cellular mechanisms of PRF and provide insights into optimizing PRF protocols for bone regeneration, advancing regenerative medicine, and improving patient outcomes.

Evaluation of marginal and internal adaptation of veneers generated by the guided prosthetic tooth preparation system.

OBJECTIVE: This in vitro study aimed to assess and contrast the marginal and internal adaptation of all-ceramic prefabricated veneers manufactured via the FirstFit guided tooth preparation system against all-ceramic veneers produced using the chairside Computer-Aided Design/Computer Aided Manufacture (CAD/CAM) system following identical guided preparation protocols. MATERIALS AND METHODS: Two main groups were included, with 16 lithium disilicate veneers per group. Four typodonts were used for the test (FirstFit) and control CAD/CAM groups. Intraoral scans created master casts and preparation guides. Guides performed preparations on typodont teeth (two central incisors and two lateral incisors). Prepared teeth were scanned (CEREC Omnicam) to design and mill CAD/CAM veneers. Marginal gap thickness and cement space thickness were measured using light microscopy at four locations: marginal, cervical internal, middle internal, and incisal internal. RESULTS: No significant difference existed between groups for marginal adaptation (p = 0.058) or incisal internal adaptation (p = 0.076). The control group had significantly lower values for middle internal adaptation (p = 0.023) and cervical internal adaptation (p = 0.019). CONCLUSIONS: Guided preparation evaluation showed no significant differences in marginal or incisal internal adaptation. The CAD/CAM group had significantly lower middle and cervical internal adaptation values.

Effectiveness of Oroantral Communication Closure Using Solid Platelet-Rich Fibrin Compared to a Conventional Treatment Approach: A Randomized Clinical Trial.

This study aimed to compare the effectiveness of platelet-rich fibrin clot (PRF) and conventional oroantral communication (OAC) repair techniques following tooth extractions from the maxilla. The study involved 22 patients, divided into 2 groups: a study group treated with PRF and a control group undergoing conventional OAC repair. The primary outcome measured was the effectiveness of OAC closure, with pain intensity and postoperative complications as secondary outcomes. Cone-beam computed tomography (CBCT) was used to evaluate post-extraction bone regeneration. Pain was assessed using the Visual Analogue Scale (VAS) on days 0, 1, 7, and 14 postoperatively. The results showed that the PRF group experienced a significant decrease in pain within the first 24 hours and after 7 days (P < .0001; P < .05). In contrast, complications were reported in 45.45% of patients in the conventional repair group and 18.18% in the A-PRF group. Three months postsurgery, CBCT revealed appreciable bone healing in both groups, with no significant difference (P > .05). In conclusion, the study suggests that A-PRF treatment for OACs resulted in fewer complications and quicker pain reduction than traditional repair methods, making it a promising alternative for managing OACs. However, future studies are needed to confirm these findings and establish the full therapeutic potential of PRF.

Dental autotransplantation: a viable solution for preserving oral health and function.

DESIGN: An umbrella review of systematic reviews and meta-analyses on dental autotransplantation (DAT). AIM: To provide a comprehensive overview of the current state of knowledge on prognostic factors, outcomes, and complications of DAT by synthesizing the evidence. METHODS: A comprehensive search of six databases was conducted for systematic reviews and meta-analyses published up to June 30, 2022. Two authors independently performed study selection, data extraction, and quality assessment using the AMSTAR 2 tool. Raw data from primary studies were analyzed using a random effects meta-analysis, and meta-regression was performed to investigate the effect of open and closed apices on the outcomes. RESULTS: Ten systematic reviews, of which nine included meta-analyses, were examined. The overall success rate of the studies was 89.4%, and the survival rate was 96.1%. The main complications were ankylosis (4.6%) and root resorption (7.4%). The analysis showed that a closed apex increased the proportion of ankylosis, resorption, and reduced survival but had no effect on success. The quality of the systematic reviews included varied, with 20% scoring moderate, 60% scoring low, and 20% scoring critically low on the AMSTAR 2 scale. CONCLUSIONS: Dental implant therapy is a reliable solution for replacing lost or damaged teeth, with high success and survival rates. However, it is a procedure that requires precision and attention to detail, along with careful selection of suitable candidates, comprehensive planning, and consideration of factors that may impact outcomes. To improve results and reduce potential complications, it is essential to establish standard clinical guidelines and conduct further extensive research.

What are the emerging trends in dental composite materials in permanent teeth with occlusal cavities: self-adhesive vs traditional?

DESIGN: The research is a systematic review and meta-analysis of randomized controlled trials (RCTs). AIM: The study aimed to compare the clinical outcomes of self-adhesive flowable composite resins (SAFCs) versus conventional flowable composite resins (FCs) used in occlusal cavity restorations in permanent teeth. METHODS: This research included a search for RCTs. Multiple databases were systematically searched for RCTs with a minimum 1-year follow-up comparing SAFCs to FCs. Outcomes evaluated were retention, secondary caries, marginal adaptation, marginal discoloration, and postoperative sensitivity based on modified USPHS criteria. Risk of bias was assessed using Cochrane RoB 2 tool. Random effects meta-analyses were conducted where applicable. Certainty of evidence was rated using GRADE approach. RESULTS: Five RCTs (four parallel and one split mouth) comprising 138 patients were included. During 1- and 2-year recalls, there were generally no significant differences in clinical performance between SAFCs and FCs. However, FCs applied using the etch-and-rinse technique demonstrated statistically better marginal adaptation at 2 years (3 studies, RR 3.21, 95% CI 1.50-6.83) and marginal discoloration (4 studies, RR 3.40, 95% CI 1.10-10.48). The overall quality of evidence ranged from low to moderate. CONCLUSIONS: SAFCs showed comparable short-term outcomes to FCs in treating occlusal cavities. Further high-quality RCTs with longer follow-up are warranted to confirm long-term performance of SAFCs. Use of separate enamel etching may improve marginal adaptation and discoloration with FCs.

Antimicrobial effect of platelet-rich fibrin: A systematic review of in vitro evidence-based studies.

This systematic review (SR) aimed to evaluate the antimicrobial potential of different types of platelet-rich fibrin (PRF) often used in regenerative treatments. An electronic search was performed in four databases and in Gray literature for articles published until January, 2023. The eligibility criteria comprised in vitro studies that evaluated the antimicrobial effect of different types of PRF. For the analysis of the risk of bias within studies, the modified OHAT (Office of Health Assessment and Translation) tool was used. For the evaluation of the results, a qualitative critical analysis was carried out in the synthesis of the results of the primary studies. Sixteen studies published between 2013 and 2021 were included in this SR. The antimicrobial effects of PRF variations (PRF, injectable PRF [I-PRF], PRF with silver nanoparticles [agNP-PRF], and horizontal PRF [H-PRF]), were analyzed against 16 types of bacteria from the oral, periodontal, and endodontic environments. All types of PRF showed significant antimicrobial action, with the antibacterial efficacy being more expressive than the fungal one. The I-PRF, H-PRF, and agNP-PRF subtypes improve antimicrobial activity. According to the OHAT analysis, no study was classified as having a high risk of bias. Evidence suggests that PRF variations have significant antimicrobial activity, with bacterial action being greater than fungal. Evolutions such as I-PRF, H-PRF, and agNP-PRF improve antimicrobial activity. Future studies analyzing the clinical effect of these platelets are fundamental. This SR was registered in INPLASY under number INPLASY202340016.

Effects of platelet-rich fibrin produced by three centrifugation protocols on bone neoformation in defects created in rat calvaria.

This study evaluated the potential of Leukocyte-platelet-rich fibrin (L-PRF; fixed angle centrifugation protocol), Advanced-platelet-rich fibrin (A-PRF; low-speed fixed angle centrifugation protocol), and Horizontal-platelet-rich fibrin (H-PRF; horizontal centrifugation protocol) in bone neoformation in critical size defects (CSDs) in rat calvaria. Thirty-two rats were divided into groups: Control (C), L-PRF, A-PRF, and H-PRF. 5 mm diameter CSDs were created in the animals' calvaria. Defects from group Control (C) were filled with blood clots, while defects from groups L-PRF, A-PRF, and H-PRF were filled with respective platelet-rich fibrin (PRF) membranes. L-PRF, A-PRF, and H-PRF were prepared from animal blood collection and specific centrifugation protocols. At 14 and 30 days, calcein (CA) and alizarin (AL) injections were performed, respectively. Animals were euthanized at 35 days. Microtomographic, laser confocal microscopy, and histomorphometric analyzes were performed. Data were statistically analyzed (ANOVA, Tukey, p < .05). L-PRF, A-PRF, and H-PRF groups showed higher values of bone volume (BV), newly formed bone area (NFBA), and precipitation of CA and AL than the C group (p < .05). The H-PRF group showed higher values of BV, number of trabeculae (Tb. N), NFBA, and higher precipitation of AL than the A-PRF and L-PRF groups (p < .05). Therefore, it can be concluded that: i) L-PRF, A-PRF, and H-PRF potentiate bone neoformation in CSDs in rat calvaria; ii) H-PRF demonstrated more biological potential for bone healing.

After tooth loss, the alveolar bone (which supports the teeth) undergoes a natural process called bone remodeling, which can lead to significant decreases in bone height and thickness over time. Faced with the need to replace missing teeth, especially when it comes to dental implants, the lack of supporting tissues can compromise their correct positioning, leading to negative impacts on the success and longevity of the treatment. Therefore, over the years, several materials and procedures have been proposed to preserve and regenerate oral tissues. Leukocyte-platelet-rich fibrin (L-PRF) consists of a membrane obtained by centrifuging the patient's blood in a fixed-angle centrifuge, allowing cells to be available to stimulate tissue regeneration directly at the place of action. Several reports demonstrate high potential in stimulating the formation of new tissues using L-PRF. In recent years, new protocols have been proposed to increase cell concentration and improve the regenerative potential of these membranes, changing the speed and time of centrifugation and introducing horizontal centrifugation. However, there still needs to be concrete evidence of the superiority of the new protocols in relation to the original protocol. In this study, we evaluated the healing of defects created in rat calvaria using platelet aggregates obtained through different centrifugation protocols. Within the limits of this study, it can be concluded that platelet aggregates improve bone healing, and horizontal centrifugation promotes more satisfactory results compared to fixed-angle protocols.

Harnessing the Power of PAOO and Invisalign: An Interdisciplinary Approach to Orthodontic Care.

The present article explores the benefits of combining periodontally accelerated osteogenic orthodontics (PAOO) with Invisalign for optimal orthodontic treatment outcomes. PAOO is an interdisciplinary dental technique that minimizes complications and accelerates tooth movement while enhancing various orthodontic treatments. In conjunction with Invisalign, PAOO provides a discreet and comfortable solution for patients seeking to improve their smile. The study presents two challenging cases successfully treated using this combined approach, emphasizing the technique's potential to reduce treatment times and improve orthodontic outcomes. The interdisciplinary approach of PAOO ensures long-term success and stability by preserving periodontal structures and addressing potential bony defects. By incorporating bone grafting materials, PAOO helps prevent common concerns in traditional orthodontic treatments, such as bony defects and gingival recession. Furthermore, the combination with Invisalign offers a more aesthetically pleasing and comfortable treatment experience, allowing patients to maintain their self-esteem and confidence throughout the treatment. Despite the potential advantages, dental professionals must manage patient expectations and address potential complications to ensure the best possible results. Overall, the integration of PAOO and Invisalign demonstrates a viable alternative for patients who do not want to proceed with orthognathic surgery, enhancing patient satisfaction and overall treatment outcomes.

The Interplay of Raloxifene and Sonochemical Bio-Oss in Early Maxillary Sinus Bone Regeneration: A Histological and Immunohistochemical Analysis in Rabbits.

The study aimed to assess the efficacy of using Raloxifene with ultrasonic processing to enhance Bio-Oss®, a bone graft substitute, for maxillary sinus bone height reconstruction. A total of 24 rabbit maxillary sinuses were distributed into three groups, each receiving different treatments: Bio-Oss® only, sonicated Bio-Oss, and sonicated Bio-Oss® with Raloxifene. Surgical procedures and subsequent histomorphometric and immunohistochemistry analyses were conducted to evaluate the bone formation, connective tissue, and remaining biomaterial, as well as the osteoblastic differentiation and maturation of collagen fibers. Results indicated that the sonicated Bio-Oss® and Bio-Oss® groups showed similar histological behavior and bone formation, but the Raloxifene group displayed inflammatory infiltrate, low bone formation, and disorganized connective tissue. The statistical analysis confirmed significant differences between the groups in terms of bone formation, connective tissue, and remaining biomaterial. In conclusion, the study found that while sonicated Bio-Oss® performed comparably to Bio-Oss® alone, the addition of Raloxifene led to an unexpected delay in bone repair. The findings stress the importance of histological evaluation for accurate bone repair assessment and the necessity for further investigation into the local application of Raloxifene. Future research may focus on optimizing bone substitutes with growth factors to improve bone repair.

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.

Is it possible to decrease the occurrence of dental implant failures through the use of preventative antibiotics?

DESIGN: The research was a randomized placebo-controlled clinical trial evaluating the use of clindamycin as a preoperative medication to prevent the dental implant. AIM: The purpose of the study was to assess if giving a single dose of 600 mg oral clindamycin 1 h before a conventional dental implant procedure could reduce the risk of early implant failure and post-surgical complications in healthy adults. METHODS: A clinical trial was conducted with ethical standards, utilizing a randomized, double-blind, placebo-controlled approach. Healthy adults who required a single oral implant and had no previous surgical site infection or need for bone grafting were enrolled. Before surgery, participants were given either oral clindamycin or placebo at random. A single surgeon performed all operations, and patients were observed by a trained professional on multiple postoperative days. The study considered early dental implant failure as the loss or removal of an implant. Clinical, radiological, and surgical data were analyzed statistically to identify group differences. The number of subjects needed to treat, or harm, was calculated. RESULTS: The research involved two groups of 31 patients each: the control group and the clindamycin group. Two patients in the clindamycin group experienced implant failures (NNH = 15, p = 0.246). Three patients in the study had postoperative infections; two of them were from the placebo group, while one from the clindamycin group had an unsuccessful treatment outcome. The relative risk was 0.5, with a CI of 0.05-5.23 and an absolute risk reduction of 0.03. The confidence interval was -0.07-0.13, and the NNT was 31, with a CI of 7.2-∞ and p = 0.5. In addition, only one patient treated with clindamycin reported gastrointestinal disturbances and diarrhea. CONCLUSIONS: There is no conclusive evidence to suggest that administering clindamycin prior to oral implant surgery in healthy adults reduces the risk of implant failure or post-surgical complications.

Does implant location influence the risk of peri-implantitis?

Peri-implantitis is characterized by nonreversible and progressive loss of supporting bone and is associated with bleeding and/or suppuration on probing. Peri-implant disease is considered as the main etiologic factor related to implant failure. Peri-implant disease has a pathogenesis similar to that of periodontal disease, both being triggered by an inflammatory response to the biofilm accumulation. Although the prevalence of peri-implantitis has been evaluated by several clinical studies with different follow-ups, there are currently little data on the impact of implant location and the prevalence of peri-implantitis. The aim of this review, therefore, was to summarize the evidence concerning the prevalence of peri-implantitis in relation to implant location and associated risk predictors. Even though most studies evaluating the prevalence of peri-implantitis in relation to implant location are cross-sectional or retrospective, they suggest that the occurrence of peri-implantitis is most prevalent in the anterior regions of the maxilla and mandible. Moreover, it seems that there is a higher prevalence of peri-implantitis in the maxilla than in the mandible.

Comparison of the effects of platelet concentrates produced by high and low-speed centrifugation protocols on the healing of critical-size defects in rat calvaria: a microtomographic and histomorphometric study.

The current study evaluated the healing of critical-size defects (CSD) created in rat calvaria treated with platelet concentrates produced by high-speed (Leukocyte- and Platelet-Rich Fibrin - L-PRF) and low-speed (Advanced Platelet-Rich Fibrin - A-PRF) protocols of centrifugation. Twenty-four rats were distributed into three groups: Control, L-PRF, and A-PRF. Five mm diameter CSD were created on the animals' calvaria. The defects of the L-PRF and A-PRF groups were filled with 0.01 ml of L-PRF and A-PRF, respectively. The control group defects were filled with a blood clot only. All animals were euthanized on the 35th postoperative day. Histomorphometric and microtomographic analyses were then performed. The L-PRF and A-PRF groups had significantly higher bone volume and neoformed bone area than those of the control group and lowered bone porosity values (p < .05). No significant differences were observed between A-PRF and L-PRF groups for the analyzed parameters. Therefore, it can be concluded that i) L-PRF and A-PRF potentiated the healing of CSD in rat calvaria; ii) high and low-speed centrifugation protocols did not produce PRF matrices with different biological impacts on the amount of bone neoformation.

Which Histometric Analysis Approach Is More Reliable for Assessing Histological Bone Tissue Samples?

This study aims to evaluate the grid of Merz and ImageJ methods for histometric quantification, verifying which is more reliable and defining which is most suitable based on the time required to perform. Thirty histological samples of maxillary sinuses grafted with xenografts were evaluated using an optical light microscope attached to an image capture camera and connected to a microcomputer. The images were digitalized and recorded as a TIFF image, and the new bone formation was evaluated using the grid of Merz and ImageJ. The Bland-Altman analysis was used to identify the agreement between the methods and determine suitable future research options. The timing of the quantification was also performed to identify a possible advantage. The mean value for the quantification analysis timing for the grid of Merz was 194.9 ± 72.0 s and for ImageJ was 871.7 ± 264.4, with statistical significance between the groups (p = 0.0001). The Bland-Altman analysis demonstrated a concordance between the methods, due to the bias being next to the maximum concordance (-1.25) in addition to the graphic showing the scattering points next to the mean of differences and inside of limits of agreement. Thus, it was demonstrated that the grid of Merz presents reliable outcomes and advantages over the ImageJ methodology regarding the time spent to contour the areas of interest.

The Use of Hydroxyapatite Loaded with Doxycycline (HADOX) in Dentoalveolar Surgery as a Risk-Reduction Therapeutic Protocol in Subjects Treated with Different Bisphosphonate Dosages.

Medication-related osteonecrosis of the jaw (MRONJ) is considered as a severe adverse side effect of specific drugs such as anti-resorptive and anti-angiogenic medications. Evidence suggests that MRONJ is linked to invasive dental procedures, mainly dentoalveolar surgery. Several preventive strategies to minimize the risk of developing MRONJ have been investigated. However, no investigation has been attempted to evaluate the therapeutic effect of local drug-delivery technology as a preventive strategy protocol. The aim of this study is to evaluate the efficacy of hydroxyapatite-containing doxycycline (HADOX) in rats with high-risk MRONJ development. All the rats used in this study were divided into seven groups. Six groups of rats out of seven were exposed to two different doses of antiresorptive drug therapy for four weeks before undergoing an upper incisor extraction. After 28 days, all the animals were euthanized, and the bone blocks were processed for histological and histomorphometrical evaluation. The histomorphometric analysis confirmed that newly formed bone (NFB) was present in all groups, with significant differences. NFB in the HADOX group treated with zoledronic acid at 4% showed (28.38; C.I. 22.29-34.48), which represents a significant increase compared to HA (15.69; C.I. 4.89-26.48) (p = 0.02). A similar pattern was observed in the HADOX group treated with zoledronic acid 8% ZA treatment (p = 0.001). Conclusions: HADOX did not inhibit any bone repair and reduced early inflammatory response. Hence, HADOX could promote bone healing in patients undergoing antiresorptive drug therapy.

Are the imaging-based techniques for early diagnosis of oral potentially malignant lesions effective?

Design The study was a systematic review and meta-analysis conducted in accordance with the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement and the guidelines from the Cochrane handbook for systematic reviews of interventions.Data sources Literature searches of free text and MeSH terms were performed using Medline (PubMed), Scopus, Google Scholar and the Cochrane Library (from 2000 to 30 June 2020). The search strategy was: ("oral screening devices" or "autofluorescence" or "chemiluminescence" or "optical imaging" or "imaging technique") and ("oral dysplasia" or "oral malignant lesions" or "oral precancerosis").Data analysis After identification of 1,282 potential articles, an analysis applying the eligibility criteria to the research identified 43 articles for qualitative evaluation and 34 for quantitative analysis.Results The results presented were inconsistent, both in the whole and in technique groups. There was evidence of high risk of bias in the evaluated studies. Moreover, the results were homogeneous across studies, which makes it challenging to carry out a reliable comparison of measures like specificity or positive/negative predictive values.Conclusions Imaging-based techniques for early diagnosis of potentially malignant oral lesions must improve technology and accuracy. In addition, none of the evaluated methods can substitute the oral biopsy.

Is the implant-retained overdenture a solution to improve the patient quality of life?

Design The research was a retrospective cohort study evaluating a study which performed routine control sessions to assess bone loss around the dental implant over five years and 12 and 24 months, after their prosthetic restorations.Aim The study aimed to evaluate patients' dental implant marginal bone loss after oral rehabilitation with bar and locator retainers and their possible complications.Methods A study of 114 patients who had received 283 dental implants from 2013-2018 was conducted. Two follow-up recall sessions were conducted, one at 12 months and one at 24 months, after dentures were placed. Intraoral and extraoral examinations were also conducted in addition to clinical assessments. The patients' prostheses were assessed for occlusion, tissue health and soft-tissue continuity, complaints, implant success rates and marginal bone loss, in addition to prosthetic complications, at follow-up sessions.Results In this study, 94 patients were fitted with implant-supported removable prostheses on locator attachments on both arches and 20 were fitted with removable prostheses using bar attachments. After evaluating the location of the implant, the number of days after implantation and the type of retainer in all patients, both groups showed a significant amount of marginal bone loss in the 12th and 24th months. The presence of complications was significantly associated with both prosthesis types at month 24 (p >0.05). When the relation between the position of the denture and the presence of complications at month 12 was evaluated, 36% of the complications were observed in the maxilla and 21.3% in the mandible. There was no significant difference associated between denture location and complication presence at month 24 (p >0.05).Conclusions Even though complications do not affect marginal bone loss, a patient's failure to maintain adequate oral hygiene results in marginal bone loss. Therefore, it appears that regular post-treatment prosthesis inspections are essential. If the requirements resulting from these inspections are satisfied, future complications may be prevented.

Is a digital surgical guide superior for implant placement in the first molars areas?

Design The study was a randomised clinical trial comparing two independent groups for implant placement. One group was a computer-aided design/computer-aided manufacturing (CAD/CAM) implant guide (digital) and the other one used the traditional implant guide (traditional impression).Aim The study aimed to compare the outcomes of two different methods of guidance for surgical implants for missing first molars. One was prepared by intraoral digital scanning. The other was the conventional impression, which includes time to make an impression and perform surgery, fit of intraoral guide and deviation in screw access channels position. The purpose of the study was not only to find the most suitable implant guide but also to allow dentists to justify their chosen method.Methods The authors of this study included 42 participants with first molars missing and distributed them into two groups, one group using a digital production guide and the other using a traditional impression. The evaluation measured the deviation length and direction of the screw access channel position relative to implant alignments. In addition, labour time for implant guides and the intraoral fit were assessed as secondary outcomes.Results The impression time and implant surgery time for patients in the digital group were shorter than for those in the traditional group. The intraoral first fit of the guide was better for patients who underwent treatment with a digital system than it was for control patients (p <0.05). The one-time satisfaction rate of the digital group was 100%, while five cases in the control group required repetition. The difference between screw access channel positions on the left and right sides for both groups showed no significant differences.Conclusions The digital surgical guide for a first molar implant reduces the clinical, operative time and screw access deviation and therefore improves efficiency. Improved clinical outcomes indicated that there is evidence to support the use of CAD/CAM guides in dental implant placement for a single missing tooth replacement.

Biological characterization of an injectable platelet-rich fibrin mixture consisting of autologous albumin gel and liquid platelet-rich fibrin (Alb-PRF).

Platelet-rich fibrin (PRF) has been proposed as an autologous membrane with the advantages of host accumulation of platelets and leukocytes with entrapment of growth factors. However, limitations include its faster resorption properties (~2 weeks). Interestingly, recent studies have demonstrated that by heating a liquid platelet-poor plasma (PPP) layer, the resorption properties of heated albumin (albumin gel) can be extended from 2 weeks to greater than 4 months (e-PRF). The aim of the present study was to characterize the biological properties of this novel regenerative modality. Whole blood collected from peripheral blood in 9-mL plastic tubes was centrifuged at 700 g for 8 minutes. Thereafter, the platelet-poor plasma layer was heated at 75°C for 10 minutes to create denatured albumin (albumin gel). The remaining cells and growth factor found within the buffy coat layer (liquid PRF) were thereafter mixed back together with the cooled albumin gel to form Alb-PRF. Histological analysis, including the distribution of cells within Alb-PRF, was then performed. Seven different growth factor release kinetics from Alb-PRF were characterized up to 10 days, including PDGF-AA, PDGF-AB, PDGF-BB, TGF-ß1, VEGF, IGF and EGF. Thereafter, gingival fibroblast cell responses to Alb-PRF were investigated by means of a live/dead assay at 24 hours; migration assay at 24 hours; proliferation assay at 1, 3 and 5 days; real-time PCR for the expression of TGF-ß and collagen 1a2 at 3 and 7 days; and collagen 1 immunostaining at 14 days. It was first observed histologically that viable cells were evenly distributed throughout the Alb-PRF formulation. Growth factor release demonstrated a slow and gradual release, particularly for TGF-ß1 and PDGF-AA/AB, during the entire 10-day period. Alb-PRF also exhibited statistically significantly higher cell biocompatibility at 24 hours and statistically significantly induced greater fibroblast proliferation at 5 days when compared to those of control TCP. Alb-PRF further induced statistically significantly greater mRNA levels of TGF-ß at 3 and 7 days, as well as collagen 1 at 7 days. The present results indicate that Alb-PRF possesses regenerative properties induced by the slow and gradual release of growth factors found in liquid PRF via albumin gel degradation. Future studies are thus warranted to fully characterize the degradation properties of Alb-PRF in vivo and explore future clinical applications in various fields of medicine.

In vivo evaluation of the biocompatibility and biodegradation of a new denatured plasma membrane combined with liquid PRF (Alb-PRF).

Guided bone regeneration (GBR) is a process that involves the regeneration of bone defects through the application of occlusive membranes that mechanically exclude the population of non-osteogenic cells from the surrounding soft tissue. Interestingly, platelet-rich fibrin (PRF) has previously been proposed as an autologous GBR membrane despite its short-term resorption period of 2-3 weeks. Recent clinical observations have demonstrated that, by heating a liquid platelet-poor plasma (PPP) layer and mixing the cell-rich buffy coat zone, the resorption properties of heated albumin gel with liquid-PRF (Alb-PRF) can be significantly improved. The aim of this study was to evaluate the inflammatory reaction, biocompatibility, and extended degradation properties of a new autologous Alb-PRF membrane in comparison to commonly utilized standard PRF after nude mice implantation, according to ISO 10993-6/2016. Two standard preparations of PRF (L-PRF and H-PRF) were compared to novel Alb-PRF following subcutaneous implantation at 7, 14, and 21 days. All groups demonstrated excellent biocompatibility owing to their autologous sources. However, it is worth noting that, while both L-PRF and H-PRF membranes demonstrated significant or complete resorption by 21 days, the Alb-PRF membrane remained volume-stable throughout the duration of the study. This study demonstrates-for the first time, to the best of our knowledge-a marked improvement in the membrane stability of Alb-PRF. This indicates its future potential for use as a biological barrier membrane for GBR procedures with a long-lasting half-life, or as a biological filler material in esthetic medicine applications. Thus, further studies are warranted to explore future clinical applications in various fields of medicine.