Comparative Analysis of Internal Tapered Implant-Abutment Connections: Evaluating the Morse Effect.

The purpose of the present study was to evaluate the Morse effect of different internal tapered implant-abutment connections (ITCs) using a pullout test. Implants with different ITCs were selected: Short (Bicon, USA), G1; Novo Colosso (Medens, Brazil), G2; Epkut (SIN, Brazil), G3; Strong SW (SIN, Brazil), G4; Flash (Conexão, Brazil), G5 and Bone Level (Straumann, Switzerland), G6. The respective CAD files were loaded into the analysis software to measure each ITC's taper angle and implant-abutment contact area. Six implants from each group were embedded in acrylic resin blocks, and the respective universal abutments were fixed using a mallet (G1) or by applying 20 Ncm of torque (G2 to G6). After ten minutes, each abutment's retention screw was removed, and the force necessary for abutment rupture was recorded using a universal testing machine at a crosshead speed of 0.5 mm/min. The groups were compared using a one-way ANOVA and Tukey's test. Spearman's correlation was used to check the correlation of the taper angle and contacting area with the pullout strength. G1, a no-screw abutment with a 3° taper, and G2, a 10°tapered abutment tightened by 20 Ncm, presented the highest pullout strength (p<.05). The increased taper angle of G4, compared to G3, reduced the Morse effect despite their similar implant-abutment contacting areas (p<0.05). The G5 and G6 abutments loosened after screw removal and did not exhibit pullout resistance. The closer the tapered angle (r=-.958) and the higher the implant-abutment contact area (r=.880), the higher the pullout strength (p<.001). Within the limits of this study, the Morse effect is different among tapered implant-abutment connections. The closer the tapered angle and the higher the interface area, the higher the Morse effect between the abutment and the implant.

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.

Solid PRF Serves as Basis for Guided Open Wound Healing of the Ridge after Tooth Extraction by Accelerating the Wound Healing Time Course-A Prospective Parallel Arm Randomized Controlled Single Blind Trial.

Systematic evaluations regarding the influence of PRF in ridge sealing are still lacking. To the best of our knowledge, this is the first systemic randomized, controlled, clinical approach dealing with the potential of a systematic applied solid PRF on soft tissue socket healing of molar and premolar extraction sockets with evaluation for up to 90 days. Qualitative and quantitative image analysis showed that PRF contributed to a significantly faster ridge sealing, within the period of 7-10 days in both tooth types. This led to a visibly less contraction at the PRF-treated group sites at day 90. Patients' pain perception demonstrated no statistic significance between both groups (PRF vs. natural healing), but the patients in PRF group seemed to have had less pain throughout the observational period. It becomes evident that PRF is able to serve as a promotor of the secondary wound healing cascade. The guiding capacity of PRF accelerating the process of open ridge healing makes it possible to act as a natural growth factor drug delivery system, providing a more predictable guided open wound healing of the ridge with less contraction of the soft tissue, the latter being a key factor for the subsequent successful dental implantation and oral rehabilitation.

A Standardized g-Force Allows the Preparation of Similar Platelet-Rich Fibrin Qualities Regardless of Rotor Angle.

Platelet-rich fibrin (PRF) is an autologous blood concentrate that supports tissue regeneration. The effect of the centrifuge rotor angle in the fabrication of PRF is still not fully elucidated. The hypothesis of this study is: When applying the same g-force (relative centrifugal force [RCF]) and centrifugation time, PRF components and bioactivity are not modified using either a swing-out rotor or a fixed angle rotor. For this purpose, peripheral blood samples (from five donors) were used to gain solid (710 ×g, 8 min) and liquid (44 ×g, 8 min) PRF matrices using three different centrifuges (one fixed angle as a control and two different swing-out rotor centrifuges). The physical characteristics of the solid PRF were measured to evaluate the clot formation and cellular distribution. The liquid PRF was used to evaluate the cell number, bioactivity, and influence on primary human osteoblasts (pOBs) and primary human fibroblasts (pHFs) in vitro. Solid PRF clots were significantly larger in the group of fixed rotor centrifuges compared with either of the two evaluated swing-out rotor centrifuges. No differences were observed when evaluating the cellular distribution within the solid PRF. No statistically significant differences were documented in the cell's density in liquid PRF samples (platelets, lymphocytes, neutrophils, eosinophils, and basophils) among the differently gained PRF samples. No statistically significant differences were documented for the released growth factors (vascular endothelial growth factor, epidermal growth factor, and transforming growth factor beta 1) over 7 days. pOBs and pHFs viability after treatment with PRF conditioned media showed no statistically significant differences between the evaluated groups. However, the number of adherent cells treated with PRF obtained with the use of the fixed angle rotor was significantly higher when compared with those treated with PRF obtained by using the swing-out rotors. The presented results confirm that regardless of the centrifuge rotor used, the components and bioactivity of solid and liquid PRF matrices are modified by the applied RCF and centrifugation time. These findings are of great importance for highlighting the essential role of adapting the centrifugation protocols when using different centrifuges and to correctly report the used centrifugation protocols in scientific research to allow for reproducible results. Impact statement Platelet-rich fibrin (PRF) is prepared from autologous peripheral blood and is widely applied in research and clinical treatments. The centrifugation parameters used during the preparation of PRF directly influence its components and bioactivity. By using a standardized protocol, the present study demonstrated that adapting various centrifuges to a standardized relative centrifugal force and centrifugation protocol resulted in reproducible PRF matrices with similar bioactivity, regardless of the centrifuge rotor angle. These findings underline the necessity to carefully adapt and correctly report the used centrifuge and centrifugation protocols in scientific research to allow reproducible results.