Bruxism (teeth grinding and clenching) is generally considered a contraindication for dental implants, although the evidence for this is usually based on clinical experience only. So far, studies to the possible cause-and-effect relationship between bruxism and implant failure do not yield consistent and specific outcomes. This is partly because of the large variation in the literature in terms of both the technical aspects and the biological aspects of the study material. Although there is still no proof for the suggestion that bruxism causes an overload of dental implants and of their suprastructures, a careful approach is recommended. There are a few practical guidelines as to minimize the chance of implant failure. Besides the recommendation to reduce or eliminate bruxism itself, these guidelines concern the number and dimensions of the implants, the design of the occlusion and articulation patterns, and the protection of the final result with a hard occlusal stabilization splint (night guard).

The aim of this study was to determine the intra- and interobserver reliability and validity of the instrumental assessment of primary dental implant stability, using resonance frequency analysis (RFA). Sixteen tapered implants and 16 cylindrical implants were installed in eight unfixed dry human mandibles (Cawood classification IV/V). Implant stability quotients (ISQ; the outcome variable of RFA) and peak removal torque were determined. Both the intra-observer reliability and the interobserver reliability of the RFA measurements were fair-to-good, while no significant correlations between the ISQ values and removal torque were found. The removal torque of the cylindrical implants was higher than that of the tapered implants. The smallest detectable difference was almost nine ISQ units. Within the limitations of the present dry cadaver study, it was concluded that (i) primary dental implant stability can be assessed reliably with RFA measurements, (ii) the concurrent validity between RFA measurements and removal torque is poor, (iii) cylindrical implants may be more stable than tapered ones and (iv) two subsequent readings of RFA measurements need to differ at least nine ISQ units before the difference between the two measurements can be considered statistically significant. More research is needed to see whether these conclusions can be extrapolated to the clinical situation, including the assessment of implants during function (secondary stability).

Aims The aim of the present study was to assess the association between dental implant stability and peripheral blood cell composition and levels of coagulation factors in patients treated with alveolar ridge preservation with platelet‐rich fibrin (PRF) and bovine bone substitute. Materials and methods Fifty patients were included between 2015 and 2017. PRF was prepared from autologous blood, in which blood cells and coagulation factor levels were measured. PRF and bovine bone were placed in the socket, followed by closure with PRF membrane. Implants were placed 14 (±2.5) weeks postextraction. The implant stability quotient was measured at t = 0, t = 10 days, t = 7 weeks, and t = 17 weeks by resonance frequency analysis. Results Erythrocyte count was inversely associated with PRF membrane length, but not with implant stability. Conversely, platelet count did not correlate with membrane size but inversely correlated with implant stability at 7 and 17 weeks. In addition, implant stability was directly correlated with levels FXIII (t = 0, p < .01), active von Willebrand factor (VWF; t = 0 and 7 weeks, p < .05), and total VWF (t = 7 weeks, p = .012). Conclusion Implant stability following alveolar ridge preservation with PRF and bovine bone substitute is associated with circulating blood cells and coagulation factors. In particular, fibrin structure, VWF, and FXIII may be important modulators of implant stability.

Replacement in the esthetic zone can be very unpredictable and difficult to manage in cases with extreme bone and soft tissue loss. In this case report (2.5‐year follow‐up), we demonstrate that the use of platelet‐rich fibrin in combination with bovine bone can result in a stable, esthetic outcome.

BackgroundUpon tooth extraction, extravascular tissue factor (TF) initiates coagulation to arrest bleeding. Additionally, saliva is in constant contact with the wound and contains extracellular vesicle‐derived procoagulant TF. Since the duration of postextraction bleeding is highly variable between patients, we hypothesized this may be caused by variation in saliva‐derived TF‐induced clotting activity.ObjectivesWe aimed to assess the variability of saliva‐induced thrombin generation (TG) in healthy individuals.Methods TG was performed according to the calibrated automated thrombinography (CAT) method. Diluted saliva was added (instead of recombinant TF and phospholipids [PL]) to normal pooled plasma (NPP) in the absence/presence of anti‐TF antibodies. Saliva was collected from healthy individuals in the morning, afternoon and evening.ResultsAddition of saliva to NPP induced TG curves similar to those induced by r‐TF and PL. Moreover, addition of anti‐TF antibodies abolished saliva‐induced TG, indicating TF‐dependence. A large inter‐individual variability (peak CV 31%, range 73‐220 nmol/L thrombin) in saliva‐induced TG was observed. Interestingly, within subjects, saliva‐induced TG was significantly (P = 0.009) increased in the morning (167 ± 40 nmol/L thrombin) compared to the afternoon (124 ± 39 nmol/L thrombin) and evening (123 ± 38 nmol/L thrombin). This diurnal variation was not attributable to gingival stimulation or damage induced by tooth brushing.ConclusionsWe identified a diurnal rhythm in salivary TF activity that may have implications for tooth extraction and dental surgery, as performing invasive procedures in the morning may be beneficial for rapid coagulation. Future studies should correlate salivary TF to clinical outcome (ie, postextraction bleeding) and assess a possible relation with bacterial status in the oral cavity.