Bone healing with or without platelet-rich plasma around four different dental implant surfaces in beagle dogs.

PURPOSE: Surface development is one of the major aims in dental implant engineering. Additive application of substances could possibly improve the new bone formation around dental implants. The present study evaluated the bone reaction on four different implant surfaces with or without platelet-rich plasma (PRP). MATERIALS AND METHODS: Four self-tapping titanium screw implants (Brånemark MK III [Nobel Biocare, Göteborg, Sweden], Osseotite [3i, Miami, FL, USA], Xive [Densply Friadent, Mannheim, Germany], and Compress [IGfZ eG, Diez, Germany]) with different surfaces were inserted in each hemimandible of 12 female beagle dogs; the implant positions and the application of PRP were randomized. After intravital fluorochrome staining, sacrifices and biopsies harvesting were performed after 6 weeks (five dogs; one dog died before) and 12 weeks (six dogs) and the respective specimens were analyzed. RESULTS: The only significant difference in bone remodeling was found for the Compress implants with increased bone formation compared with the Brånemark implants at 12 weeks (sign test, p = .03). Comparing the histological and histomorphometric specimens of all other implant surfaces with respect to peri-implant bone remodeling and the resulting bone-implant contact rates (BICRs), no statistically significant differences were seen in the PRP or non-PRP groups (sign test, all p values ≥ .063). CONCLUSIONS: This study found no significant differences in the BICR for roughened implant surfaces compared with machined surfaces. In this animal model, the addition of PRP did not demonstrate evidence of faster bone formation or the resulting BICR.

Comparison of point-of-care methods for preparation of platelet concentrate (platelet-rich plasma).

PURPOSE: This study analyzed the concentrations of platelets and growth factors in platelet-rich plasma (PRP), which are likely to depend on the method used for its production. MATERIALS AND METHODS: The cellular composition and growth factor content of platelet concentrates (platelet-rich plasma) produced by six different procedures were quantitatively analyzed and compared. Platelet and leukocyte counts were determined on an automatic cell counter, and analysis of growth factors was performed using enzyme-linked immunosorbent assay. RESULTS: The principal differences between the analyzed PRP production methods (blood bank method of intermittent flow centrifuge system/platelet apheresis and by the five point-of-care methods) and the resulting platelet concentrates were evaluated with regard to resulting platelet, leukocyte, and growth factor levels. The platelet counts in both whole blood and PRP were generally higher in women than in men; no differences were observed with regard to age. Statistical analysis of platelet-derived growth factor AB (PDGF-AB) and transforming growth factor ß1 (TGF-ß1) showed no differences with regard to age or gender. Platelet counts and TGF-ß1 concentration correlated closely, as did platelet counts and PDGF-AB levels. There were only rare correlations between leukocyte counts and PDGF-AB levels, but comparison of leukocyte counts and PDGF-AB levels demonstrated certain parallel tendencies. CONCLUSIONS: TGF-ß1 levels derive in substantial part from platelets and emphasize the role of leukocytes, in addition to that of platelets, as a source of growth factors in PRP. All methods of producing PRP showed high variability in platelet counts and growth factor levels. The highest growth factor levels were found in the PRP prepared using the Platelet Concentrate Collection System manufactured by Biomet 3i.

A comparison of three different attachment systems for mandibular two-implant overdentures: one-year report.

BACKGROUND: There is a lack of clinical studies on the self-aligning attachment system (Locator(R); Zest Anchors, Inc. homepage, Escondido, CA, USA) for two-implant-retained overdentures in the edentulous mandible. Therefore, a comparison of the Locator with two traditional designs (a rotational gold matrix and a rubber O-ring type) in clinical 1-year use was conducted. MATERIALS AND METHODS: From 2003 to 2007, 60 patients received two Osseotite(R) TG Standard implants (BIOMET 3i Implant Innovations, Palm Beach Gardens, FL, USA) in the intraforaminal area of the edentulous mandible. The implants were left unloaded for 3.5 months, randomized to three different attachment systems, and loaded through a mandibular overdenture. Twenty-three patients received a self-aligning attachment system (Locator) and 33 patients a ball attachment (Dal-Ro(R)[BIOMET 3i Implant Innovations]n = 25; TG-O-Ring(R)[Cendres & Metaux SA, Biel-Bienne, Switzerland]n = 8). After 12 months of delivery of the overdentures, the oral situation was evaluated: prosthodontic maintenance and biologic complications, subjective patients' experience, and oral health-related life quality (Oral Health Impact Profile [OHIP-G 49]). RESULTS: After 1-year of clinical service, 8 of 120 implants were lost (9.6%). The Locator system brought up 34 prosthetic complications, especially the need for change of the male parts or activation because of loss of retention. The TG-O-Ring patients showed 14 complications, most of them the change of the O-Rings. The patients with the Dal-Ro abutment had seven minor complications in 12 months of clinical use. Biologic complications and patients' oral health-related life quality showed no significant difference among the three experimental groups. CONCLUSIONS: Prosthodontic maintenance was restricted to loss of retention for all systems. Within the observation period of this study, the self-aligning attachment system showed a higher rate of maintenance than the ball attachments. The patients' oral health-related life qualities as well as the biologic parameters do not differ when using the three abutment systems.

Severe third molar complications including death-lessons from 100 cases requiring hospitalization.

PURPOSE: In this study we investigated patients that were hospitalized due to third molar (M3) complications. Specifically we analyzed frequency, age distribution, and outcome with respect to the M3 clinical status. PATIENTS AND METHODS: We set up a prospective cohort study and included 100 subjects admitted for management of acute M3-associated complications. The clinical status of the M3 was defined as 1) prophylactic M3 removal, 2) therapeutic (nonelective) M3 removal, or 3) M3 present at the time of admission. Outcome variables were clinical infection markers (C-reactive protein, leukocyte counts) and economic parameters (treatment costs, length of hospital stay, and days of disability). Nonparametric tests were used for comparison of subpopulations (surgical vs nonsurgical, prophylaxis-related vs nonprophylaxis-related). RESULTS: One third of the 100 patients were age 40 or older. Overall 80 severe infections, 11 mandibular fractures, 3 nerve injuries, 5 tooth/root luxations, and 1 postoperative hemorrhage were noticed. Twenty-seven complications resulted from prophylactic surgery, 44 from nonelective removal, and 29 from pericoronitis. Postoperatively, a 77-year-old male patient hospitalized with nonelective removal sustained fatal myocardial infarction. Treatment costs were 260,086 euro (mean 2,608 euro/case); total days of disability were 1,534. The postsurgical complications showed higher C-reactive protein values compared with pericoronitis-induced complications. CONCLUSIONS: Within the catchment area of our institution, the majority of complications requiring hospitalization resulted from diseased third molars or their removal. Side effects of observational strategies such as the shifting of complications to higher ages deserve future attention.

Third molar complications requiring hospitalization.

OBJECTIVE: The aim of this study was to describe demographic and clinical patterns of subjects hospitalized with complications associated with third molars (M3). STUDY DESIGN: The investigation was designed as a prospective cohort study composed of subjects admitted to hospital for management of M3-associated complications. The predictor variable was "clinical status of the M3" defined as (A) prophylactic M3 removal, (B) nonelective M3 removal, or (C) M3 present at the time of admission. Outcome variables were infection parameters, treatment costs, length of hospital stay, and days of disability. Postoperative complications (A and B) were compared to complications based on pericoronitis (C). Complications due to prophylactic removal (A) were compared to those arising from pericoronitis or from the removal of symptomatic teeth (B and C). RESULTS: From January 2003 to December 2004, 45 deep space infections, 6 mandibular fractures, 2 lingual nerve injuries, 1 parapharyngeal tooth luxation, and 1 osteomyelitis were noticed. Fifteen complications resulted from prophylactic surgery (A), 25 from nonelective removal (B), and 15 from pericoronitis (C). Direct treatment costs were 147,000 euro (A: 42,000 euro; B: 74,000 euro; C: 31,000 euro). In 10 of the 15 patients of group C, deep space involvement resulted immediately from the first episode of pericoronitis. Neither clinical markers of infection nor economic parameters showed significant differences between the groups. CONCLUSION: Within the catchment area of our institution, the majority of third molar-related hospitalizations resulted from diseased third molars or their removal.

Comparison of the platelet concentrate collection system with the plasma-rich-in-growth-factors kit to produce platelet-rich plasma: a technical report.

PURPOSE: The aim of this study was to compare a new method for the production of platelet-rich plasma (PRP), the plasma-rich-in-growth-factors kit (PRGF kit; G.A.C. Medicale San Antonio, Vitoria, Spain), with an established method, the Platelet Concentrate Collection System (PCCS; 3i/Implant Innovations, Palm Beach Gardens, FL) with respect to resulting cellular and growth factor contents. MATERIALS AND METHODS: Whole blood was drawn from 51 healthy donors (20 men, 31 women) aged 19 to 59 years (mean +/- SD 35.12 +/- 9.65 years), and PRP was prepared by both methods. RESULTS: Platelet counts differed significantly (signed rank test, P < .001 for all) between the donor blood (274,200 +/- 54,050/microL), the PCCS PRP preparation (1,641,800 +/- 426,820/microL), and the PRGF kit PRP preparation (513,630 +/- 139,470/microL). The PCCS concentrated leukocytes (whole blood, 6,992 +/- 2,011/microL; PCCS PRP, 14,153 +/- 7,577/microL), while the PRGF kit produced a leukocyte-poor PRP (65 +/- 108/microL). Higher concentrations of transforming growth factor beta1 (TGF-beta1) and platelet-derived growth factor AB (PDGF-AB) were found in the PCCS PRP (TGF-/beta1, 290 +/- 95 ng/mL; PDGF-AB, 157 +/- 62 ng/mL) than in the Anitua PRGF kit PRP (TGF-beta1, 73 +/- 26 ng/mL; PDGF-AB, 47 +/- 21 ng/mL). Statistical analysis showed significant differences (P < .001 for TGF-beta1 and P < .01 for PDGF-AB). DISCUSSION: The results of this study and some data in the literature indicate that the content of growth factors in PRP can vary tremendously, depending on the system used for the preparation of PRP. CONCLUSION: PCCS collects more platelets and leukocytes than the PRGF kit. This results in significantly higher growth factor levels. Further in vivo studies are needed to determine whether this results in a clinically different biologic effect.

Comparison of platelet, leukocyte, and growth factor levels in point-of-care platelet-enriched plasma, prepared using a modified Curasan kit, with preparations received from a local blood bank.

The potential use of autologous thrombocytic growth factors to accelerate bone regeneration requires improved methods of isolating platelet-rich plasma (PRP). In addition to discontinuous cell separation, a second method by which PRP is produced at the point-of-care has now become available. In this study, growth factor levels in PRP from these two sources were compared. Whole blood was drawn from 115 healthy donors (73 males, 42 females) aged 21 - 62 years (mean 36, SD 10). The PRP was separated by the blood bank (BB) using the discontinuous cell separation method or at the 'point-of-care' by the so-called 'buffy coat' method (analogous to the Curasan PRP Kit). Growth factor content differed significantly for TGF-beta1 (BB 268.65+/-70.77 ng/ml, Curasan 95.02+/-60.67 ng/ml (sign test P<0.001)) and PDGF-AB (BB 133.59+/-46.26 ng/ml, Curasan 233.70+/-111.86 ng/ml (P<0.001)), while the content of IGF-I (BB 85.37+/-25.58 ng/ml, Curasan 101.72+/-47.7 ng/ml (P<0.160)) showed no significant difference. The higher thrombocyte count in the BB PRP (BB 1434300+/-351960/ microl, Curasan 908.500+/-492.30/microl) seems to result in higher TGF-beta1 levels, while the higher leukocyte count in the Curasan PRP (BB 160+/-320/ microl, Curasan 30130+/-12500/microl) seems to result in higher PDGF-AB levels. The similar IGF-I levels in the two preparations might merely reflect similar amounts of plasma in the PRP produced by each approach.

The Harvest Smart PRePTM system versus the Friadent-Schütze platelet-rich plasma kit.

An important reason to improve methods for isolating platelet-rich plasma (PRP) is the potential use of autogenous platelet growth factors. In addition to the Curasan PRP kit (Curasan, Kleinostheim, Germany) and the platelet concentrated collection system (PCCSTM) system, two new methods for the preparation of PRP by the surgeon are now available. This study compared the suitability of these new methods for the preparation of PRP. Whole blood was drawn from 54 healthy donors (33 men and 21 women) aged 23-79 years (38.0 +/- 17.7 years). PRP was prepared from each donor's blood using both the Smart PRePTM system (Harvest Technologies Corporation, Munich, Germany) and the Friadent-Schütze method (PRP kit; Friadent-Schütze, Vienna, Austria). The platelet count in donor whole blood was 276 810 +/- 59 440 /microl. Platelet counts differed significantly between the Smart PRP preparation (1227 890 +/- 312 440 platelets/microl) and the Friadent-Schütze PRP preparation (1440 500 +/- 501 700 platelets/microl) (sign test, P < 0.001). The Smart PRePTM system had a significantly higher collection efficiency (63.4 +/- 7.9%) than the Friadent-Schütze kit (49.6 +/- 13.6%) (sign test, P < 0.001). The leukocyte contents in the two platelet concentrates were similar (Smart PRePTM, 19 261 +/- 8082 platelets/microl; Friadent-Schütze, 21 691 +/- 16 430). Transforming growth factor (TGF)-beta1 and platelet-derived growth factor (PDGF)-AB were higher in the Friadent-Schütze PRP (TGF-beta1, 196.8 +/- 109.6 ng/ml; PDGF-AB, 251.6 +/- 115.4 ng/ml) than in the Smart PRePTM (TGF-beta1, 77.2 +/- 54.8 ng/ml; PDGF-AB, 208 +/- 85.2 ng/ml). The sign test indicated significant differences between the two methods in the concentrations of TGF-beta1 (P < 0.001) and PDGF-AB (P < 0.01). Insulin-like growth factor (IGF)-1 levels in the two PRP preparations were similar (Friadent-Schütze PRP, 72.8 +/- 22.3 ng/ml; Smart PRePTM, 91.4 +/- 21.3 ng/ml). The Smart PRePTM system was superior with respect to ease of handling and preparation time. It also had a significantly higher platelet collection efficiency than the Friadent-Schütze PRePTM kit. The Friadent-Schütze PRP kit offers a slight advantage in the resulting PRP platelet concentration. However, this is easily compensated for in the Smart PRePTM system by reducing the volume of the resulting PRP.

Quantification of thrombocyte growth factors in platelet concentrates produced by discontinuous cell separation.

Platelet concentrates (PC) are increasingly used to increase bone regeneration in pre-prosthetic surgery. Although it is generally appreciated that certain growth factors (PDGF, TGF, EGF, and ECGF) are present in thrombocyte preparations, relatively little is known about these components in quantitative terms. The study reported here analysed the amounts of growth factors in PC produced under standard conditions from healthy volunteers. All the blood samples (237 in total) were analysed using Quantikine ELISA kits (R and D). The mean +/- SD platelet count in whole blood from these donors was 262,000+/-58,000/microl, while in PC produced by discontinuous cell separation it was 1.419,000+/-333,000/microl. The mean growth factor concentrations in PC preparations in ng/ml were as follows: PDGF-AB 125+/-55 ng/ml; TGF-beta1 221+/-92 ng/ml; IGF-I 85+/-25 ng/ml; PDGF-BB 14+/-9 ng/ml; TGF-beta2 0.4+/-0.3 ng/ml. These growth factor concentrations typically covered a 3-10 fold range: PDGF-AB 29-277ng/ml; PDGF-BB 2-33ng/ml; TGF-beta1 32-397ng/ml; TGF-beta2 0.1-1.2 ng/ml; IGF-I 40-138 ng/ml. Platelet counts in PC were slightly higher for women (Mann-Whitney Test all p < 0.001) than for men, while the concentrations of growth factors in PC exhibited no gender-related difference of any statistical significance.

Curasan PRP kit vs. PCCS PRP system. Collection efficiency and platelet counts of two different methods for the preparation of platelet-rich plasma.

An important reason to improve methods of isolating platelet-rich plasma (PRP) is the potential use of autologous thrombocyte growth factors. In addition to discontinuous cell separation, two methods for extracting PRP that can be performed directly by the surgeon are now available. This study compared the suitability of these two methods for the preparation of PRP. Whole blood was drawn from 47 healthy donors (18 men, 29 women) aged 20-59 years (mean 29.9, SD 7.7). For each donor, PRP was separated by the PCCS method (PCCS Kit, 3i Implant Innovations, Palm Beach Gardens, FL, USA) and by the Curasan method (analogous to the PRP kit, Curasan, Kleinostheim, Germany). Thrombocyte counts differed significantly (sign test P = 0.001) between the donor blood (mean 290,000/ micro l, SD 86,000/ microl), the PCCS PRP preparation (mean 2,209,000/ microl, SD 901,000/ microl), and the Curasan PRP (mean 1,075,000/ micro l, SD 636,000/ microl). The correlation between the thrombocyte count in the PRP and the thrombocyte count in the donor whole blood was greater for the PCCS PRP (Spearman's correlation coefficient rS = 0.60) than for the Curasan PRP (r(S) = 0.34). A slight, clinically irrelevant, influence of gender on thrombocyte concentration in whole blood was found, but no influence of age was detected.

Growth factor levels in platelet-rich plasma and correlations with donor age, sex, and platelet count.

INTRODUCTION: Platelet-rich plasma contains autologous thrombocyte growth factors and might be promising for acceleration of dentoalveolar bone regeneration. In this study, it was analysed for platelet counts and growth factor concentrations. MATERIAL AND METHOD: Platelet-rich plasma was isolated by discontinuous cell separation from 158 healthy men and 55 women aged 17-62 years. One hundred and fifteen specimens (stratified for age and gender of the donor) were analysed for growth factor concentrations and platelet count. RESULTS: The platelet count in platelet-rich plasma (1,407,640+/-320,100/microl) was 5 times higher than in donor blood (266,040+/-60,530/microl). Platelet-derived growth factor AB (117+/-63 ng/ml), transforming growth factor (TGF) beta -1 (169+/-84 ng/ml), and insulin-like growth factor (IGF) I (84+/-23 ng/ml) were found in large amounts, while platelet-derived growth factor (PDGF) BB (10+/-8 ng/ml) and transforming growth factor beta -2 (0.4+/-0.3 ng/ml) were found in small amounts only. The growth factor content was not well correlated with the platelet count in whole blood nor with the platelet-rich plasma (r(p)=0.35). No influence of gender or age on platelet count or growth factor concentrations was discovered (except IGF-I). CONCLUSIONS: While there was substantial variation in the growth factor content of platelet-rich plasma, the factors influencing this are still worthy of further investigation. Furthermore, a technique whereby the growth factor content could be rapidly assessed in platelet-rich plasma may be of therapeutic benefit.

Growth factor levels in the platelet-rich plasma produced by 2 different methods: curasan-type PRP kit versus PCCS PRP system.

PURPOSE: Potential treatments using autologous thrombocyte growth factors are an important reason to improve methods for isolating platelet-rich plasma (PRP). Two methods for extracting PRP directly by the surgeon are currently available; this study was conducted to compare the growth factor levels in the resulting PRP. MATERIALS AND METHODS: Whole blood was drawn from 46 healthy donors (17 men, 29 women) aged 20 to 59 years (29.9 +/- 7.8). PRP was then separated from each sample by both the PCCS (3i) and Curasan (PRP Kit, Curasan) methods. RESULTS: The growth factor content differed significantly for TGF-beta1 (PCCS 467.1 ng/mL; Curasan 79.7 ng/mL) (sign test P < .0001) and PDGF-AB (PCCS 251.8 ng/mL; Curasan 314.1 ng/mL) (P < .0001); this was less significant for IGF-I (PCCS 91.0 ng//mL; Curasan 69.5 ng/mL) (P < .02). The higher platelet count in the PCCS PRP (PCCS 2,232,500/microL; Curasan 1,140,500/microL) seemed to correlate with a higher level of TGF-beta1 (Spearman's correlation coefficient, r(s) = 0.7), whereas the higher leukocyte count in the Curasan PRP (PCCS 15,300/microL; Curasan 33,150/pL) had only a minor correlation with higher levels of PDGF-AB (r(s) = 0.46). DISCUSSION: The PCCS end product has both a higher platelet count and a higher total content of the growth factors investigated. Nevertheless, the biologic effect of the evaluated growth factor levels remains unknown. The amount of PRP necessary to achieve the intended biologic effects still remains unclear. CONCLUSION: PRP contains growth factors in high concentrations. Precise predictions of growth factor levels based on the thrombocyte counts of whole blood or PRP appeared limited. There are different sources for growth factors (platelets, leukocytes, plasma).