Frank Butz

Publications of Frank Butz

• Sinus augmentation with bovine hydroxyapatite/synthetic peptide in a sodium hyaluronate carrier (PepGen P-15 Putty): a clinical investigation of different healing times.

  Authors: Frank Butz, Maria Bächle, Markus Ofer, Katja Marquardt, Ralf J Kohal

  The International journal of oral & maxillofacial implants. 11/2011; 26(6):1317-23.

  Augmentation of the sinus floor with autogenous bone often requires an extra donor site, which is associated with a risk of morbidity, and current grafting protocols involve healing times of up to 9Augmentation of the sinus floor with autogenous bone often requires an extra donor site, which is associated with a risk of morbidity, and current grafting protocols involve healing times of up to 9 months. In this prospective in vivo study, the time-dependent efficacy of PepGen P-15 Putty, a combination of bovine hydroxyapatite and synthetic peptide in a sodium hyaluronate carrier, was evaluated in sinus grafting. Twenty-four edentulous patients received bilateral sinus augmentations with PepGen P-15 Putty, which mimics the cell-binding domain of type I collagen responsible for cell migration, differentiation, and proliferation. The patients were randomly divided into four groups of six patients each, corresponding to 2, 4, 6, and 9 months of healing postaugmentation. After these time intervals, bone biopsy specimens were retrieved through the alveolar bone crest into the augmented sinus, and subsequently oral implants were placed. The specimens were immersed in buffered formalin, scanned with a desktop microcomputed tomography machine, and processed for histologic and histomorphometric evaluation. A mixed model was used for statistical analysis. Three-dimensional microcomputed tomography depicted the distinct structure of trabecular bone encompassing remnants of PepGen, and histologic evaluation revealed osteoblasts and osteoid with osteocytes in the vicinity of the PepGen particles at all healing stages. Histomorphometric results indicated an increase in the newly formed bone fraction in the specimens as follows: 21.3% (± 2.33) at 2 months, 21.9% (± 8.9) at 4 months, 28.5% (± 6.9) at 6 months, and 29.8% (± 11.8) at 9 months. The differences were statistically insignificant. All implants placed in the augmented sites integrated and were restored prosthetically. PepGen can be used successfully for maxillary sinus augmentation. These data provide evidence that implant placement, even after only 2 months of healing, may be possible.

• In vitro reaction of human osteoblasts on alumina-toughened zirconia.

  Authors: Ralf J Kohal, Maria Baechle, Jung S Han, Dennis Hueren, Ute Huebner, Frank Butz

  Clinical oral implants research. 09/2009;

  Abstract Objectives: Alumina toughening enhances the mechanical properties of zirconia ceramics but the biocompatibility of this material has rarely been addressed. In this study, we examined theAbstract Objectives: Alumina toughening enhances the mechanical properties of zirconia ceramics but the biocompatibility of this material has rarely been addressed. In this study, we examined the osteoblast response to alumina-toughened zirconia (ATZ) with different surface topographies. Material and methods: Human osteoblasts isolated from maxillary biopsies of four patients were cultured and seeded onto disks of the following substrates: ATZ with a machined surface, airborne-particle abraded ATZ, airborne-particle abraded and acid etched ATZ. Airborne-particle abraded and acid etched titanium (SLA) and polystyrene disks served as a reference control. The surface topography of the various substrates was characterized by profilometry (R(a), R(p-v)) and scanning electron microscopy (SEM). Cell proliferation, cell-covered surface area, alkaline phophatase (ALP) and osteocalcin production were determined. The cell morphology was analyzed on SEM images. Results: The surface roughness of ATZ was increased by airborne-particle abrasion, but with the R(a) and R(p-v) values showing significantly lower values compared with SLA titanium (Mann-Whitney U-test P<0.05). The proliferation assay revealed no statistically significant differences between the ATZ substrates, SLA titanium and polystyrene (Kruskal-Wallis test, P>0.05). All substrates were densely covered by osteoblasts. ALP and osteocalcin production was similar on the examined surfaces. Cell morphology analysis revealed flat-spread osteoblasts with cellular extensions on all substrates. Conclusions: These results indicate that ATZ may be a viable substrate for the growth and differentiation of human osteoblasts. Surface modification of ATZ by airborne-particle abrasion alone or in combination with acid etching seems not to interfere with the growth and differentiation of the osteoblasts. To cite this article: Kohal RJ, Baechle M, Han JS, Hueren D, Huebner U, Butz F. In vitro reaction of human osteoblasts on alumina-toughened zirconia. Clin. Oral Impl. Res. xx, 2009; 000-000.

• Biomechanical and histological behavior of zirconia implants: an experiment in the rat.

  Authors: Ralf J Kohal, Martin Wolkewitz, Marc Hinze, Jung-Suk Han, Maria Bächle, Frank Butz

  Clinical oral implants research. 05/2009; 20(4):333-9.

  OBJECTIVE: This study aimed at evaluating the integration of zirconia implants in a rat femur model. MATERIAL AND METHODS: Zirconia implants with two distinct surface topographies were compared withOBJECTIVE: This study aimed at evaluating the integration of zirconia implants in a rat femur model. MATERIAL AND METHODS: Zirconia implants with two distinct surface topographies were compared with titanium implants with similar topographies. Titanium and zirconia implants were placed into the femurs of 42 male Sprague-Dawley rats. Four groups of implants were utilized: machined zirconia implants, zirconia implants with a rough surface, machined titanium implants, and titanium implants with an electrochemically roughened surface. After a healing period of 28 days, the load-bearing capacity between the bone and the implant surface was evaluated by a push-in test. Additionally, after a healing period of 14 and 28 days, respectively, bone tissue specimens containing the implants were processed and histologically analyzed. RESULTS: The mean mineralized bone-to-implant contact showed the highest values after 14 and 28 days for the rough surfaces (titanium: 36%/45%; zirconia: 45%/59%). Also, the push-in test showed higher values for the textured implant surfaces, with no statistical significance between titanium (34 N) and zirconia (45.8 N). CONCLUSIONS: Within the limits of the animal investigation presented, it was concluded that all tested zirconia and titanium implant surfaces were biocompatible and osseoconductive. The presented surface modification of zirconia implants showed no difference regarding the histological and biomechanical results compared with an established electrochemically modified titanium implant surface.

• The biologic stability of alumina-zirconia implant abutments after 1 year of clinical service: a digital subtraction radiographic evaluation.

  Authors: Kyu-Hyun Bae, Jung-Suk Han, Yang-Jo Seol, Frank Butz, Jack Caton, In-Chul Rhyu

  The International journal of periodontics & restorative dentistry. 05/2008; 28(2):137-43.

  The purpose of the present clinical study was to evaluate the biologic stability of alumina-zirconia implant abutments by histologic and radiographic examination. Nineteen partially edentulousThe purpose of the present clinical study was to evaluate the biologic stability of alumina-zirconia implant abutments by histologic and radiographic examination. Nineteen partially edentulous patients were treated with 37 external-hexagon implants. After a healing period of 3 to 6 months, alumina-zirconia abutments were connected and restored with cemented single crowns or short-span fixed partial dentures. Periapical radiographs were taken at the time of prosthesis delivery and after 3, 6, and 12 months of follow-up. Crestal alveolar bone level changes were assessed by digital subtraction of consecutive images, and 1-way analysis of variance was used for statistical analysis. No implant, abutment, or restoration failed during the observation period. Bone level changes were statistically insignificant and histologic examination revealed no signs of inflammation. Stable and healthy soft and hard tissue conditions may be expected around alumina-zirconia abutments after 1 year of clinical service. However, long-term data are needed to confirm the present results.

• Ceramic abutments and ceramic oral implants. An update.

  Authors: Ralf J Kohal, Wael Att, Maria Bächle, Frank Butz

  Periodontology 2000. 02/2008; 47:224-43.

• Behavior of CAL72 osteoblast-like cells cultured on zirconia ceramics with different surface topographies.

  Authors: Maria Bächle, Frank Butz, Ute Hübner, Emmanouil Bakalinis, Ralf J Kohal

  Clinical oral implants research. 03/2007; 18(1):53-9.

  OBJECTIVES: Because of its inherent strength, biocompatibility, and tooth-like color, zirconia ceramics have the potential to become an alternative to titanium as dental implant material. This studyOBJECTIVES: Because of its inherent strength, biocompatibility, and tooth-like color, zirconia ceramics have the potential to become an alternative to titanium as dental implant material. This study aimed at investigating the osteoblastic response to yttrium-stabilized tetragonal zirconia polycrystal (Y-TZP) with different surface topographies. METHODS: CAL72 osteoblast-like cells were cultured on machined (TZP-m), airborne particle abraded (TZP-s), and airborne particle abraded and acid-etched Y-TZP (TZP-sa) surfaces. Polystyrene and airborne particle abraded with large grit and acid-etched (SLA) titanium served as a reference control. The surface topography was examined by scanning electron microscopy (SEM) and profilometry. At culture days 3, 6, and 12, cell proliferation, at day 12 cell morphology, and cell-covered surface area were determined. RESULTS: The surface roughness of Y-TZP was increased by airborne particle abrasion and additionally by acid etching. No statistically significant differences were found between average roughness (R(a)) and maximum peak-to-valley height (R(p-v)) values of airborne particle abraded and acid-etched Y-TZP and SLA titanium. Whereas the cell proliferation assay revealed statistically significant greater values at day 3 for surface-treated Y-TZP and polystyrene cultures as compared with machined Y-TZP, no differences between the Y-TZP groups, SLA titanium, and polystyrene were observed at culture days 6 and 12. CONCLUSIONS: Cell morphology and cell-covered surface area were not affected by the type of substrate. The results suggest that roughened Y-TZP is an appropriate substrate for the proliferation and spreading of osteoblastic cells.