- Email: [email protected]
SEM observation of angiogenesis around hydroxyapatite using vascular corrosion casts
021-C1 Dento-alveolar surgery & Laser surgery & Preprosthetic surgery and implantology thesis of ALA is regulated by feedback control. When exogenous A L A is administered, the feedback control mechanism can be bypassed and induces accumulation of photosensitive protoporphyrina. The application of ALA is based on this mechanism. PDT using ALA has advantages such as short sensitizer half life, the absence of prolonged skin photosensitivity and topical applicability. We have studied the photodynamic effct of A L A on cultured HeLa cells in vitro. YAG-dye-laser was used as a light source. The cytotoxic effect and apoptosis of the cells were investigated in this study.
11. Factors Affecting the Antibacterial Effects of Nd: YAG Laser in Vivo
53
placed, the defects 2, 4, 8, 12 weeks after operation showed osseous regeneration but the thickness was much less than the original bone. Resorption of polyglactin 910 mesh was completed after 4 weeks. 2. In group 2, where fascia lata had been placed, the defects 2, 4, 8, 12 weeks after operation showed the same pattern as group 1. 3. In group 3 and 4, where a membrane had not been placed, the majority of the defects consisted of connective tissue and muscles.
13. SEM Observation of Angiogenesis around Hydroxyapatite Using Vascular Corrosion Casts
Chang, C. S. 1, Lin, T. C), Su, C. y2 Tasar, E l, Sener, B. (7.1, Ceritoglu, G), Kocagoz, S. 2 1Department of Oral Surgery, Faculty of Dentistry, 2 Department of Internal Diseases, Fac. of Medicine, Unit of Injection, Hacettepe Univ., Ankara, Turkey With its vaporization effect N d : Y A G laser provides sterilization of the oral mucosa. The aim of this., experimental study was to evaluate the factors that may affect the antibacterial effect of N d : Y A G laser on Staphylococcus aureus. The colour density of the cultivation media, quantification of the bacteria and dosage of the laser exposure were variables involved. Prior studies have used suomi ink, which normally is not present in the tissue, to increase the effectiveness of N d : Y A G laser in vivo. In our study horse erytrocyte suspension in different concentrations was used to determine the colour density. This way a colour standardization for the cultivation media could be established. Several bacterial suspensions (104, 106, 108) of S. aureus were studied. The distance between laser source and suspensions were kept constant by means of a simple fiber tip 'holder. With various energy levels and exposure times the bacterial suspensions were treated. A control group was also prepared from non-irradiated bacteria suspensions to observe normal bacterial growth. The samples were spread on Columbia agar plates and incubated for 12 hours. The c010nised units were counted. This way minimal antibacterial radiation levels of Nd: YAG laser for S. aureus were caIculated.
12. Guided Bone Regeneration of Cranial Defects using Various Membranes: An Experimental Study in Rabbits
Son, J.-H., Kim, J.-R. Department of Oral and Maxillofacial Surgery, Dental College, Pusan National University, Pusan, Ki)rea This study was designed to examine the effect of polyglactin 910 mesh and autogenous fascia lata transplants as membranes to guide bone regeneration. The results were as follows: 1. In group 1, where polyglactin 910 mesh had been
1Department of Oral and Maxillofacial Surgery, Veterans General Hospital-Taipei, 2School of Dentistry, National Yang-Ming University, Taiwan An intimate relationship exists between osteogenesis and angiogenesis following hydroxyapatite (HA) implantation. In order to fully understand the three-dimensional vascular arch itecture aroun d HA, dense HA particles were implanted into the tibiae of dogs and the corrosion cast technique was used for the specimen preparation. Under scanning electron microscope (SEM) observation, the characteristic vascular changes of the HA-implanted cavity were successfully demonstrated. The initial angiogenesis took the form of sinusoidal capillaries. Many sinusoids formed a complex threedimensional network by anastomosing with each other. The newly-formed vessels extend centripetally from the peripheral cavity wall and from the periosteal surface. Under greater magnification, the tapered vascular sprouting was shown to project into the space which was previously occupied by a HA particle. With increasing implantation time, peri-particle vessels exhibited smooth curves, usually parallel the HA surface. The vascular organizational layout of the cavity was also clearly shown in the cross-section. Radially directed vessels were believed to be compatible with vessels within the Haversian's canal, indicating the more complicated organization of the vascular system. In the control group that did not implant HA, .the central region of the cavity showed a concave vascular pattern in the initial stage. The vascularization looked like collapsing without fully filling the cavity. The concave area was supposed to be occupied previously by the fibrous connective tissue, which was digested during the specimen processing. This study provided the serial three-dimensional vascular changes of HA-implanted cavity as well as the value of corrosion cast technique in examining the bony circulation.
11. Factors Affecting the Antibacterial Effects of Nd: YAG Laser in Vivo
53
placed, the defects 2, 4, 8, 12 weeks after operation showed osseous regeneration but the thickness was much less than the original bone. Resorption of polyglactin 910 mesh was completed after 4 weeks. 2. In group 2, where fascia lata had been placed, the defects 2, 4, 8, 12 weeks after operation showed the same pattern as group 1. 3. In group 3 and 4, where a membrane had not been placed, the majority of the defects consisted of connective tissue and muscles.
13. SEM Observation of Angiogenesis around Hydroxyapatite Using Vascular Corrosion Casts
Chang, C. S. 1, Lin, T. C), Su, C. y2 Tasar, E l, Sener, B. (7.1, Ceritoglu, G), Kocagoz, S. 2 1Department of Oral Surgery, Faculty of Dentistry, 2 Department of Internal Diseases, Fac. of Medicine, Unit of Injection, Hacettepe Univ., Ankara, Turkey With its vaporization effect N d : Y A G laser provides sterilization of the oral mucosa. The aim of this., experimental study was to evaluate the factors that may affect the antibacterial effect of N d : Y A G laser on Staphylococcus aureus. The colour density of the cultivation media, quantification of the bacteria and dosage of the laser exposure were variables involved. Prior studies have used suomi ink, which normally is not present in the tissue, to increase the effectiveness of N d : Y A G laser in vivo. In our study horse erytrocyte suspension in different concentrations was used to determine the colour density. This way a colour standardization for the cultivation media could be established. Several bacterial suspensions (104, 106, 108) of S. aureus were studied. The distance between laser source and suspensions were kept constant by means of a simple fiber tip 'holder. With various energy levels and exposure times the bacterial suspensions were treated. A control group was also prepared from non-irradiated bacteria suspensions to observe normal bacterial growth. The samples were spread on Columbia agar plates and incubated for 12 hours. The c010nised units were counted. This way minimal antibacterial radiation levels of Nd: YAG laser for S. aureus were caIculated.
12. Guided Bone Regeneration of Cranial Defects using Various Membranes: An Experimental Study in Rabbits
Son, J.-H., Kim, J.-R. Department of Oral and Maxillofacial Surgery, Dental College, Pusan National University, Pusan, Ki)rea This study was designed to examine the effect of polyglactin 910 mesh and autogenous fascia lata transplants as membranes to guide bone regeneration. The results were as follows: 1. In group 1, where polyglactin 910 mesh had been
1Department of Oral and Maxillofacial Surgery, Veterans General Hospital-Taipei, 2School of Dentistry, National Yang-Ming University, Taiwan An intimate relationship exists between osteogenesis and angiogenesis following hydroxyapatite (HA) implantation. In order to fully understand the three-dimensional vascular arch itecture aroun d HA, dense HA particles were implanted into the tibiae of dogs and the corrosion cast technique was used for the specimen preparation. Under scanning electron microscope (SEM) observation, the characteristic vascular changes of the HA-implanted cavity were successfully demonstrated. The initial angiogenesis took the form of sinusoidal capillaries. Many sinusoids formed a complex threedimensional network by anastomosing with each other. The newly-formed vessels extend centripetally from the peripheral cavity wall and from the periosteal surface. Under greater magnification, the tapered vascular sprouting was shown to project into the space which was previously occupied by a HA particle. With increasing implantation time, peri-particle vessels exhibited smooth curves, usually parallel the HA surface. The vascular organizational layout of the cavity was also clearly shown in the cross-section. Radially directed vessels were believed to be compatible with vessels within the Haversian's canal, indicating the more complicated organization of the vascular system. In the control group that did not implant HA, .the central region of the cavity showed a concave vascular pattern in the initial stage. The vascularization looked like collapsing without fully filling the cavity. The concave area was supposed to be occupied previously by the fibrous connective tissue, which was digested during the specimen processing. This study provided the serial three-dimensional vascular changes of HA-implanted cavity as well as the value of corrosion cast technique in examining the bony circulation.