----- Meeting Notes (10/7/12 23:30) -----well known researchers in implant surface studies
----- Meeting Notes (10/7/12 23:30) -----this study was investigatiing by doing histomorphometric analysis of 3 defined surfaces.all the screws were----- Meeting Notes (10/8/12 08:47) -----short term follow up
----- Meeting Notes (10/7/12 23:40) -----osseoinegration: direct implant bone contact even in hitological level.not only implant stability and enchorag by bone.
----- Meeting Notes (10/7/12 23:40) -----some studies specify the degree of roughness to be a moderate roughness
----- Meeting Notes (10/7/12 23:40) -----the rabbits: same type,size, age with most of studies.also screw diameters. same other studies.
----- Meeting Notes (10/7/12 23:40) -----one of most common techniques:modification.----- Meeting Notes (10/7/12 23:44) -----TiO2), which stimulates osteointegration and prevents migration of metal ions and microsubstances into the body.----- Meeting Notes (10/7/12 23:46) -----Al2O3 will show also the same good biocompatibility
----- Meeting Notes (10/7/12 23:48) -----profilometer :measure a surface's profile, in order to quantify its roughness.
----- Meeting Notes (10/7/12 23:54) -----these 7 prameters are for numerical discription.the first 5 are for hight description.the last 2 for hight and space----- Meeting Notes (10/8/12 00:04) -----give numerical values and idea about the degree of surface roughness.
----- Meeting Notes (10/8/12 00:07) -----same location used.the average thickness of cortex bone used in rabbits is about 1-1.25 mm.with low speed rotary instruments, saline irrigation.
----- Meeting Notes (10/8/12 00:11) -----same as mentioned in other studies
----- Meeting Notes (10/8/12 00:11) -----they didnt expect that. its the oppsite direction of ther results like removal torque and BIC
A histomorghometric study of screw-shaped and removal torque titanium implants with three different surface topographies
A histomorghometric study of screw-shaped and removal torque titaniumimplants with three different surface topographies ALI ALENEZI
The authors• A. Wennerberg, T. Albrektsson, B. Andersson, J. J. Krol.• Published by: Clinical Oral Implants Research Volume 6, Issue 1, pages 24–30, March 1995
The aim of the study:To investigate bone response in relation to well definedsurface over short time of follow-up. Blasted with TiO2 Turned surface 25µm particles Blasted with Al2O3 75µm particles
Surface quality One of the six factors that influence the biological response to implant ( alberktsson et al. 1981) Surface qualityThe remaining 5 factors:• Implant biocompatibility Loading Implant biocompatib conditions ility• Implant design• State of host bed Osseointegration• Surgical Technique Surgical Implant Technique design• Loading conditions State of host bed
The concept of surface qualityIt includes: All Surface properties (mechanical, physical, chemical, topographical). The influence of surface quality on implant integration investigated in many studies at that time (1980s &1990s).
Implant surface roughness- better bone-forming capability around rough implant incompared with smooth ones ( carlsson et al. 1988).The suggested explanations:1- more advantageous stress transfer.2- better mechanical interlocking (kasemo 1983).
Materials and methods The implant have been characterized in to 3 different topographies. 10 new Zealand rabbits. 60 screw shaped commercially pure titanium. Implants length; 6mm, diameter: 3.75, pitch height: 0.6mmSurface topography Number of implantsTurned surface 30Blasted with TiO2 particles, with a diameter 25µm 20Blasted with Al2O3 particles, with a diameter 75µm 10
The blasting processBasic due(renfert, Germany)After blasting process, allthe implants cleanedultrasonically intrichloroethylene and 70%ethanol
Surface topography examinationOptical profilometer, topscan 3D . Non contact mode Visual images Numerical values for surface roughness. 240x245 μm measurement area
Surface roughness parameters In this paper, 7 different height parameters used to describe the roughness.Ra The arithmetic mean of departures of the roughness profile from the mean linesRq the root mean square parameter corresponding to RaRt the maximum peak to valley height in the evaluation areaRsk The measures of the symmetry of the profileRku The measures of the sharpness of the surface profile.∆q the root mean square slope of the surfaceπq the root mean square measure of spacings between local peaks and valleys
Surgical technique1 rabbit = 6 implants RIGHT LEFT FEMUR Al2O3 turned PROXIMAL TiO2 turned TIBIA DISTAL TIBIA TiO2 turned
Torque measurement andhistomorphometrical analysisFor torque measurement: 40 implants (20 from femur and 20 from distal tibia). Slowly increasing torque was gradually applied until loosening of implant.For histomorphometrical analysis: 20 implants ( proximal tibia) Cutting & grinding by (Exakt equipments) 10 μm section thickness. To measure: 1- % bone to metal contact. 2- The amount of bone area.
ResultsTurned screws : exhibited the smoothest surface Surface with clear direction of irregularities.Screws blasted with TiO2: More homogenous surface. Increased roughness.Screws blasted with Al2O3: the roughest surface. homogenous surface.
ResultsThe blasting procedure was responsible fordecreasing the (outer &core) diameter of implants
Results Removal torque values necessary to remove the screws after 12 weeks:In femur:Screw blasted with Al2O3 > turned.In tibia:Screw blasted with TiO2 > turned.
ResultsHistomorphometric analysis:- Bone metal contact % :Higher for TiO2 25-µmimplants comparedwith turned implants.
Results Histomorphometric analysis:- Bone surface area:Greater bone area for turnedimplants when compared with TiO2-blasted implants
discussion The implants that been treated with blasting procedures show higher removal torque values and higher percentage of contact bone to the metal surface.On the other hand,,, Turned implants had more bone surface area after 12 weeks.
In this study: The same surgical instrument were used for all implants, which not have the same exact diameter (the blasting process cause a minor reduction). But, the blasted implants showed better interfacial healing response. Furthermore, we have different surface irregularities between blasted and turned implants. Its short term results. Not to be generalized especially For clinical reality.