En kelator er et medikament som er beregnet på å behandle tungmetallforgiftning, men kelatorer («... more En kelator er et medikament som er beregnet på å behandle tungmetallforgiftning, men kelatorer («Dimavaltest») brukes av enkelte for å belyse helseproblemer forbundet med amalgam i tennene («amalgamsykdom») Diagnostisk bruk av kelator øker kvikksølvutskillingen i urin raskt og forbigående til 20 – 30 ganger i forhold til uprovoserte verdier, mest hos personer med amalgam i tennene Det er ingen aksepterte grenseverdier for verdier oppnådd ved kelatortesting. Sammenlikning med uprovoserte grenseverdier er ikke relevant Den diagnostiske verdien av kelatortester er liten fordi kvikksølvmålingene i hovedsak reflekterer mengden av amalgam i tennene
The aim of the study was to compare side-to-side with step-cut repairs to determine how much of t... more The aim of the study was to compare side-to-side with step-cut repairs to determine how much of the width it is possible to remove and still keep the repair strong enough to start active mobilization. Porcine flexor tendons were used to create side-to-side, one-third step-cut and half step-cut repairs. There were 15 repairs in each group. The tensile properties of the constructs were measured in a biomechanical testing machine. All repairs failed by the sutures splitting the tendon longitudinally. The maximum load and stiffness were highest in the side-to-side group. Our findings suggest that the half step-cut repair can withstand the forces exerted during active unrestricted movement of the digits in tendons of this size. The advantage of the step-cut repair is reduced bulkiness and less friction, which might compensate for the difference in strength.
The aim of the study was to present two new modifications of the Pulvertaft weave, allowing a hig... more The aim of the study was to present two new modifications of the Pulvertaft weave, allowing a higher number of weaves without the need for a longer overlap. The mechanical properties were measured and compared with the traditional technique. Forty-five pairs of porcine flexor tendons were randomized to a Pulvertaft repair with three weaves, a Double Pulvertaft and Locking Pulvertaft repairs. In the last two repairs one of the tendons in each repair was split in two before weaving. A difference in the maximum stiffness was observed between the three groups ( p = 0.024). All repairs failed by the sutures being sheared through the tendons splitting the tendon fibres longitudinally. The two modifications were both stronger than the Pulvertaft weave and provide an alternative when a strong connection is needed and a longer overlap is impossible.
The effect of anatomic contour design in all or parts of zirconia crowns is uncertain regarding c... more The effect of anatomic contour design in all or parts of zirconia crowns is uncertain regarding clinical reliability and survival rates. The purpose of this in vitro study was to compare the load at fracture of monolithic, anatomic contour zirconia crowns with bilayered crowns with and without a cervical zirconia collar. Thirty zirconia crowns were fabricated for a shallow chamfer molar preparation, 10 with a normal core-veneer design, 10 with a core-veneer design with an additional cervical collar of zirconia, and 10 with a monolithic, anatomic contour design. Veneering ceramic was applied to the first 20 specimens to create an anatomic form. All crowns were cemented to epoxy abutments and loaded until complete fracture with a clinically relevant test method. The fracture modes and load at fracture were recorded. Statistically significant differences were found in the load at fracture and fracture modes among the test groups (P<.001). All fractures except one initiated in the cr...
Fractures during clinical function have been reported as the major concern associated with all‐ce... more Fractures during clinical function have been reported as the major concern associated with all‐ceramic dental restorations. The aim of this study was to analyze the fracture features of glass‐ceramic and zirconia‐based restorations fractured during clinical use. Twenty‐seven crowns and onlays were supplied by dentists and dental technicians with information about type of cement and time in function, if available. Fourteen lithium disilicate glass‐ceramic restorations and 13 zirconia‐based restorations were retrieved and analyzed. Fractographic features were examined using optical microscopy to determine crack initiation and crack propagation of the restorations. The material comprised fractured restorations from one canine, 10 incisors, four premolars, and 11 molars. One crown was not categorized because of difficulty in orientation of the fragments. The results revealed that all core and veneer fractures initiated in the cervical margin and usually from the approximal area close to...
The right femur in 40 rats was reamed, and in 40 others it was additionally nailed. Analysis of b... more The right femur in 40 rats was reamed, and in 40 others it was additionally nailed. Analysis of bone blood flow was performed by the distribution of radiolabeled microspheres at different postoperative time intervals. Blood-flow measurements were accompanied by analyses of hydroxyproline and calcium contents. Immediately after reaming, the blood flow of the diaphyseal part of the femur was reduced to approximately one third of that of the intact femur, whereas the contents of hydroxyproline and calcium were reduced by 10 percent. Within 1 week, the blood flow was normal. This study provides evidence that the presence of a nail does not interfere with the restoration of bone blood flow. Restoration of blood flow in bone apparently is a rapid process. The replacement of hydroxyproline and calcium contents seemed to be linked to flow, as no increase in these constituents were found until the blood flow had approximated the level of the intact femur.
Veterinary and Comparative Orthopaedics and Traumatology, 2012
SummaryObjective: Prosthetic elements must be securely anchored to bone. Should revision surgery ... more SummaryObjective: Prosthetic elements must be securely anchored to bone. Should revision surgery be necessary, preservation of bone stock is crucial. The goal of this study was to develop and assess a femoral stem combining secure anchorage and facilitated removal in a goat model.Methods: The development of the uncemented femoral stem was part of an innovation process to fulfill the combined requirements. The stem was designed with two longitudinal semicircular grooves to accommodate a drill bit to unanchor the stem. These grooves were interconnected by canals, each 1 mm in diameter. The surface was partly coated with hydroxyapatite (HA). The stems were inserted in the left hip of 35 goats. Perioperatively, the grooves were filled with autologous bone grafts, and standard cemented canine acetabular component and head were used. The pull-out force was measured six months postoperatively. Following randomization, 11 animals had the grooves of the stem drilled to remove anchoring tissu...
En kelator er et medikament som er beregnet på å behandle tungmetallforgiftning, men kelatorer («... more En kelator er et medikament som er beregnet på å behandle tungmetallforgiftning, men kelatorer («Dimavaltest») brukes av enkelte for å belyse helseproblemer forbundet med amalgam i tennene («amalgamsykdom») Diagnostisk bruk av kelator øker kvikksølvutskillingen i urin raskt og forbigående til 20 – 30 ganger i forhold til uprovoserte verdier, mest hos personer med amalgam i tennene Det er ingen aksepterte grenseverdier for verdier oppnådd ved kelatortesting. Sammenlikning med uprovoserte grenseverdier er ikke relevant Den diagnostiske verdien av kelatortester er liten fordi kvikksølvmålingene i hovedsak reflekterer mengden av amalgam i tennene
The aim of the study was to compare side-to-side with step-cut repairs to determine how much of t... more The aim of the study was to compare side-to-side with step-cut repairs to determine how much of the width it is possible to remove and still keep the repair strong enough to start active mobilization. Porcine flexor tendons were used to create side-to-side, one-third step-cut and half step-cut repairs. There were 15 repairs in each group. The tensile properties of the constructs were measured in a biomechanical testing machine. All repairs failed by the sutures splitting the tendon longitudinally. The maximum load and stiffness were highest in the side-to-side group. Our findings suggest that the half step-cut repair can withstand the forces exerted during active unrestricted movement of the digits in tendons of this size. The advantage of the step-cut repair is reduced bulkiness and less friction, which might compensate for the difference in strength.
The aim of the study was to present two new modifications of the Pulvertaft weave, allowing a hig... more The aim of the study was to present two new modifications of the Pulvertaft weave, allowing a higher number of weaves without the need for a longer overlap. The mechanical properties were measured and compared with the traditional technique. Forty-five pairs of porcine flexor tendons were randomized to a Pulvertaft repair with three weaves, a Double Pulvertaft and Locking Pulvertaft repairs. In the last two repairs one of the tendons in each repair was split in two before weaving. A difference in the maximum stiffness was observed between the three groups ( p = 0.024). All repairs failed by the sutures being sheared through the tendons splitting the tendon fibres longitudinally. The two modifications were both stronger than the Pulvertaft weave and provide an alternative when a strong connection is needed and a longer overlap is impossible.
The effect of anatomic contour design in all or parts of zirconia crowns is uncertain regarding c... more The effect of anatomic contour design in all or parts of zirconia crowns is uncertain regarding clinical reliability and survival rates. The purpose of this in vitro study was to compare the load at fracture of monolithic, anatomic contour zirconia crowns with bilayered crowns with and without a cervical zirconia collar. Thirty zirconia crowns were fabricated for a shallow chamfer molar preparation, 10 with a normal core-veneer design, 10 with a core-veneer design with an additional cervical collar of zirconia, and 10 with a monolithic, anatomic contour design. Veneering ceramic was applied to the first 20 specimens to create an anatomic form. All crowns were cemented to epoxy abutments and loaded until complete fracture with a clinically relevant test method. The fracture modes and load at fracture were recorded. Statistically significant differences were found in the load at fracture and fracture modes among the test groups (P<.001). All fractures except one initiated in the cr...
Fractures during clinical function have been reported as the major concern associated with all‐ce... more Fractures during clinical function have been reported as the major concern associated with all‐ceramic dental restorations. The aim of this study was to analyze the fracture features of glass‐ceramic and zirconia‐based restorations fractured during clinical use. Twenty‐seven crowns and onlays were supplied by dentists and dental technicians with information about type of cement and time in function, if available. Fourteen lithium disilicate glass‐ceramic restorations and 13 zirconia‐based restorations were retrieved and analyzed. Fractographic features were examined using optical microscopy to determine crack initiation and crack propagation of the restorations. The material comprised fractured restorations from one canine, 10 incisors, four premolars, and 11 molars. One crown was not categorized because of difficulty in orientation of the fragments. The results revealed that all core and veneer fractures initiated in the cervical margin and usually from the approximal area close to...
The right femur in 40 rats was reamed, and in 40 others it was additionally nailed. Analysis of b... more The right femur in 40 rats was reamed, and in 40 others it was additionally nailed. Analysis of bone blood flow was performed by the distribution of radiolabeled microspheres at different postoperative time intervals. Blood-flow measurements were accompanied by analyses of hydroxyproline and calcium contents. Immediately after reaming, the blood flow of the diaphyseal part of the femur was reduced to approximately one third of that of the intact femur, whereas the contents of hydroxyproline and calcium were reduced by 10 percent. Within 1 week, the blood flow was normal. This study provides evidence that the presence of a nail does not interfere with the restoration of bone blood flow. Restoration of blood flow in bone apparently is a rapid process. The replacement of hydroxyproline and calcium contents seemed to be linked to flow, as no increase in these constituents were found until the blood flow had approximated the level of the intact femur.
Veterinary and Comparative Orthopaedics and Traumatology, 2012
SummaryObjective: Prosthetic elements must be securely anchored to bone. Should revision surgery ... more SummaryObjective: Prosthetic elements must be securely anchored to bone. Should revision surgery be necessary, preservation of bone stock is crucial. The goal of this study was to develop and assess a femoral stem combining secure anchorage and facilitated removal in a goat model.Methods: The development of the uncemented femoral stem was part of an innovation process to fulfill the combined requirements. The stem was designed with two longitudinal semicircular grooves to accommodate a drill bit to unanchor the stem. These grooves were interconnected by canals, each 1 mm in diameter. The surface was partly coated with hydroxyapatite (HA). The stems were inserted in the left hip of 35 goats. Perioperatively, the grooves were filled with autologous bone grafts, and standard cemented canine acetabular component and head were used. The pull-out force was measured six months postoperatively. Following randomization, 11 animals had the grooves of the stem drilled to remove anchoring tissu...
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