Effects of Bioabsorbable and Non‐Resorbable Barrier Membranes on Bone Augmentation in Rabbit Calvaria

Abstract

The aim of this study was to compare the effects of bioabsorbable and non-resorbable membranes on experimental guided bone augmentation in 8 Japanese white rabbits. A cutaneous flap was demarcated and raised from the forehead of each animal, the periosteum was lifted, and the calvarial bone on both sides of the midline was exposed. A titanium screw was inserted into the bone on each side of the midline and one screw was covered with a bioabsorbable (polylactic acid) membrane and the other with a non-resorbable (expanded polytetrafluoroethylene) membrane. The implanted screws and membranes were then covered with the periosteum and cutaneous flap. After healing for 6 months, the animals were euthanized and the experimental area was prepared for histological investigation. New bone had formed under both membranes with no sign of infection or membrane exposure. The amount of newly generated bone (89.0 +/- 17.3% versus 54.7 +/- 14.0%, P <0.05) and the percentage of newly generated bone height (81.5 +/- 6.3% versus 58.9 +/- 7.8%, P <0.05) in the space beneath the non-resorbable membrane was greater than that beneath the bioabsorbable membrane. However, there were no statistically significant differences between the bioabsorbable and non-resorbable membranes with respect to the percentage areas of mineralized bone (52.3 +/- 11.3% versus 47.1 +/- 6.7%, P = 0.8658) and bone marrow (47.7 +/- 11.3% versus 52.9 +/- 6.7%, P = 0.4838) and bone contact with the screw (88.3 +/- 6.9% versus 89.2 +/- 7.3%, P = 0.9999). In conclusion, at least within the limitations of this rabbit model, we suggest that non-resorbable membranes with sufficient stiffness should be used to obtain greater bone volume and height instead of bioabsorbable membranes for the GBR procedure, and that this will facilitate predictable bone augmentation in spaces beyond the bone surface. Therefore, the bioabsorbable membrane could not replace the non-resorbable membrane used in this model.

Selective laser-melted fully biodegradable scaffold composed of poly(d,l-lactide) and β-tricalcium phosphate with potential as a biodegradable implant for complex maxillofacial reconstruction:In vitroandin vivoresults

“…MSCs were grown in 96-well pates for 20 days, and the medium was changed every 2 days. Subsequently, the culture medium was replaced by 100 mL particle suspension at concentrations of 4, 10, 25, 50, and 100 lg/mL of the medium control and 5 lg/mL peptide control, and the cells were exposed for 4,6,8,24,30, and 48 h. Afterwards, 20 mL CTB (Promega) was added to each well and incubated for 1.5 h. Fluorescence was read at excitation/emission wavelengths of 540/590 nm in a FLUO-STAR plate reader (BMG, Germany). Cell proliferation rate was measured at day 1, 3, 7, 10, 14, 17, and 21.…”

“…4 The degradation of these polymers has been widely investigated in vitro 5 and in vivo. 6 One remaining problem of polymer use in vivo is the acidic environment adjacent to the implant site caused by a resorption process involving the hydrolytic dissociation of the lactic structure out of the polymer. An acidic environment results in inflammatory tissue reactions and prevents the full degradation of the implant.…”

Molded porous poly (L-lactide) membranes for guided bone regeneration with enhanced effects by controlled growth factor release

“…39 Some biodegradable membranes have failed in bone regenerative therapy due to insufficient space maintenance followed by rapid degradation. 9,40 Biodegradable membranes need to maintain their integrity during the bone regenerating period and then gradually degrade. In this respect, PLLA-TCP membranes may be suitable, as they maintained their integrity during the bone regenerating period while allowing gradual degradation.…”

“…[1][2][3][4][5][6] These membranes have been explored for use in bone augmentation even in complicated and localized bone defects, i.e., alveolar ridge defects and lower skeletal borders, though they have limitations in providing space and maintaining properties that are essential for predictable bone regeneration. [7][8][9][10][11][12] In most bone augmentations, bone defect sites usually are localized below the original bone surface; therefore, space creation and maintenance between the membrane and the original bone surface is crucial. 7,8 Space provision by the membrane is essential for withstanding forces exerted by the overlying flaps, preventing the collapse of the soft tissue, and maintaining wound space that permits alveolar bone growth.…”

“…7,8 Space provision by the membrane is essential for withstanding forces exerted by the overlying flaps, preventing the collapse of the soft tissue, and maintaining wound space that permits alveolar bone growth. 9,[13][14][15] Several attempts have been made to provide bone-forming space with particular defects by using reinforced membranes. 16,17 For example, stiffer or more rigid membranes reinforced by metal or ceramics have been investigated for their moldability, including space providing ability.…”