One of the primary causes for the failure of glass ionomer cement (GIC) is secondary caries. To enhance the anti-microbial performance of GIC without affecting its mechanical properties, chlorhexidine (CHX) was encapsulated in expanded-pore mesoporous silica nanoparticles (pMSN) to synthesize CHX@pMSN. CHX@pMSN was added at three mass fractions (1%, 5%, and 10% (w/w)) to GIC powder as the experimental groups. Pure GIC was set as the control group. The mechanical and anti-biofilm properties of GIC from each group were tested. The results demonstrated that CHX was successfully encapsulated on/into pMSN, and the encapsulating efficiency of CHX was 44.62% in CHX@pMSN. The anti-biofilm ability was significantly enhanced in all experimental groups (p < 0.001) compared with that in the control group. CHX was continuously released, and anti-biofilm ability was maintained up to 30 days. In addition, the mechanical properties (compressive strength, surface hardness, elastic modulus, water sorption, and solubility) of 1% (w/w) group were maintained compared with those in the control group (p > 0.05). In conclusion, adding 1% (w/w) CHX@pMSN to GIC led to conspicuous anti-biofilm ability and had no adverse effect on the mechanical properties of this restorative material. This study proposes a new strategy for preventing secondary caries by using CHX@pMSN-modified GIC.

This study evaluates and compares the mechanical behavior of two collagen membranes in an in vitro model simulating membrane-stabilized horizontal guided bone regeneration (GBR). Megreen^® (bovine pericardium, BP) and Bio-Gide^® (porcine dermis, PD) were tested under wet conditions. Two models were developed: (1) a balloon dilation test to assess the membrane's capability to accommodate bone graft material and (2) a bone graft compression model to evaluate tear resistance during graft compaction. In the tensile testing, BP demonstrated a significantly superior modulus of elasticity (146.71 ± 45.08 vs. 6.08 ± 2.66 MPa), maximum load tolerance (30.71 ± 8.42 vs. 4.49 ± 1.36 N), and tensile stress at maximum load (14.62 ± 4.01 vs. 1.61 ± 0.49 MPa; p < 0.001). Conversely, PD achieved high tensile extension at maximum load (6.32 ± 1.93 vs. 1.64 ± 0.32 mm) and percent tensile strain at maximum load (52.69 ± 16.03 vs. 13.63 ± 2.65%; p < 0.001). In the balloon dilation test, PD presented a slightly greater expansion diameter (4.43 ± 0.17 vs. 4.34 ± 0.05 mm; p = 0.047). In the compression model, BP significantly outperformed PD in maximum load (40.86 ± 4.54 vs. 7.90 (7.72-10.92) N) and displacement at maximum load (5.61 ± 0.60 vs. 3.65 ± 0.82 mm; p < 0.001). BP exhibited higher tensile strength and compression resistance, whereas PD showed greater deformability. These findings indicate distinct mechanical differences between the two collagen membranes under the tested conditions and may provide a mechanical basis for membrane selection in membrane-stabilized horizontal GBR.