Could Calcified Triglyceride Bone Cement Be an Alternative Graft Material in Maxillary Sinus Augmentation?

Fish: a new xenograft source for maxillary sinus lifting

OBJECTIVE

Although autogenous grafting is accepted as the gold standard in intraoral grafting, xenogenous grafts are frequently used in sinus lift surgeries due to their osteoinductive and osteoconductive properties. This study aimed to investigate the efficacy of fish spine-derived xenogenic grafts in sinus augmentation surgery.

MATERIAL AND METHODS

In this study, a fish spine-derived xenogenic graft was produced for comparison with autogenous graft and bovine derived xenogenic grafts. Twenty-one New Zealand rabbits were used. Autogenous grafts (AG- Group 1), as well as bovine-derived (bHAP - Group 2) and fish spine-derived (fHAP - Group 3) xenogenic grafts were placed in the right and left sinuses of rabbits. The animals were sacrificed at the 4th and 8th weeks. New bone formation (NBF) was evaluated through histological examination, while bone volume (BV), new bone surface/bone volume (BS-BV), new bone surface/tissue volume (BS-TV), and trabecular separation (Tb-Sp) were assessed via Micro-CT. Statistical significance was considered at p<0.05.

RESULTS

Histological examination revealed a significant difference in NBF between AG-bHAP (p<0.001), as well as between fHAP-bHAP (p<0.001) in the fourth-week group. No significant difference was found in the eighth-week group (p=0.130). In the eighth-week group, a statistically significant difference was found between fHAP and bHAP in terms of BV. (p=0.007).

CONCLUSION

Although both graft materials used in this study showed positive effects on bone regeneration, fHAP and AG presented similar effects on bone regeneration and were superior to bHAP.

A stereological study of the effects of mercury inhalation on the cerebellum

Mercury in the environment that arises from organic and inorganic sources can cause irreversible damage to the nervous system. Toxicity may be direct or may arise from interactions with other metals in the environment. We evaluated the possible effects of mercury vapor on rat cerebellum. Twelve adult female rats were divided into control and experimental groups. The rats in the experimental group were exposed to mercury vapor for 9 h/day for 45 days. Cerebellar tissue samples were evaluated using stereology and for histopathology. The total number of Purkinje cells was estimated using a physical disector method. We found that in the experimental group, overall volume decreased and the number of Purkinje cells was reduced. We also found cellular damage including pycnotic nuclei, eosinophilic cytoplasm and vacuolization; these features were absent in the control group. We found that chronic exposure to inorganic mercury vapor is toxic to the cerebellum.