Related Experiment Video
Updated: Feb 7, 2026
Bioelectric Analyses of an Osseointegrated Intelligent Implant Design System for Amputees
Published on: July 15, 2009
Daily melatonin administration improves osseointegration in pinealectomized rats
Letícia Pitol Palin1, Tarik Ocon Braga Polo2, Fábio Roberto de Souza Batista2
1Univ. Estadual Paulista, Faculdade de Odontologia, Departamento de Ciências Básicas, Araçatuba, São Paulo, Brasil.
Introduction:
The hypothesis of this study was that the peri-implant bone healing of the group of pinealectomized rats would differ from the control group. The samples were subjected to immunohistochemical, microtomographic (total porosity and connectivity density), and fluorochrome (mineralized surface) analyses.
Objectives:
The goal of this study was to investigate the cellular changes and bone remodeling dynamics along the bone/implant interface in pinealectomized rats.
Material And Methods:
The total of 18 adult male rats (Rattus norvegicus albinus, Wistar) was divided into three groups (n=6): control (CO), pinealectomized without melatonin (PNX) and pinealectomized with melatonin (PNXm). All animals were submitted to the first surgery (pinealectomy), except the CO group. Thirty days after the pinealectomy without melatonin, the second surgery was conducted, in which all animals received an implant in each tibia (36 titanium implants with surface treatment were installed - Implalife® São Paulo, SP, Brazil). By gavage, the rats of the PNX group received the vehicle solution, and the procedure.
Results:
Immunohistochemical analysis for runt-related transcription factor 2 (RUNX2), alkaline phosphatase (ALP), osteopontin (OP) and osteocalcin (OC) showed that the bone repair process in the PNXm group was similar to that of the CO group, whereas the PNX group showed a delay. The microtomographic parameters of total porosity [Po(tot)] and bone surface (BS) showed no statistically significant differences, whereas for the connective density (Conn.Dn) a statistical difference was found between the CO and PNXm groups. Fluorochrome analysis of the active mineralized surface showed statistically significant difference between the CO and PNX and between the CO and PNXm groups.
Conclusion:
The absence of the pineal gland impaired the bone repair process during osseointegration, however the daily melatonin replacement was able to restore this response.
Related Concept Videos
01:17Classical Conditioning in Daily Life
John B. Watson and Rosalie Rayner famously demonstrated the development of fear through classical conditioning in their experiment with Little Albert. They paired the...
02:07Improving Translational Accuracy
02:07Improving Translational Accuracy
01:18Additional Routes of Drug Administration
Administering drugs via inhalation allows for the direct delivery of gaseous, volatile substances or droplets to different parts of the respiratory tract. One of the advantages of the inhalation route is the rapid absorption of drugs into the circulatory system, which is possible because of the large surface area of...
01:18Routes of Drug Administration: Enteral
Enteral administration involves drug administration via the mouth in two ways: orally or sublingually.
Unlike sublingually drugs, drugs that are taken orally pass through the gastrointestinal (GI) tract and get metabolized by the liver. Once metabolized, the drug is absorbed into the systemic circulation, reaching different body parts via the bloodstream. However, while passing through the stomach,...
01:25Routes of Drug Administration: Parenteral
The intravenous route (IV) of drug administration can be further categorized into two types. The bolus injection administers the entire dose rapidly, while an intravenous infusion slowly delivers smaller doses steadily.
The IV route is often...