Topical application of melatonin and growth hormone accelerates bone healing around dental implants in dogs.
BACKGROUND
Growth hormone (GH) and melatonin belong to the group of growth factors. These substances have been proposed to improve and accelerate osseous healing using topical applications.


OBJECTIVE
The aim of this study was to evaluate the effect of the topical administration of GH and melatonin on osseointegration of dental implants in Beagle dogs 2, 5, and 8 weeks after their insertion.


METHODS
Twelve adult Beagle dogs and 48 implants were used in the study. The maxillary and mandibular premolars and molars were extracted. Each mandible received cylindrical screw implants of 3.25 mm in diameter and 10 mm in length. Prior to implanting, 4 IU of recombinant human GH and 1.2 mg of lyophilized powdered melatonin was applied to one osteotomy at each side of the mandible. None was applied at the control sites. The implants were retrieved at 2, 5, and 8 weeks for light microscopic examination, energy-dispersive x-ray microanalysis, and histomorphometric measurements in ground sections.


RESULTS
At week 2, BIC was significantly higher in the melatonin-growth hormone group than in the implant control one (34.20 vs 25.05%; p = .010). The M-GH group also increased significantly the peri-implant bone area (64.72 vs 53.20%; p = .038) and interthread bone area (35.62 vs 25.08%; p = .02). At weeks 5 and 8, BIC and bone density around implants were similar to both groups. Significant differences were detected in bone neoformation at 8 weeks in ML-GH group (9.04 vs 7.53%; p = .05). Regarding the mineral composition, in ML-GH group increments in concentrations of phosphorus (10.70 vs 10.34; p = .013) were observed at 2 weeks and of magnesium (0.29 vs 0.25; p = .019) 5 weeks after implantation.


CONCLUSIONS
The present study confirms that GH and melatonin synergistically enhance new bone formation around titanium implants in early stages of healing.
Department of Veterinary Clinical Sciences, University of Santiago de Compostela, Lugo, Spain. fernandom.munoz@usc.es
Fernando
F
Muñoz
Mónica
M
López-Peña
Natalia
N
Miño
Gerardo
G
Gómez-Moreno
Javier
J
Guardia
Antonio
A
Cutando
D000287:Administration, Topical; D000539:Alveolar Process / Q000187:drug effects* / Q000473:pathology; D000818:Animals; D000975:Antioxidants / Q000008:administration & dosage / Q000627:therapeutic use*; D001641:Bicuspid / Q000601:surgery; D015519:Bone Density / Q000187:drug effects; D016723:Bone Remodeling / Q000187:drug effects; D015921:Dental Implants; D003764:Dental Materials / Q000737:chemistry; D004285:Dogs; D019382:Human Growth Hormone / Q000008:administration & dosage / Q000627:therapeutic use*; D008274:Magnesium / Q000032:analysis; D008334:Mandible / Q000187:drug effects / Q000473:pathology / Q000601:surgery; D008550:Melatonin / Q000008:administration & dosage / Q000627:therapeutic use*; D008855:Microscopy, Electron, Scanning; D008963:Molar / Q000601:surgery; D016348:Osseointegration / Q000187:drug effects*; D010012:Osteogenesis / Q000187:drug effects; D010027:Osteotomy / Q000379:methods; D010758:Phosphorus / Q000032:analysis; D011897:Random Allocation; D011994:Recombinant Proteins; D013052:Spectrometry, X-Ray Emission; D013997:Time Factors; D014025:Titanium / Q000737:chemistry; D014081:Tooth Extraction; D020390:Tooth Socket / Q000187:drug effects / Q000601:surgery; D014945:Wound Healing / Q000187:drug effects
D000975:Antioxidants; D015921:Dental Implants; D003764:Dental Materials; D011994:Recombinant Proteins; D019382:Human Growth Hormone; D010758:Phosphorus; D014025:Titanium; D008274:Magnesium; D008550:Melatonin