This systematic review aims to identify and discuss the most used methodologies in pre-clinical studies for the evaluation of the implementation of dental implants in systemically compromised pigs and sheep. This study provides support and guidance for future research, as well as for the prevention of unnecessary animal wastage and sacrifice. Preferred Reporting for Systematic Reviews and Meta-Analyses (PRISMA) was used as a guideline; electronic searches were performed in PubMed, Scopus, Scielo, Web of Science, Embase, Science Direct, Brazilian Bibliography of Dentistry, Latin American and Caribbean Literature in Health Sciences, Directory of Open Access Journals, Database of Abstracts of Reviews of Effects, and gray literature until January 2022 (PROSPERO/CRD42021270119). Sixty-eight articles were chosen from the 2439 results. Most studies were conducted in pigs, mainly the Göttinger and Domesticus breeds. Healthy animals with implants installed in the jaws were predominant among the pig studies. Of the studies evaluating the effect of systemic diseases on osseointegration, 42% were performed in osteoporotic sheep, 32% in diabetic sheep, and 26% in diabetic pigs. Osteoporosis was primarily induced by bilateral ovariectomy and mainly assessed by X-ray densitometry. Diabetes was induced predominantly by intravenous streptozotocin and was confirmed by blood glucose analysis. Histological and histomorphometric analyses were the most frequently employed in the evaluation of osseointegration. The animal models presented unique methodologies for each species in the studies that evaluated dental implants in the context of systemic diseases. Understanding the most commonly used techniques will help methodological choices and the performance of future studies in implantology.
DardM. Animal models for experimental surgical research in implant dentistry. In: Ballo A (ed) Implant dentistry research guide: basic, translational and experimental clinical research. 1st ed. Huappauge, USA: Nova Biomedical, 2012, pp.167–190.
2.
KantarciAHasturkHVan DykeTE.Animal models for periodontal regeneration and peri-implant responses. Periodontol 20002015;
68: 66–82.
3.
AerssensJBoonenSLowetG, et al.
Interspecies differences in bone composition, density, and quality: potential implications for in vivo bone research. Endocrinology1998;
139: 663–670.
4.
KimSWKimKSSolisCD, et al.
Development of osteoporosis animal model using micropigs. Lab Anim Res2013;
29: 174–177.
5.
WangSLiuYFangD, et al.
The miniature pig: a useful large animal model for dental and orofacial research. Oral Dis2007;
13: 530–537.
6.
GiavaresiGFiniMCigadaA, et al.
Mechanical and histomorphometric evaluations of titanium implants with different surface treatments inserted in sheep cortical bone. Biomaterials2003;
24: 1583–1594.
7.
FiniMGiavaresiGRimondiniL, et al.
Titanium alloy osseointegration in cancellous and cortical bone of ovariectomized animals: histomorphometric and bone hardness measurements. Int J Oral Maxillofac Implants2002;
17: 28–37.
8.
BonucciEBallantiP.Osteoporosis – bone remodeling and animal models. Toxicol Pathol2014;
42: 957–969.
9.
GehrkeSATumedeiMAramburu JuniorJ, et al.
Histological and histomorphometrical evaluation of a new implant macrogeometry. A sheep study. Int J Environ Res Public Health2020;
17: 3477.
10.
SwindleMMMakinAHerronAJ, et al.
Swine as models in biomedical research and toxicology testing. Vet Pathol2012;
49: 344–356.
11.
RothJATuggleCK.Livestock models in translational medicine. ILAR J2015;
56: 1–6.
12.
KirkRGW.Recovering the principles of humane experimental technique: the 3Rs and the human essence of animal research. Sci Technol Human Values2018;
43: 622–648.
13.
NewmanETurnerASWarkJD.The potential of sheep for the study of osteopenia: current status and comparison with other animal models. Bone1995;
16: 277S–284S.
14.
WangLHuXMaX, et al.
Promotion of osteointegration under diabetic conditions by tantalum coating-based surface modification on 3-dimensional printed porous titanium implants. Colloids Surf B Biointerfaces2016;
1: 440–452.
15.
WangCJMcCauleyLK.Osteoporosis and periodontitis. Curr Osteoporos Rep2016;
14: 284–291.
16.
BorsariVFiniMGiavaresiG, et al.
Sandblasted titanium osteointegration in young, aged and ovariectomized sheep. Int J Artif Organs2007;
30: 163–172.
17.
TurnerAS.Animal models of osteoporosis – necessity and limitations. Eur Cell Mater2001;
1: 66–81.
18.
SchlegelKAPrechtlCMostT, et al.
Osseointegration of SLActive implants in diabetic pigs. Clin Oral Implants Res2013;
24: 128–134.
19.
von WilmowskyCStockmannPHarschI, et al.
Diabetes mellitus negatively affects peri-implant bone formation in the diabetic domestic pig. J Clin Periodontol2011;
38: 771–779.
20.
LiXMaXYFengYF, et al.
Osseointegration of chitosan coated porous titanium alloy implant by reactive oxygen species-mediated activation of the PI3K/AKT pathway under diabetic conditions. Biomaterials2015;
36: 44–54.
21.
LiuFLiYLiangJ, et al.
Effects of micro/nano strontium-loaded surface implants on osseointegration in ovariectomized sheep. Clin Implant Dent Relat Res2019;
21: 377–385.
22.
DavisonMRLyardetLPreliascoM, et al.
Aminobisphosphonate-treated ewes as a model of osteonecrosis of the jaw and of dental implant failure. J Periodontol2020;
91: 628–637.
23.
XiaoJRLiDHChenYX, et al.
Evaluation of fixation of expandable implants in the mandibles of ovariectomized sheep. J Oral Maxillofac Surg2013;
71: 682–688.
24.
XiaoJZhouHZhaoL, et al.
The effect of hierarchical micro/nanosurface titanium implant on osseointegration in ovariectomized sheep. Osteoporos Int2011;
22: 1907–1913.
25.
GiavaresiGChiesaRFiniM, et al.
Effect of a multiphasic anodic spark deposition coating on the improvement of implant osseointegration in the osteopenic trabecular bone of sheepInt J Oral Maxillofac Implants2008;
23: 659–668.
26.
SachseAWagnerAKellerM, et al.
Osteointegration of hydroxyapatite-titanium implants coated with nonglycosylated recombinant human bone morphogenetic protein-2 (BMP-2) in aged sheep. Bone2005;
37: 699–710.
27.
MaXYFengYFWangTS, et al.
Involvement of FAK-mediated BMP-2/Smad pathway in mediating osteoblast adhesion and differentiation on nano-HA/chitosan composite coated titanium implant under diabetic conditions. Biomater Sci2017;
6: 225–238.
28.
HuXFFengYFXiangG, et al.
Lactic acid of PLGA coating promotes angiogenesis on the interface between porous titanium and diabetic bone. J Mater Chem B2018;
6: 2274–2288.
29.
MaXYFengYFMaZS, et al.
The promotion of osteointegration under diabetic conditions using chitosan/hydroxyapatite composite coating on porous titanium surfacesBiomaterials2014;
35: 7259–7270.
30.
MaXYMaTCFengYF, et al.
Promotion of osteointegration under diabetic conditions by a silk fibroin coating on 3D-printed porous titanium implants via a ROS-mediated NF-κB pathway. Biomed Mater2021;
16.
31.
CoelhoPGPippengerBTovarN, et al.
Effect of obesity or metabolic syndrome and diabetes on osseointegration of dental implants in a miniature swine model: a pilot study. J Oral Maxillofac Surg2018;
76: 1677–1687.
32.
TanNLiuXCaiY, et al.
The influence of direct laser metal sintering implants on the early stages of osseointegration in diabetic mini-pigs. Int J Nanomedicine2017;
12: 5433–5442.
33.
von WilmowskyCSchlegelKABaranC, et al.
Peri-implant defect regeneration in the diabetic pig: a preclinical study. J Craniomaxillofac Surg2016;
44: 827–834.
34.
ZechnerWTanglSTepperG, et al.
Influence of platelet-rich plasma on osseous healing of dental implants: a histologic and histomorphometric study in minipigs. Int J Oral Maxillofac Implants2003;
18: 15–22.
35.
SchliephakeHHeftiTSchlottigF, et al.
Mechanical anchorage and peri-implant bone formation of surface-modified zirconia in minipigs. J Clin Periodontol2010;
37: 818–828.
36.
DurualSRiederPGaravagliaG, et al.
TiNOx coatings on roughened titanium and CoCr alloy accelerate early osseointegration of dental implants in minipigs. Bone2013;
52: 230–237.
37.
Percie du SertNHurstVAhluwaliaA, et al.
The ARRIVE guidelines 2.0: Updated guidelines for reporting animal research. BMC Vet Res2020;
16: 242.
38.
KöhnF.History and development of miniature, micro- and minipigs. In: McAnultyPADayanADGanderupNC, et al. (eds) The minipig in biomedical research.
Boca Raton, USA:
CRC Press Taylor & Francis Group, 2012, pp.3–16.
39.
Abdel-HaqJKarabudaCZArısanV, et al.
Osseointegration and stability of a modified sand-blasted acid-etched implant: an experimental pilot study in sheep. Clin Oral Implants Res2011;
22: 265–274.
40.
SartorettoSCAlvesAZarranzL, et al.
Hydrophilic surface of Ti6Al4V-ELI alloy improves the early bone apposition of sheep tibia. Clin Oral Implants Res2017;
28: 893–901.
41.
SiddiqiADuncanWSilvaRD, et al. Histomorphometric analysis of zirconia implants in the jaw of sheep. In: Abstract from 2015 IADR/AADR/CADR General Session Boston, United States, 2015.
42.
HaleTMBoretskyBBScheidtMJ, et al.
Evaluation of titanium dental implant osseointegration in posterior edentulous areas of micro swine. J Oral Implantol1991;
17: 118–124.
43.
MehlCKernMNeumannF, et al.
Effect of ultraviolet photofunctionalization of dental titanium implants on osseointegration. J Zhejiang Univ Sci B2018;
19: 525–534.
44.
StembirekJKyllarMPutnovaI, et al.
The pig as an experimental model for clinical craniofacial research. Lab Anim2012;
46: 269–279.
45.
SchulzMCKowaldJEstenfelderS, et al.
Site-specific variations in bone mineral density under systemic conditions inducing osteoporosis in minipigs. Front Physiol2017;
8: 426.
46.
ReinwaldSBurrD.Review of nonprimate, large animal models for osteoporosis research. J Bone Miner Res2008;
23: 1353–1368.
47.
WuZXLeiWHuYY, et al.
Effect of ovariectomy on BMD, micro-architecture and biomechanics of cortical and cancellous bones in a sheep model. Med Eng Phys2008;
30: 1112–1118.
48.
LenzenS.The mechanisms of alloxan- and streptozotocin-induced diabetes. Diabetologia2008;
51: 216–226.
49.
MarcoFMilenaFGianlucaG, et al.
Peri-implant osteogenesis in health and osteoporosis. Micron2005;
36: 630–644.
50.
Mellado-ValeroAFerrer GarcíaJCHerrera BallesterA, et al.
Effects of diabetes on the osseointegration of dental implants. Med Oral Patol Oral Cir Bucal2007;
12: E38–43.
51.
RodellaLFFaveroGSalaL, et al.
A comparative pilot study of two dental implant metals in a pig model. Implant Dent2010;
19: 532–538.
52.
von WilmowskyCMoestTNkenkeE, et al.
Implants in bone: part II. Research on implant osseointegration: material testing, mechanical testing, imaging and histoanalytical methods. Oral Maxillofac Surg2014;
18: 355–372.
53.
SerraGMoraisLSEliasCN, et al.
Sequential bone healing of immediately loaded mini-implants: histomorphometric and fluorescence analysis. Am J Orthod Dentofacial Orthop2010;
137: 80–90.
54.
GaalenSKruytMGeuzeR, et al.
Use of fluorochrome labels in in vivo bone tissue engineering research. Tissue Eng Part B Rev2009;
16: 209–217.
55.
ChappardDAguadoEHuréG, et al.
The early remodeling phases around titanium implants: a histomorphometric assessment of bone quality in a 3- and 6-month study in sheep. Int J Oral Maxillofac Implants1999;
14: 189–196.
56.
NkenkeELehnerBWeinzierlK, et al.
Bone contact, growth, and density around immediately loaded implants in the mandible of mini pigs. Clin Oral Implants Res2003;
14: 312–321.
57.
DepprichRZipprichHOmmerbornM, et al.
Osseointegration of zirconia implants: an SEM observation of the bone-implant interface. Head Face Med2008;
4: 25.
58.
von WilmowskyCBauerSLutzR, et al.
In vivo evaluation of anodic TiO2 nanotubes: an experimental study in the pig. J Biomed Mater Res B Appl Biomater2009;
89: 165–171.
59.
SchwarzFIglhautGBeckerJ.Quality assessment of reporting of animal studies on pathogenesis and treatment of peri-implant mucositis and peri-implantitis. A systematic review using the ARRIVE guidelines. J Clin Periodontol2012;
39Suppl 12: 63–72.
60.
BakerDLidsterKSottomayorA, et al.
Two years later: journals are not yet enforcing the ARRIVE guidelines on reporting standards for pre-clinical animal studies. PLoS Biol2014;
12: e1001756.
61.
Alemán-LaporteJAlvaradoGGarcia-GomesMSA, et al.
Quality of adherence to the ARRIVE guidelines in the material and methods section in studies where swine were used as surgical biomodels: a systematic review (2013–2018). Animals (Basel)2019;
9: 947.
62.
BacchelliBGiavaresiGFranchiM, et al.
Influence of a zirconia sandblasting treated surface on peri-implant bone healing: an experimental study in sheep. Acta Biomater2009;
5: 2246–2257.
63.
BerardiDDe BenedittisSScocciaA, et al.
Evaluation of neridronate on the osseointegration process of endeous titanium implants in animal models. Eur J Inflamm2011;
9: 141–149.
64.
BissingerOProbstFAWolffKD, et al.
Comparative 3D micro-CT and 2D histomorphometry analysis of dental implant osseointegration in the maxilla of minipigs. J Clin Periodontol2017;
44: 418–427.
65.
BrockmeyerPKrohnSThiemannC, et al.
Primary stability and osseointegration of dental implants in polylactide modified bone – a pilot study in Goettingen minipigs. J Craniomaxillofac Surg2016;
44: 1095–1103.
66.
BuserDSchenkRKSteinemannS, et al.
Influence of surface characteristics on bone integration of titanium implants. A histomorphometric study in miniature pigs. J Biomed Mater Res1991;
25: 889–902.
67.
BuserDNydeggerTHirtHP, et al.
Removal torque values of titanium implants in the maxilla of miniature pigs. Int J Oral Maxillofac Implants1998;
13: 611–619.
68.
ChiangHJHsuHJPengPW, et al.
Early bone response to machined, sandblasting acid etching (SLA) and novel surface-functionalization (SLAffinity) titanium implants: characterization, biomechanical analysis and histological evaluation in pigs. J Biomed Mater Res A2016;
104: 397–405.
69.
ChiesaRGiavaresiGFiniM, et al.
In vitro and in vivo performance of a novel surface treatment to enhance osseointegration of endosseous implants. Oral Surg Oral Med Oral Pathol Oral Radiol Endod2007;
103: 745–756.
70.
ElianNBloomMDardM, et al.
Effect of interimplant distance (2 and 3 mm) on the height of interimplant bone crest: a histomorphometric evaluation. J Periodontol2011;
82: 1749–1756.
71.
FranchiMBacchelliBGiavaresiG, et al.
Influence of different implant surfaces on peri-implant osteogenesis: histomorphometric analysis in sheep. J Periodontol2007;
78: 879–888.
72.
GahlertMGudehusTEichhornS, et al.
Biomechanical and histomorphometric comparison between zirconia implants with varying surface textures and a titanium implant in the maxilla of miniature pigs. Clin Oral Implants Res2007;
18: 662–668.
73.
GermanierYTosattiSBrogginiN, et al.
Enhanced bone apposition around biofunctionalized sandblasted and acid-etched titanium implant surfaces. A histomorphometric study in miniature pigs. Clin Oral Implants Res2006;
17: 251–257.
74.
GottlowJDardMKjellsonF, et al.
Evaluation of a new titanium-zirconium dental implant: a biomechanical and histological comparative study in the mini pig. Clin Implant Dent Relat Res2012;
14: 538–545.
75.
GramanziniMGargiuloSZaroneF, et al.
Combined microcomputed tomography, biomechanical and histomorphometric analysis of the peri-implant bone: a pilot study in minipig model. Dent Mater2016;
32: 794–806.
76.
GrizonFAguadoEHuréG, et al.
Enhanced bone integration of implants with increased surface roughness: a long term study in the sheep. J Dent2002;
30: 195–203.
77.
HuangH-HLiuC-FWangS, et al.
Nitrogen plasma immersion ion implantation treatment of Ti6Al7Nb alloy for bone-implant applications: Enhanced in vitro biological responses and in vivo initial bone-implant contact. Surf Coat Technol2021;
405: 126551.
78.
HuréGDonathKLesourdM, et al.
Does titanium surface treatment influence the bone-implant interface? SEM and histomorphometry in a 6-month sheep study. Int J Oral Maxillofac Implants1996;
11: 506–511.
79.
KarlMPalarieVNacuV, et al.
Effect of intraoperative bone quality testing on bone healing and osseointegration of dental implants. Int J Oral Maxillofac Implants2013;
28: 1254–1260.
80.
Lopez-SastreSGonzalo-OrdenJMAltónagaJA, et al.
Coating titanium implants with bioglass and with hydroxyapatite. A comparative study in sheep. Int Orthop1998;
22: 380–383.
81.
LutzRSrourSNonhoffJ, et al.
Biofunctionalization of titanium implants with a biomimetic active peptide (P-15) promotes early osseointegration. Clin Oral Implants Res2010;
21: 726–734.
82.
LutzRPrechtlCNonhoffJ, et al.
Biofunctionalization of the implant surface with different concentrations of a synthetic peptide (P-15). Clin Oral Implants Res2013;
24: 781–786.
83.
Mello-MachadoRCSartorettoSCGranjeiroJM, et al.
Osseodensification enables bone healing chambers with improved low-density bone site primary stability: an in vivo study. Sci Rep2021;
11: 15436.
84.
MeyerUWiesmannHPFilliesT, et al.
Early tissue reaction at the interface of immediately loaded dental implants. Int J Oral Maxillofac Implants2003;
18: 489–499.
85.
MutluİOKarabudaZCArısanV, et al.
Sustained release of vitamin D3 enhanced osseointegration capacity: an experimental sheep study. Biointerface Res Appl Chem2022;
12: 8205–8218.
86.
NkenkeELehnerBFennerM, et al.
Immediate versus delayed loading of dental implants in the maxillae of minipigs: follow-up of implant stability and implant failures. Int J Oral Maxillofac Implants2005;
20: 39–47.
87.
NonhoffJMoestTSchmittCM, et al.
Establishment of a new pull-out strength testing method to quantify early osseointegration – An experimental pilot study. J Craniomaxillofac Surg2015;
43: 1966–1973.
88.
OgunsaluCEzeokoliCArchibaldA, et al.
Comparative study of osteoblastic activity of same implants (Endopore) in the immediate extraction site utilizing single photon emission computerized tomography: peri-implant autogeneous bone grafting with GTR versus no peri-implant bone grafting – experimental study in pig model. West Indian Med J2011;
60: 336–339.
89.
RamazanogluMLutzRErgunC, et al.
The effect of combined delivery of recombinant human bone morphogenetic protein-2 and recombinant human vascular endothelial growth factor 165 from biomimetic calcium-phosphate-coated implants on osseointegration. Clin Oral Implants Res2011;
22: 1433–1439.
90.
SchlegelKAKlossFRKesslerP, et al.
Bone conditioning to enhance implant osseointegration: an experimental study in pigs. Int J Oral Maxillofac Implants2003;
18: 505–511.
91.
StadlingerBLodeATEckeltU, et al.
Surface-conditioned dental implants: an animal study on bone formation. J Clin Periodontol2009;
36: 882–891.
92.
StoccheroMToiaMJinnoY, et al.
Influence of different drilling preparation on cortical bone: a biomechanical, histological, and micro-CT study on sheep. Clin Oral Implants Res2018;
29: 707–715.
93.
StrickerAFleinerJDardM, et al.
Evaluation of a new experimental model to study bone healing after ridge expansion with simultaneous implant placement – a pilot study in minipigs. Clin Oral Implants Res2014;
25: 1265–1272.
94.
VasakCBusenlechnerDSchwarzeUY, et al.
Early bone apposition to hydrophilic and hydrophobic titanium implant surfaces: a histologic and histomorphometric study in minipigs. Clin Oral Implants Res2014;
25: 1378–1385.
95.
VlaminckLGorskiTHuysL, et al.
Immediate postextraction implant placement in sheep's mandibles: a pilot study. Implant Dent2008;
17: 439–450.
96.
WitekLParraMTovarN, et al.
Effect of surgical Instrumentation variables on the osseointegration of narrow- and wide-diameter short implants. J Oral Maxillofac Surg2021;
79: 346–355.
97.
ZechnerWTanglSFürstG, et al.
Osseous healing characteristics of three different implant types. Clin Oral Implants Res2003;
14: 150–157.
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