Conical (Morse taper) connection
Also known as: Morse taper, Conical connection, Internal cone, Morse cone, Tapered connection
An internal connection in which the abutment seats into a tapered bore in the implant, so that friction between the two conical surfaces carries much of the joint’s stability rather than the screw alone.
Key facts
| Connection category | Internal connection, conical subtype. The abutment is fixed by the mechanical properties of a machine taper, locking the two components by friction between the walls rather than by screw preload alone.Verified spec[2][3] |
|---|---|
| Taper angle | Angles differ by manufacturer. A 2020 review reports internal cones of 8 or 11 degrees depending on the brand. Neodent’s literature review states that the principle, patented by Stephen A. Morse in 1864 with a 2 degree taper, was adapted for orthopaedic use in the 1970s with angles between 5 and 18 degrees, and that dental implants commonly use either 8 or 16 degrees.Verified spec[2][1]Angles are also quoted inconsistently across the industry: some manufacturers state the half-angle of one wall, others the full included angle. A "16 degree" and an "8 degree" connection may describe the same geometry measured two ways. |
| Anti-rotation feature | A pure cone has none - the abutment can be rotated to any position before it is tightened. Most commercial conical connections therefore add an index, whether grooves, an internal hexagon, an octagon or lobes, so that the abutment can be seated in a repeatable orientation. |
| Platform switching | A 2012 systematic review and meta-analysis of 10 randomised controlled trials (435 subjects, 993 implants) reported a mean 0.55 mm reduction in marginal bone loss for platform-switched implants compared with conventionally restored implants (95 per cent CI -0.86 to -0.24 mm, p = 0.0006), with no statistically significant difference in implant success. Subgroup analysis suggested less bone loss where the mismatch between implant and abutment diameter was larger.Verified spec[4]The authors themselves urged cautious interpretation because of heterogeneity between the trials and possible publication bias. |
| Clinical evidence | A 2017 systematic review found conical connections produced the smallest microgaps of the designs compared, around 2 to 3 micrometres against about 10 micrometres for external hexagons, with better sealing maintained under cyclic loading. A 2020 review concluded that the conical abutment appears to result in fewer mechanical complications such as screw loosening or fracture, higher torque preservation, and more homogeneous load distribution along the fixture and surrounding bone.Verified spec[3][2] |
Overview
A Morse taper is not a dental invention at all: it is a nineteenth-century machine-shop method for joining two parts by pressing matching cones together until friction holds them, and it reached implants by way of orthopaedics. In an implant, the practical consequence is that the screw is no longer the only thing resisting the joint coming apart, which is why the comparative literature consistently finds less screw loosening and a much tighter seal against bacterial movement than flat-seated designs achieve. Two cautions belong with that. First, the angle figures quoted in marketing are not comparable across manufacturers, because some quote the half-angle of a single wall and others the full included angle - the same cone can be described as 8 degrees or 16. Second, conical connections are usually sold together with platform switching, and the two are separate design decisions with separate evidence. The meta-analytic estimate for platform switching alone is around half a millimetre less marginal bone loss, which is meaningful but modest, and does not transfer automatically to every conical implant on the market.
Sources
Numbers match the citations beside each claim above.
Primary sources
- [1]Clinical fundamentals and scientific evidence behind the Neodent Grand Morse implant system — a literature review — Neodent (JJGC Industria e Comercio de Materiais Dentarios S.A.), Straumann Group. Accessed 2026-07-21.
Clinical evidence
- [2]Review of the Mechanical Behavior of Different Implant-Abutment Connections — International Journal of Environmental Research and Public Health, via PubMed Central, 2020. Accessed 2026-07-21.
- [3]Microleakage at the Different Implant Abutment Interface: A Systematic Review — Journal of Clinical and Diagnostic Research, via PubMed Central, 2017. Accessed 2026-07-21.
- [4]Peri-implant marginal bone level: a systematic review and meta-analysis of studies comparing platform switching versus conventionally restored implants — Journal of Clinical Periodontology (PubMed record), 2012. Accessed 2026-07-21.