Should you screw retain or cement retain your dental implant crown?

Screw retain vs cement retain for a dental implant really depends on doctor preference. Experience of the dentist is far more important than which you choose IMHO.

Screw v cement dental implant research

Results of a systemic review on screw retain vs cement retain dental implants JPD 2016 Lemos

• Cement retained have less bone loss
• Cement retained have fewer prosthetic complications
• Cement retained have more favorable survival rates

Not what I would have expected.

Wonder how a screwmentable crown would do?  By that I mean one that has separate crown and abutment that has crown cemented on in the mouth but has screw access so is removed to clean cement and then replaced.

Screw vs cement retained full arch implant supported prosthesis.

Screw retained are preferable because we can more easily deal with biological and technical problems. Cement retained has more biological problems and screw retained more technical problems. Gaddale JOI 2020

When should we splint the crowns of a dental implant?

Splinting dental implant crowns is another one of those controversies that is unclear. Reasons to consider splinting are

• Tall implant crowns, which result from significant bone loss and are thus also often on short implants.  No perfect number but crown/abutment height of 15 mm is tall and anything > 10 mm consider.
• Smaller diameter implants, especially those replacing molars. 4.0 mm diameter and under is narrow and can lead to more prosthetic complications.
• Bruxers and anyone with occlusion that results in lateral forces (although should just eliminate those)
• Although not common any more, any external hex implant
• Parafunction with lack of anterior guidance (disclusion)
• Commercially pure titanium implants

This information is mostly from To splint or not to splint in Dentistry Today Jan/Feb 2023 and is in this DT thread. Li JPros 2022 finds short implants of 8.5mm or less do the same whether splint or not.

Splinted vs non-splinted dental implants research

Research on the topic is confusing and unclear. For instance a meta-analysis by de Souza Batista Pro Dent 2019 finds no difference in marginal bone loss or prosthetic complications BUT finds splinted restorations have fewer implant failures. Seems strange that failures and bone loss do not correlate.

Should we place 3 individual dental implants in a row or place two dental implants and make a bridge?

This seems obvious to me and research from a Ravida COIR 2019 article does find the implant bridge is better. They also compare when splint 3 dental implants and when leave them as individual. However, another study that factors in lateral forces, such as those we see in group function, shows 3 individual implants help dissipate those forces. That may be a small consideration. Nagao 2019 JOI