Occlusal vs non-occlusal modality of the loading protocol for oral implants in partially edentulous patients: a systematic review and meta-analysis.

BACKGROUND

Occlusal loading refers to a modality in which an implant-supported prosthesis is subjected to functional loading, maintaining contact with the opposing dentition from the onset of prosthetic placement. In contrast, non-occlusal loading represents a non-functional approach, wherein a provisional implant prosthesis is initially placed in infra-occlusion or fully relieved of contact with the opposing dentition, which is subsequently (at a later stage) followed by functional (occlusal) loading with the definitive prosthesis.

AIM

To compare clinical outcomes in partially edentulous cases following an occlusal modality of loading versus non-occlusal modality of loading.

METHOD

A search on Pubmed, Scopus and Embase databases was conducted to identify randomised controlled trials (RCTs) comparing occlusal versus non-occlusal modalities of implant loading in partially edentulous patients receiving implants with single crowns or fixed bridges, between January 1 (2004) to June 12 (2024), examining implant survival, complications and marginal bone loss (MBL) of implants. The inclusion criteria involved RCTs of evidence level II (Oxford Centre for Evidence-Based Medicine Levels of Evidence). For assessing bias in the included studies, the Cochrane Risk of Bias tool was used.

RESULTS

This review identified seven RCTs investigating 273 implants over 1-3 years follow-up periods. seven studies reported 1-year MBL data and three reported 3-year data. Publication bias was noted at the 1-year follow-up (p < 0.01) but not at 3 years (p > 0.05). Differences in MBL were not statistically significant at both 1 year (Hedges' d = 0.01, p = 0.920, 95% CI: [-0.21, 0.24]) and 3 years (Hedges' d = 0.01, p = 0.952, 95% CI: [-0.28, 0.30]). Differences in complication occurrences were not statistically significant (RR = 0.882, p = 0.759, 95% CI: [0.397, 1.964]). The nature of data on implant survival rates prevented a meaningful meta-analysis.

CONCLUSION

For short-term periods of 1-3 years, no significant evidence supports clinical superiority in terms of complication rates and MBL between non-occlusal and occlusal modalities of implant loading. Future studies should explore functional and aesthetic aspects, as well as patient reported outcomes to determine any short-term differences or consider long-term follow-up with large sample sizes to detect significant clinical differences.