Summary of findings for the main comparison. Ball compared to bar attachment systems for implant overdentures in edentulous jaws.
| Interventions for replacing missing teeth: attachment systems for implant overdentures in edentulous jaws | ||||||
| Patient or population: edentulous adults receiving implant overdentures in one or both jaws to overcome problems with conventional complete dentures Setting: dental clinics (university clinics and/or private practice clinics) Intervention: ball attachment system of mandibular overdentures Comparison: bar attachment system of mandibular overdentures | ||||||
| Outcomes | Anticipated absolute effects* (95% CI) | Relative effect (95% CI) | Number of participants (studies) | Certainty of the evidence (GRADE) | Comments | |
| Risk with bar attachment system | Risk with ball attachment system | |||||
| Success (short term) Follow‐up: range 1 year to 3 years | Study population | ‐ | 130 (2 RCTs) | ⊕⊝⊝⊝ VERY LOW1 | Considerable heterogeneity (I2 = 97%). Pooling of data was not done | |
| See comment | See comment | |||||
| Re‐treatment (repair) (short term) Follow‐up: range 1 year to 3 years | Study population | RR 3.11 (1.68 to 5.75) | 130 (2 RCTs) | ⊕⊝⊝⊝ VERY LOW1 | ||
| 141 per 1000 | 437 per 1000 (236 to 809) | |||||
| Re‐treatment (replace) (short term) Follow‐up: range 1 year to 3 years | Study population | RR 1.18 (0.38 to 3.71) | 130 (2 RCTs) | ⊕⊝⊝⊝ VERY LOW1 | ||
| 78 per 1000 | 92 per 1000 (30 to 290) | |||||
| *The risk in the intervention group (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI). CI: confidence interval; RCT: randomised controlled trial; RR: risk ratio. | ||||||
| GRADE Working Group grades of evidence High certainty: we are very confident that the true effect lies close to that of the estimate of the effect. Moderate certainty: we are moderately confident in the effect estimate: the true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different. Low certainty: our confidence in the effect estimate is limited: the true effect may be substantially different from the estimate of the effect. Very low certainty: we have very little confidence in the effect estimate: the true effect is likely to be substantially different from the estimate of effect. | ||||||
1Risk of bias (serious), inconsistency (very serious), imprecision (very serious); downgraded by 3 levels.