Table 6. GRADE summary of findings.
| Intervention | No. of specimens treated (studies) | Risk of bias | Inconsistency | Indirectness | Imprecision | Publication bias | Overall certainty of evidence |
|---|---|---|---|---|---|---|---|
| Non-metal hand instruments | 40 (3 studies) | Not serious | Seriousb) | Seriousc) | Indeterminable | Not suspected | ⊕⊕○○ |
| Low | |||||||
| Metal hand instruments | 104 (5 studies) | Not serious | Seriousb) | Seriousc) | Indeterminable | Not suspected | ⊕⊕○○ |
| Low | |||||||
| Rubber cups | 12 (1 study) | Not serious | No | Seriousc) | Indeterminable | Not suspected | ⊕⊕⊕○ |
| Moderate | |||||||
| Air-abrasive devices | 12 (1 study) | Not serious | No | Seriousc) | Indeterminable | Not suspected | ⊕⊕⊕○ |
| Moderate | |||||||
| Ultrasonic scalers with non-metal tips | 29 (3 studies) | Not serious | Seriousb) | Seriousc) | Indeterminable | Not suspected | ⊕⊕○○ |
| Low | |||||||
| Ultrasonic scalers with metal tips | 94 (4 studies) | Not serious | Seriousb) | Seriousc) | Indeterminable | Not suspected | ⊕⊕○○ |
| Low | |||||||
| Laser system | 155 (5 studies) | Very seriousa) | Seriousb) | Seriousc) | Indeterminable | Not suspected | ⊕○○○ |
| Very low |
Outcome of interest: surface roughness (for which a single pooled effect estimate was not available and only a narrative synthesis of the evidence was provided). GRADE Working Group grades of evidence: i) High quality: Further research is very unlikely to change our confidence in the estimate of the effect; ii) Moderate quality: Further research is likely to have an important impact on our confidence in the estimate of the effect and may change the estimate; iii) Low quality: Further research is very likely to have an important impact on our confidence in the estimate of the effect and is likely to change the estimate; iv) Very low quality: Any estimate of the effect is very uncertain
a)The evidence was downgraded by 2 levels due to very serious concern regarding the risk of bias; 1 or more included studies have high risk of bias. b)The evidence was downgraded by 1 level due to a high degree of heterogenity in study methodologies. c)The evidence was downgraded by 1 level due to the use of discs as a representative study material of dental implants.