What do systematic reviews say?

Metal-free implant abutments (zirconia) vs Metal implant abutments (titanium)

• Metal‐free materials for fixed prosthodontic restorations 2017 · Cochrane All outcomes

  12 months
  At 12 months no complications were reported in either group.
  2 studies · 47 participants
  Very low

Metal-free implant-supported FDPs (zirconia-toughened alumina; In-Ceram Zirconia) vs Metal-free implant-supported FDPs (yttria-stabilized tetragonal zirconia; Denzir)

It is very uncertain whether metal-free implant-supported FDPs (zirconia-toughened alumina;… changes bridge complications compared with metal-free implant-supported FDPs (yttria-stabilized tetragonal… (very low certainty).

• Metal‐free materials for fixed prosthodontic restorations 2017 · Cochrane All outcomes

  60 months
  OR 0.02 [0.00, 0.42]
  1 study · 18 participants
  Very low
• Metal‐free materials for fixed prosthodontic restorations 2017 · Cochrane All outcomes

  36 months
  OR 0.02 [0.00, 0.30]
  1 study · 18 participants
  Very low
• Metal‐free materials for fixed prosthodontic restorations 2017 · Cochrane All outcomes

  12 months
  OR 0.04 [0.00, 0.48]
  1 study · 18 participants
  Very low

Metal-free FDPs (lithium disilicate) vs Metal-ceramic FDPs

It is very uncertain whether metal-free FDPs (lithium disilicate) changes bridge complications compared with metal-ceramic FDPs (very low certainty).

• Metal‐free materials for fixed prosthodontic restorations 2017 · Cochrane All outcomes

  72 months
  OR 0.07 [0.01, 0.75]
  1 study · 22 participants
  Very low

Metal-free FDPs (zirconia ceramic) vs Metal-ceramic FDPs

It is very uncertain whether metal-free FDPs (zirconia ceramic) changes bridge complications compared with metal-ceramic FDPs (very low certainty).

• Metal‐free materials for fixed prosthodontic restorations 2017 · Cochrane All outcomes

  36 months
  OR 1.94 [0.38, 9.88]
  1 study · 34 participants
  Very low

Metal-free tooth-supported FDPs (pressed veneering ceramic) vs Metal-free tooth-supported FDPs (layered veneering ceramic)

It is very uncertain whether metal-free tooth-supported FDPs (pressed veneering ceramic) changes bridge complications compared with metal-free tooth-supported FDPs (layered veneering ceramic) (very low certainty).

• Metal‐free materials for fixed prosthodontic restorations 2017 · Cochrane All outcomes

  36 months
  OR 2.80 [0.66, 11.92]
  1 study · 36 participants
  Very low

Metal-free cantilevered FDPs (feldspathic-veneered zirconia) vs Metal-ceramic cantilevered FDPs

It is very uncertain whether metal-free cantilevered FDPs (feldspathic-veneered zirconia) changes cantilevered bridge complications compared with metal-ceramic cantilevered FDPs (very low certainty).

• Metal‐free materials for fixed prosthodontic restorations 2017 · Cochrane All outcomes

  24 months
  OR 5.59 [0.23, 133.61]
  1 study · 19 participants
  Very low
• Metal‐free materials for fixed prosthodontic restorations 2017 · Cochrane All outcomes

  36 months
  OR 2.00 [0.15, 26.73]
  1 study · 19 participants
  Very low

DHAT-delivered dental care vs Dentist-delivered dental care

No significant difference was reported between DHATs and dentists in diagnosis consistency or postoperative complications, without a GRADE rating.

• Reducing Alaska Native paediatric oral health disparities: a systematic review of oral health interventions and a case… 2013 All outcomes

  Alaska
  There was no significant difference between DHATs and dentists in consistency of diagnosis or postoperative complications.
  1 study
  GRADE not reported