What do systematic reviews say?

Single-stage alginate impression (simplified method) vs Two stage-two step elastomer (silicone, polysulfide, or polyether) conventional method

• Final‐impression techniques and materials for making complete and removable partial dentures 2018 · Cochrane All outcomes

  6 months
  There was insufficient evidence of a clear difference between groups at six-month follow-up in operator-assessed quality of the dentures (Kawai 2005).
  1 study
  GRADE not reported

Altered-cast impression technique (ACIP), polyether vs One-piece cast technique (OPC), polyether

Altered-cast impression technique (ACIP), polyether led to lower denture base adaptation (buccal shelf and ridge crest) compared with one-piece cast technique (OPC), polyether; GRADE not reported.

• Final‐impression techniques and materials for making complete and removable partial dentures 2018 · Cochrane All outcomes

  1 year
  MD -0.11 [-0.18, -0.04]
  1 study
  GRADE not reported

Wax (fluid wax), two stage-two step selective pressure final impression vs Polysulfide rubber (elastomer)

The review found no eligible studies for this question.

• Final‐impression techniques and materials for making complete and removable partial dentures 2018 · Cochrane All outcomes
  Not measured
  0 studies
  No studies found

Wax (fluid wax), two stage-two step selective pressure final impression vs Polysulfide rubber (elastomer)

The review found no eligible studies for this question.

• Final‐impression techniques and materials for making complete and removable partial dentures 2018 · Cochrane All outcomes
  Not measured
  0 studies
  No studies found

Ball (stud) attachment system vs Bar attachment system

It is very uncertain whether ball (stud) attachment system changes re-treatment: repair of attachment system (short term) compared with bar attachment system (very low certainty).

• Interventions for replacing missing teeth: attachment systems for implant overdentures in edentulous jaws 2018 · Cochrane All outcomes

  Short term (1 to 3 years)
  RR 3.11 [1.68, 5.75]
  2 studies · 130 participants
  Very low

Ball (stud) attachment system vs Bar attachment system

• Interventions for replacing missing teeth: attachment systems for implant overdentures in edentulous jaws 2018 · Cochrane All outcomes

  Short term (1 to 3 years)
  Considerable heterogeneity (I2 = 97%). Pooling of data was not done. See comment / See comment
  2 studies · 130 participants
  Very low

Selective pressure final-impression technique (two stage-two step, silicone elastomer) vs Traditional technique (redistributing pressure) and control technique (relatively mucostatic standard procedure)

• Final‐impression techniques and materials for making complete and removable partial dentures 2018 · Cochrane All outcomes

  4 to 5 weeks
  33 participants chose dentures made using the selective pressure technique, 19 chose the traditionally-made denture and 14 chose the control denture. There was no clear preference between the traditional and control…
  1 study · 69 participants
  Low

Biofunctional Prosthetic System (BPS): closed-mouth two stage-two step final impression with addition silicone elastomer vs Conventional complete denture technique (CCD): open-mouth two stage-two step conventional technique using elastomer

• Final‐impression techniques and materials for making complete and removable partial dentures 2018 · Cochrane All outcomes

  3 months
  OHIP-EDENT median scores: BPS 34.5; CCD 35.8. No clear difference between groups
  1 study · 10 participants
  Very low

Biofunctional Prosthetic System (BPS): closed-mouth two stage-two step final impression with addition silicone elastomer vs Conventional complete denture technique (CCD): open-mouth two stage-two step conventional technique using elastomer

• Final‐impression techniques and materials for making complete and removable partial dentures 2018 · Cochrane All outcomes

  3 months
  Median number of denture adjustments: BPS 3.5; CCD 4.5. BPS required fewer adjustments
  1 study · 10 participants
  Very low

Ball (stud) attachment system vs Bar attachment system

• Interventions for replacing missing teeth: attachment systems for implant overdentures in edentulous jaws 2018 · Cochrane All outcomes
  Walton 2002 reported costs but the data could not be used due to failure to report means and standard deviations and only providing the median of the costs.
  1 study
  GRADE not reported

Altered-cast impression technique (ACIP), polyether vs One-piece cast technique (OPC), polyether

It is very uncertain whether altered-cast impression technique (ACIP), polyether changes number of intaglio adjustments compared with one-piece cast technique (OPC), polyether (very low certainty).

• Final‐impression techniques and materials for making complete and removable partial dentures 2018 · Cochrane All outcomes

  1 year
  RR 1.43 [0.61, 3.34]
  1 study · 72 participants
  Very low

Single-stage alginate impression (simplified method) vs Two stage-two step elastomer (silicone, polysulfide, or polyether) conventional method

It is very uncertain whether single-stage alginate impression (simplified method) changes participant-reported quality of the denture (general satisfaction,… compared with two stage-two step elastomer (silicone, polysulfide, or polyether)… (very low certainty).

• Final‐impression techniques and materials for making complete and removable partial dentures 2018 · Cochrane All outcomes

  6 months
  MD 0 [-8.23, 8.23]
  1 study · 105 participants
  Very low

Ball (stud) attachment system vs Bar attachment system

• Interventions for replacing missing teeth: attachment systems for implant overdentures in edentulous jaws 2018 · Cochrane All outcomes
  Only Walton 2002 assessed patient satisfaction but reported narrative results and failed to provide any usable numbers. Quality of life as assessed by a validated measure was not recorded in any of the trials.
  1 study
  GRADE not reported

Ball (stud) attachment system vs Telescopic attachment system

The review found no eligible studies for this question.

• Interventions for replacing missing teeth: attachment systems for implant overdentures in edentulous jaws 2018 · Cochrane All outcomes
  no estimate extracted
  Studies not reported
  No studies found

Alginate (two stage-two step final/wash impression) vs Silicone elastomer (two stage-two step)

• Final‐impression techniques and materials for making complete and removable partial dentures 2018 · Cochrane All outcomes

  2 weeks
  The study reported that there was no difference between groups for comfort, but that more participants reported better stability and chewing efficiency with silicone. Data were not amenable to analysis.
  1 study
  GRADE not reported

Ball (stud) attachment system vs Telescopic attachment system

It is very uncertain whether ball (stud) attachment system changes prosthodontic maintenance: patrix replaced (short term) compared with telescopic attachment system (very low certainty).

• Interventions for replacing missing teeth: attachment systems for implant overdentures in edentulous jaws 2018 · Cochrane All outcomes

  Short term (1 to 3 years)
  RR 6.00 [0.86, 41.96]
  1 study · 22 participants
  Very low

Altered-cast impression technique (ACIP), polyether vs One-piece cast technique (OPC), polyether

The review found no eligible studies for this question.

• Final‐impression techniques and materials for making complete and removable partial dentures 2018 · Cochrane All outcomes
  Not measured
  0 studies
  No studies found

Single-stage alginate impression (simplified method) vs Two stage-two step zinc-oxide eugenol (ZoE) traditional method

It is very uncertain whether single-stage alginate impression (simplified method) changes participant-reported oral health-related quality of life (OHIP-EDENT) compared with two stage-two step zinc-oxide eugenol (ZoE) traditional method (very low certainty).

• Final‐impression techniques and materials for making complete and removable partial dentures 2018 · Cochrane All outcomes

  6 months
  MD 0.5 [-2.67, 3.67]
  1 study · 39 participants
  Very low

Altered-cast impression technique (ACIP), polyether vs One-piece cast technique (OPC), polyether

It is very uncertain whether altered-cast impression technique (ACIP), polyether changes abutment mobility compared with one-piece cast technique (OPC), polyether (very low certainty).

• Final‐impression techniques and materials for making complete and removable partial dentures 2018 · Cochrane All outcomes

  1 year · left abutment
  RR 1.16 [0.40, 3.37]
  1 study
  Very low
• Final‐impression techniques and materials for making complete and removable partial dentures 2018 · Cochrane All outcomes

  1 year · right abutment
  RR 2.90 [0.87, 9.61]
  1 study
  Very low

Ball (stud) attachment system vs Telescopic attachment system

It is very uncertain whether ball (stud) attachment system changes prosthodontic maintenance: matrix activated (short term) compared with telescopic attachment system (very low certainty).

• Interventions for replacing missing teeth: attachment systems for implant overdentures in edentulous jaws 2018 · Cochrane All outcomes

  Short term (1 to 3 years)
  RR 11.00 [0.68, 177.72]
  1 study · 22 participants
  Very low