Evaluation of removal forces of implant-supported zirconia copings depending on abutment geometry, luting agent and cleaning method during re-cementation

Abstract

PURPOSETo evaluate the effects of different abutment geometries in combination with varying luting agents and the effectiveness of different cleaning methods (prior to re-cementation) regarding the retentiveness of zirconia copings on implants.MATERIALS AND METHODSImplants were embedded in resin blocks. Three groups of titanium abutments (pre-fabricated, height: 7.5 mm, taper: 5.7°; customized-long, height: 6.79 mm, taper: 4.8°; customized-short, height: 4.31 mm, taper: 4.8°) were used for luting of CAD/CAM-fabricated zirconia copings with a semi-permanent (Telio CS) and a provisional cement (TempBond NE). Retention forces were evaluated using a universal testing machine. Furthermore, the influence of cleaning methods (manually, manually in combination with ultrasonic bath or sandblasting) prior to re-cementation with a provisional cement (TempBond NE) was investigated with the pre-fabricated titanium abutments (height: 7.5 mm, taper: 5.7°) and SEM-analysis of inner surfaces of the copings was performed. Significant differences were determined via two-way ANOVA.RESULTSSignificant interactions between abutment geometry and luting agent were observed. TempBond NE showed the highest level of retentiveness on customized-long abutments, but was negatively affected by other abutment geometries. In contrast, luting with Telio CS demonstrated consistent results irrespective of the varying abutment geometries. Manual cleaning in combination with an ultrasonic bath was the only cleaning method tested prior to re-cementation that revealed retentiveness levels not inferior to primary cementation.CONCLUSIONNo superiority for one of the two cements could be demonstrated because their influences on retentive strength are also depending on abutment geometry. Only manual cleaning in combination with an ultrasonic bath offers retentiveness levels after re-cementation comparable to those of primary luting.

Influence of abutment height and convergence angle on the retrievability of cement-retained implant prostheses with a lingual slot

“…When the convergence angle remained constant, there was a significant increase in removal torque values when the height of abutment increased. These results coincide with those of previous studies 15 16 that analyzed the differences in prosthesis retention depending on the height of the abutment and the changes in surface area. When fabricating customized abutments in clinical settings, controlling convergence angles is recommended to support prosthesis retention, as the height of the abutment is limited by the intermaxillary space.…”

“…5B ). These findings support the results of a previous study 15 that used resin cement to bond to abutments with heights of less than 2 mm.…”

Clinical evaluation of an improved cementation technique for implant‐supported restorations: a randomized controlled trial

“…; Rödiger et al. ). Following these principles, abutments used in the present study have been designed with a convergency angle of axial walls ranging from 8° to 12° and only two crowns decemented after 1 week which were recemented with no further complication.…”

Influence of Luting Materials on the Retention of Cemented Implant-Supported Crowns: An In Vitro Study

“…The biological factors are age, systemic health, medication, oral disease [ 4 ], bone support [ 6 ], occlusion [ 7 ], hard and soft peri-implant tissue quality [ 4 ], changes [ 8 ] in bacterial colonization around implants and around teeth, type of the oral hygiene [ 3 , 9 , 10 ], and smoking [ 4 ]. The technical factors include amount of retention [ 11 ], devices for implant-supported prosthesis retention [ 12 ], type of retention force applied [ 13 ], crown and implant abutment materials, geometry, height, type of the surface finishing, surface roughness [ 14 , 15 , 16 ], cleaning method during recementation [ 17 ], and the chemical, physical, bioactive and “remove-on-demand” properties of the luting material [ 11 , 12 , 16 ]. One of the actual topics of interest in the field of biology-driven implant therapy is implant restoration [ 2 , 18 , 19 ], and this topic has induced the development of new methods and luting materials for implant-supported prosthesis retention [ 11 , 20 ].…”