Evaluation of Accuracy of Casts of Multiple Internal Connection Implant Prosthesis Obtained From Different Impression Materials and Techniques: An In Vitro Study

Abstract

Movement of impression copings inside the impression material using a direct (open tray) impression technique during clinical and laboratory phases may cause inaccuracy in transferring the 3-dimensional spatial orientation of implants intraorally to the cast. Consequently, the prosthesis may require corrective procedures. This in vitro study evaluated the accuracy of 3 different impression techniques using polyether and vinyl polysiloxane (VPS) impression material to obtain a precise cast for multiple internal connection implants. A reference acrylic resin model with 4 internal connection implants was fabricated. Impressions of the reference model were made using 3 different techniques and 2 different impression materials. The study consisted of 24 specimens divided into 6 groups of 4 each. Impressions were poured with ADA type IV stone (Kalrock, Kalabhai Karson Pvt Ltd, Mumbai, India). All casts were evaluated for the positional accuracy (mm) of the implant replica heads using a profile projector. These measurements were compared to the measurements calculated on the reference resin model, which served as a control. Data were analyzed with 2-way analysis of variance (ANOVA) followed by Bonferroni multiple comparison procedures to evaluate group means. The results revealed significant difference for anterior implant distance between the 2 impression materials (P < .01) and also among the 3 different techniques (P < .05). The lowest mean variation was found with the polyether impression material and the splinted technique. For posterior implants, the results suggested no significant difference between the 2 impression materials (P ≥ .05). Although results were not statistically significant, the polyether impression material showed the lowest mean variation as compared to the VPS impression material. However, there was a significant difference among the 3 different techniques (P < .05). Among the 3 different techniques, the lowest mean variation between 2 posterior implants was found in the splinted technique. Casts obtained from impression techniques using square impression copings splinted together with autopolymerizing acrylic resin prior to the impression procedure were more accurate than casts obtained from impressions with nonmodified implant impression copings and with airborne particle-abraded, adhesive-coated copings. Casts obtained from polyether impression material were more accurate than casts obtained from vinyl polysiloxane impression material.

The accuracy of different dental impression techniques for implant‐supported dental prostheses: A systematic review and meta‐analysis

“…Conventional implant impressions were performed with the open tray method (Akalin et al., ; Aldosari, ; Aldosari et al., ; Amin et al., ; de Avila, de Matos Moraes, Castanharo, Del'Acqua, & de Assis Mollo, ; Bergin et al., ; Beyabanaki, Shamshiri, Alikhasi, & Monzavi, ; Buzayan, Baig, & Yunus, ; Di Fiore et al., ; Ehsani et al., ; Geramipanah, Sahebi, Davari, Hajimahmoudi, & Rakhshan, ; Ghahremanloo et al., ; Ghanem, Nassani, Baroudi, & Abdel Fattah, ; Gupta et al., ; Heidari et al., ; Lin et al., ; Marotti et al., ; Ongül et al., ; Ono et al., ; Papaspyridakos et al., ; Perez‐Davidi et al., ; Pozzi et al., ; Pujari, Garg, & Prithviraj, ; Selvaraj, Dorairaj, Mohan & Simon, ; Vigolo, Mutinelli, Fonzi & Stellini, ; Vojdani, Torabi, & Ansarifard, ; Zen et al., ), the closed tray method (Abdel‐Azim et al., ; Calesini et al., ; Del'acqua, de Avila, Amaral, Pinelli, & de Assis Mollo, ; Gökçen‐Rohlig et al., ; Ibrahim, Fouad, Elewa, & Mustafa, ; Ibrahim & Ghuneim, ; Karl et al., ; Lee et al., ; Reddy, Prasad, Vakil, Jain, & Chowdhary, ) or both the open and closed tray methods for comparison of the accuracy (Al Quran et al., ; Alikhasi, Siadat, Beyabanaki, & Kharazifard, ; Alikhasi, Siadat, & Rahimian, ; de Avila, Barros, Del'Acqua, Castanharo, & Mollo Fde, ; BalaMurugan & Manimaran, ; Chang, Vahidi, Bae, & Lim, ; Haghi, Shiehzadeh, Nakhaei, Ahrary, & Sabzevari, ; Hazboun, ; Howell et al., ; Karl & Palarie, ; Mpikos et al., ; Nakhaei, Madani, Moraditalab, & Haghi, ; Ng et al., ; Pera et al., ; Rutkunas, Sveikata, & Savickas, ; Sabouhi et al., , ; ...…”

“…Thirty‐two studies used nonsplinted impression copings (Akalin et al., ; Aldosari, ; Aldosari et al., ; Alikhasi et al., ; Alikhasi, Siadat, Beyabanaki et al., ; Alikhasi, Siadat, & Rahimian, ; BalaMurugan & Manimaran, ; Calesini et al., ; Ebadian et al., ; Ehsani et al., ; Eliasson & Ortorp, ; Geramipanah et al., ; Ghahremanloo et al., ; Gökçen‐Rohlig et al., ; Haghi et al., ; Howell et al., ; Ibrahim et al., ; Karl & Palarie, ; Karl et al., ; Lee et al., ; Lin et al., ; Marotti et al., ; Mpikos et al., ; Nakhaei et al., ; Ng et al., ; Rashidan et al., ; Reddy et al., ; Sabouhi et al., ; Shim et al., ; Siadat et al., ; Vojdani et al., ; Wegner et al., ), whereas seven studies used splinted impression copings for open tray impressions (Amin et al., ; Bergin et al., ; Di Fiore et al., ; Gupta et al., ; Ono et al., ; Rutkunas et al., ; Selvaraj et al., ) and one study splinted conical transfer copings for closed tray impressions. Twenty‐five studies compared splinted and nonsplinted impression techniques (Al‐Abdullah et al., ; de Avila et al., , ; Beyabanaki et al., ; Buzayan et al., ; Chang et al., ; Del'acqua et al., ; Ghanem et al., ; Hazboun, ; Heidari et al., ; Ibrahim & Ghuneim, ; Kurtulmus‐Yilmaz et al., ; Martínez‐Rus et al., ; Ongül et al., ; Papaspyridakos et al., ; Pera et al., ; Perez‐Davidi et al., ; Pujari et al., ; Sabouhi et al., ; Shankar et al.,…”

Accuracy of 3 different impression techniques for internal connection angulated implants

“…4,7,12,15,17,20,21 This was done without considering the possible inaccuracies arising from the setting expansion of the dental stone, which may have a negative influence on positioning the laboratory analogs. In this investigation, the accuracy of 3 different impression techniques was evaluated by directly measuring the positional deviations between the implant body/impression coping before the impression procedure and the coping/laboratory analog after the impression procedure to avoid the undesirable dimensional changes and possible inaccuracies of the dental stone.…”

“…These findings are in agreement with several studies which reported the superiority of the splinted technique for internal connection implants. [11][12][13][14][15][16][17] Moreover, regarding implant angulation, 3 in vitro investigations showed that the splinted technique was more accurate than the nonsplinted technique for making an impression of angulated implants. 5,7,16 Some authors, however, have found no significant differences in the accuracy of internal connection implant impressions with the splinted and nonsplinted techniques.…”

“…8,10 Moreover, most clinicians have suggested that the direct technique with splinting of impression copings in internal connection implants provides greater accuracy than that of the nonsplinted technique. [12][13][14][15][16][17] In contrast to those findings, other studies have reported no significant differences in internal connection implant impression accuracy resulting from splinted versus nonsplinted techniques. [18][19][20][21] Although different materials have been proposed for impression coping splinting, including impression plaster, polyether, and light-polymerizing composite resin, autopolymerizing acrylic resin splinting with or without dental floss is used more often to prevent coping movements during the impression-making procedure.…”