Category: Laboratory Research
Award Category: Student Scientist
Layered Injection Molding: A Pre-clinical Evaluation of a Clinical Possibility
Bipin Raj Kruthia* (kruthibraj@gmail.com) | Manoj Sindagi Swabhaanua
aRajiv Gandhi University of Health Sciences, Bangalore, India
Objective: The objective of this preclinical study was to evaluate a predictable technique which combines layering and injection molding for easy, efficient and consistent polychromatic anterior restorations with uncompromised esthetics.
Methods: This preclinical study was conducted on Nissin 300 Series Standard Jaw Model (GNR300-U) with push-type typodont teeth. 30 Maxillary anterior typodonts (11, 12, 13, 21, 22 and 23) were prepared using diamond abrasives to simulate a clinical scenario with multiple diastemata and divided into equal groups. Group A was restored using the traditional injection molding technique and Group B was restored using the experimental technique which combines the histological layering technique with the traditional injection molding technique. Unprepared typodonts were used as a laboratory wax up for consistency and reproducibility. Stents were prepared using a clear, vinyl polysiloxane impression material (Exaclear,GC). Samples of Group A were restored with G-ænial Universal Flo (GC) after etching and adhesive protocol. For Group B, after etching and bonding protocol, packable composite (Filtek Z350, 3M; Shades A3, A2, A1, CT) was used to create internal anatomical features such as mamelons, incisal halo and cervical high value areas as per the histological layering concept following which G-ænial Universal Flo (GC) was injected to mimic the enamel layer. Standardized finishing and polishing protocols were followed for both groups. An esthetic evaluation was performed by blinded evaluators using the FDI World Dental Federation clinical criteria for direct restorations. The parameters considered were surface luster, translucency and esthetic anatomical form.
Results: Surface luster of both groups was comparable; Group B received better scores for translucency and esthetic anatomical form.
Conclusion: This preclinical study demonstrated that layering followed by injection molding resulted in predictable, highly esthetic, polychromatic, life-like restorations which can be consistently and efficiently reproduced in clinical situations.
Funding/Conflict of Interest: None
Keywords: esthetics, adhesives, composite resins, layering, injection molding
