Prefabricated CAD/CAM PEEK Crowns For Primary Molars Restoration

Evaluation of Minimally Prepared CAD/CAM Polyetheretherketone (PEEK) Crowns Efficacy in Restoring Primary Molars

This Split-mouth randomized clinical trial aims to evaluate CAD/CAM prefabricated Polyether ether ketone crowns for primary molars restoration after pulpotomy compared to Stainless steel crowns Over follow-up periods of 3, 6, and 12 months, the sample included 60 children aged 5-9 years who had bilateral mandibular second primary molars.

Each child received a pulpotomy treatment followed by the placement of a stainless steel crown on one side and a PEEK crown on the contralateral side, distributed randomly.

Clinical parameters were subsequently evaluated during the three follow-up periods, including the gingival index, plaque index, bleeding on probing index, restoration retention and integrity, marginal adaptation, color stability, and both parental and child satisfaction.

Interest in the esthetic aspect of pediatric dental treatment has increased among both children and parents, as children's self-perception is strongly influenced by the appearance of their teeth from an early age. Most esthetic restorative options require extensive tooth preparation compared with stainless steel crowns (SSCs). However, only limited studies have investigated conservative esthetic alternatives for primary molars.

This randomized controlled clinical trial aimed to evaluate the clinical effectiveness of CAD-CAM prefabricated esthetic PEEK crowns compared with stainless steel crowns (SSCs) in restoring primary mandibular second molars after pulpotomy. Clinical performance was assessed according to restoration retention and integrity, gingival health, plaque accumulation, bleeding on probing, marginal adaptation, color stability, and child/parent satisfaction over follow-up periods of 3, 6, and 12 months.

The sample was randomly allocated using the website: randomization.com

A total crowns were randomly distributed into four groups (n=20 per group):

(A): Prefabricated CAD/CAM PEEK crowns with 0.2 mm thickness (B): Prefabricated CAD/CAM PEEK crowns with 0.4 mm thickness (C): CAD/CAM fabricated PEEK crowns prepared according to NuSmile recommendations (D): Stainless steel crowns (SSC). The study included healthy, cooperative children aged 5-9 years requiring pulpotomy treatment for mandibular second primary.

Clinical Procedure

Clinical and radiographic examinations are performed to confirm the indication for pulpotomy treatment, followed by completion of the study form. Local anesthesia and rubber dam isolation are carried out, and pulpotomy is performed according to the conventional technique described by Dean (2016). The tooth is then restored with glass ionomer cement.

After cement setting, conservative tooth preparation is performed using diamond burs with 1-2 mm occlusal reduction. For Groups I, II, and IV, proximal reduction is completed with minimal preparation. In Group III, tooth preparation follows NuSmile recommendations, including occlusal reduction, proximal opening, crown reduction, and a 1 mm subgingival finish line.

For Groups I, II, and IV, the appropriate crown size is selected, checked for marginal adaptation and proximal contacts, then cemented using Fuji I glass ionomer cement. Excess cement is removed using a dental explorer and dental floss.

For the CAD/CAM fabricated PEEK group, a silicone impression is taken and scanned digitally. Crowns are designed using Exocad software and fabricated with CAD-CAM technology. After polishing and internal surface conditioning with aluminum oxide particles, the crown is tried in, cemented with Fuji I glass ionomer cement, and excess cement is removed.

Clinical parameters are evaluated immediately after crown cementation for directly measurable baseline variables and during the three follow-up periods (after 3, 6, 12 months), including the gingival index, plaque index, bleeding on probing index, restoration retention and integrity, marginal adaptation, color stability, and both parental and child satisfaction.

Inclusion Criteria:

1. Healthy children aged 5-9 years.
2. Children requiring pulpotomy of mandibular second primary molars.
3. Cooperative children rated as positive or definitely positive on the Frankl behavior scale.
4. No acute or chronic abscess at the anesthesia site.

Exclusion Criteria:

1. Root resorption exceeding the apical third.
2. Non-restorable teeth.
3. Presence of swelling, fistula, or acute or chronic pulpitis.