Fabrication Of Occlusal Rims Introduction
This chapter explains fabrication of wax occlusal rims using rolled wax technique. This is the most commonly used method for fabrication of occlusal rims. Follow the procedure step by step for accurate fabrication of occlusal rims.
Table of Contents
Armamentarium
Maxillary and mandibular master casts with record base.
- Modeling wax
- Pencil or marker pen
- Bunsen burner
- Wax knife
Read and Learn More: Preclinical Prosthodontics Notes
- Wax carver
- Wax spatula
- Hot plate
- Metallic scale.
Fabrication Of Maxillary Occlusal Rim
Step 1:
Take a sheet of modeling wax. Heat it over the flame of Bunsen burner to soften it. Fold it from one end (approximately 0.5 cm). Take care not to melt it. Continuously soften it and roll it to prevent air bubble entrapment during rolling.
Step 2:
Roll the full wax sheet to get wax roll of diameter of around 2–3 cm. Place one end of the rolled wax on posterior aspect of record base (maxillary tuberosity) and follow the arch contour till the other posterior end.
Step 3:
Apply downward pressure on wax roll by holding it in between index finger and the thumb to extend it along the borders. Follow the arch contour while doing this to maintain the arch.
Step 4:
Give inside to outward push (thrust) in anterior region. This is done to give inclination to anterior rim. The inclination (protrusion) should be 12–15°. Due to inclination, maxillary rim becomes thinner anteriorly compared to posteriorly.
Step 5:
Seal the adapted wax on buccal and lingual peripheries using hot wax spatula or wax knife. Add or remove wax to fill up voids, spaces, and irregularities. Smooth the buccal surface maintaining the arch.
Step 6:
Cut the wax roll if extended over the maxillary tuberosity.
Step 7:
Measure the height of occlusal rim in canine area. Mark it 2–3 mm more than required height.
Step 8:
Reduce the excess height by using hot plate. Perform this procedure very slowly and frequently check the plane during the reduction. The hot plate is used for reduction of height and to make plane of occlusion.
Step 9:
Make anterior height 20–22 mm in canine region and posterior height 18 mm in molar region from border of record base. Adjust the anterior width 5–6 mm and posterior width 8–10 mm.
Step 10:
Remove excess wax from the borders. Check the tissue surface of record base, it should be free of any wax. The labial, buccal, and lingual surfaces of occlusal rim should be smooth and polished.
Fabrication Of Mandibular Occlusal Rim
Step 1:
Take a sheet of modeling wax. Heat it over the flame of Bunsen burner to soften it. Fold it from one end (approximately 0.5 cm). Take care not to melt it. Continuously soften it and make a wax roll.
Step 2:
Place one end of the rolled wax on posterior aspect of record base (retromolar pad) and follow the arch contour till the other posterior end.
Step 3:
Apply downward pressure on wax roll by holding it in between index finger and the thumb to extend it along the borders. Follow the arch contour while doing this to maintain the arch.
Step 4:
Seal the adapted wax on buccal and lingual peripheries using hot wax spatula or wax knife. Add or remove wax to fill up voids, spaces, and irregularities. Smoothen the buccal surface maintaining the arch form.
Step 5:
Position the wax rim on mandibular ridge according to guiding lines. The rim should be extended till anterior aspect of retromolar pad. Position the wax rim equally on the buccal and lingual aspect of the crest of the ridge.
Step 6:
Mark the height of 16 mm in canine region. Posteriorly height of wax rim is till two thirds of height of retromolar pad. Reduce the height accordingly with hot plate.
Step 7:
Width in anterior region is 5–6 mm and in posterior region it is 8–10 mm. Finished and polished maxillary and mandibular wax rims.
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