The pontic, \pŏn΄tĭk\, is an artificial tooth on a fixed partial denture that replaces a missing natural tooth, restores its function, and usually restores the space previously occupied by the clinical crown. An ideal correctly designed posterior pontic should have the following features.
- All surface should have convexity with proper finish.
- The contact with buccal contiguous slop should be minimal (pinpoint)) and with pressure free (modified ridge lap).
- Buccal and lingual shunting mechanism should conform with those of the adjacent teeth.
- Occlusal table should be in functional harmony with the occlusion of all of the teeth.
- The overall length of the buccal surface should be equal to that of the adjacent abutment teeth or pontic.
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| Figure 1. Schematic presentation of various pontic designs; (a) Sanitary pontic; has no contact with the edentulous ridge, (b) ridge lap pontic; forms a large concave contact replacing the contours of a missing tooth, (c) modified ridge lap; shows illusion of a tooth but it has all or nearly all convex surfaces for easy cleaning and minimize plaque accumulation, (d and e) bullet/conical; rounded and cleanable smaller tip in relation to overall size, (f) ovate; round end design currently in use where aesthetics is a primary concern[1]. |
The Pontic design can be classified into two types.
A. Pontic having mucosal contact
- Sanitary/Hygienic/Fish-belly and
- Modified sanitary type
B. Pontic with no mucosal contact
- Saddle/Ridge lap
- Modified Ridge Lap
- Conical
- Ovate
Sanitary or Hygienic Pontic or Fish-Belly
Sanitary pontic makes no contact with the edentulous ridge. It is made in an all-convex configuration, faciolingually and mesiodistally. The space between the pontic and the mucosa should be 2 or 3 mm[2]. It is most commonly used in mandibular molar replacement. It has the advantage of providing good access for maintaining hygiene with the disadvantage of poor esthetics.
Modified Sanitary
The tissue facing surface of the modified sanitary design pontic has a hyperbolic parabola. The pontic is designed as a concave archway mesiodistally while the under surface is convex faciolingually. It in indicated in molar replacement, provides access to undersurface for good hygiene, alongwith poor esthetics.
Saddle/Ridge Lap
It looks like crown of the tooth because it replaces all the contour of the missing tooth. It maintains a large concave contact with the underlying ridge and obliterates facial, lingual and proximal embrasures. Esthetic wise it provide best result but due to impossible access to under surface for cleaning, its use is limited for the replacement of maxillary incisors.
Modified Ridge Lap
Modified ridge lap combines esthetics with easy cleaning, and makes contact with ridge tissues in a shape of ‘ T ‘ whose vertical arm ends at the crest of the ridge. This design is most commonly used in the area of the mouth that is visible during function, e. g. anterior teeth, premolars and sometimes maxillary molars.
Conical
Conical pontic design is mostly limited to the replacement of thin knife edged ridges in the non-display zone of the mouth. It has a convex surface with only touching the centre of the residual alveolar ridge. It helps maintain good hygiene with poor esthetics. Conical design in indicated for the replacement of molars.
Ovate
Ovate pontic design is the most aesthetically suitable appealing design that looks like emerging from the gingiva. When ridge resorption is corrected by ridge augmentation, ovate design appears to be emerging through gingiva just like natural tooth. it is indicated for the replacement of maxillary incisors, canines, and premolars. It has the advantage of best esthetics, negligible amount of food entrapment and easy cleaning. The disadvantage is the requirement of surgical preparation of the receiving site before prosthesis fabrication.
There are MCQs on pontic design in “Free silver Course“, which you may like to attempt.
References:
- Eur J Dent. 2018 Jul-Sep; 12(3): 375–379. doi: 10.4103/ejd.ejd_232_18
- Rosenstiel & Tyllman respectively
- Pontics