Blog | Finlay Sutton - Denture Education

Flexible dentures are bad

I don't provide flexi-dentures as I believe they go against all prosthodontic principles of preservation of the periodontium as they twist and flex during chewing. A stiff major connector in cobalt chromium works in the same way a car chassis does. High performance cars have a rigid chassis allowing the suspension to work properly improving the handling of the car. A rigid major connector allows the rest seat, clasp and reciprocal assembly to work properly under occlusal loading, limiting the harm to the abutment teeth, periodontium and supporting soft tissues and as a result improve patient comfort when chewing.

I think they may be of use as short term temporary measures prior to definitive treatment, such as during implant integration or provision of a definitive cobalt chromium based denture.

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Partial dentures – shapes of saddles

In general, making edentulous saddles similar in shape and extension to that of a complete denture maximises the retention, support and stability of removable partial dentures. For instance, in mandibular free end saddle partial dentures (Kennedy Classes I and II), extending the saddle over the retromolar pad improves the retention of the lower by allowing the soft tissues of the cheek and the tongue to sit on top of the polished surface, stabilising it rather like a “sandbag”.

In edentulous areas located in the anterior region (Kennedy Class IV) the saddle extension gives the best lip support if extended to the depth of the sulcus under the base of the nose. Not sure I agree with this general statement. In addition, maximising the extension of the saddle allows greater distribution of masticatory forces over the supporting soft tissues, rather like a snow shoe compared with a stiletto heel.

These shapes are generated in the definitive impression stage, by border moulding correctly extended special trays.

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Precision attachments are rarely needed for partial dentures

Precision attachments are not easy to incorporate into partial dentures. They have many disadvantages and require careful planning with mounted study models and prototype diagnostic set ups. Additionally, they are expensive and require careful time-consuming execution, especially in the lab; this is expensive, too

These are the main disadvantages I find with precision attachments:

1. Space is always a big problem as the attachment often gets in the way of positioning the artificial tooth in the best position. Denture attachments are often too large.

2. Abutment support teeth often need a full coverage restoration with all the disadvantages of increasing the restorative burden.

3. They considerably add to the expense of the prosthesis.

4. They require more maintenance than conventionally supported/retained partial dentures being similar to implant supported dentures, with the added complication of the restored tooth support.

5. Increased manual dexterity is required for oral hygiene procedures around the attachment.

6. They are much more technique sensitive to execute.

When executed well they can have two advantages over conventional removable partial dentures:

1. No visible clasps – retention is hidden

2. They can be more retentive than conventional partial dentures – with improved chewing and biting function.

As a result of the many disadvantages I very rarely use them. I find that providing guiding surfaces and well positioned rest seats on the support teeth lead to partial dentures which are stable and well retained without needing to resort to the added complicating factors precision attachments bring.

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Finlay's Voices From The Bench Podcast 2022

Do you struggle getting the correct records to do your best removable restorations? Elvis & Barbara have just the two to help. Jeremiah Naas is a technician turned Denturist. Always wanting to improve his technique (both clinically and as a technician), Jeremiah wanted to bring an amazing removable prosthesis ”Clinical Dental Technician” from England over to teach a course. Finlay Sutton was trained as a dentist, but discovered he had a unique ability to restore the patients deemed “not restorable”. Together they talk about interesting cases, patient challenges, and what to expect from next year’s course.

Visualise the denture space before taking primary impressions

I look in the mouth before taking a primary impression. I look at the depth and width of the sulcus. I rehearse the process of taking the impression and imagine the material filling this space in a smooth roll.

Visualising the denture space helps me produce better primary impressions enabling the production of correctly extended custom trays.

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Soft linings (Molloplast B) with complete dentures need metal reinforcement

Bruxism still occurs in edentulous patients – particularly in psychologically stressed patients. This can be problematic underneath complete lower dentures, often resulting in trauma and support problems. A complete denture with a soft lining can be weak owing to being thin in cross-section. When this is combined with heavy occlusal forces from bruxism it can lead to fracturing of the denture base. As a result of having had this occur on several occasions, I now ROUTINELY reinforce these dentures with a T-shaped cobalt chromium cage (if there is space) or if it is thin a cobalt chromium lingual plate.

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Partial dentures – dubious prognosis abutment teeth

Partial dentures with metal-based frameworks should be designed to permit easy addition of denture teeth in the future, allowing any tooth with questionable prognosis to be kept initially, while, for example, the patient’s oral health improves.

In the event of a tooth requiring extraction, the prosthetic replacement tooth can be attached securely to the backing via a welded metal retentive tag.

This saves the expense of having to remake the metal based RPD.

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Dealing with unhappy patients

Listen to them and do not interrupt. Do not ever let the “lizard”, “chimp” or “child brain” (flight, fight response) deal with it.

It’s the job of prefrontal cortex to deal with the situation compassionately.

I try to learn from my mistakes.

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