For each individual tooth replacement our objective is to provide an almost identical replacement tooth in terms of shape, size, appearance and functional ability. Most people have 28-32 teeth in good health and the teeth vary considerably around the mouth with respect to function, anatomical shape and size. In an average mouth with 28 teeth there are at least 7 different types of tooth groups. These are:
- Upper central incisors
- Upper lateral incisors
- Upper canines
- Upper and Lower premolars
- Upper and Lower molars
- Lower canines
- Lower incisors
If this is the case then surely 1 type of dental implant can’t be the solution for all of these tooth replacements? The type of dental implant, in particular the uppermost part of the implant which connects to the overlying tooth restoration, is responsible for the type of tooth that can be provided.
LENGTH VS DIAMETER?
Dental Implant size is determined by 2 major parameters; the length and the diameter. This is of significant importance when providing a tooth replacement from one of the above tooth groups. For instance, we are more likely to want to use a wider diameter implant to replace a larger tooth such as a molar or upper central incisor. We may also want to use a shorter dental implant to avoid interfering with important anatomical structures such as maxillary sinuses and nerve canals – these assessments are made on our patient’s CBCT scans for precision planning.
TISSUE LEVEL VS BONE LEVEL?
Another important variable in dental implant selection is whether we should use a ’tissue level’ or a ‘bone level’ implant. A tissue level implant is easier to clean and maintain for the patient because the connection between the implant screw and the tooth restoration sits at the level of the gum line which is easy to access with a normal toothbrush. The only disadvantage of a tissue level dental implant is that the silver metal collar of the implant ‘may’ be visible around the gum line which would provide an aesthetic concern.
A ‘bone level’ dental implant is advantageous because it sits approximately 3-6 mm below the visible gum line which means that the connection between the implant screw and the restoration sits well below the visible gum margin. For this reason, these implants provide a more predictable and consistent aesthetic outcome for patients. The downside to this feature is that the connection between the implant and the restoration is harder to clean and maintain as it is below the gum margin and therefore harder to access with a normal toothbrush. Despite this, with thorough daily oral hygiene using flossing and tepe brushes, good cleaning can be maintained.
When planning our treatments we take all of this in to account and discuss the options with our patients. In most cases we find that tissue level implants are ideal to replace teeth at the back of the mouth where access for daily cleaning with flossing is generally more difficult than the front of the mouth. A possible silver collar around the gum line at the back of the mouth is not a disaster as it cannot be seen in normal function. We use bone level implants in most cases at the front because of the better aesthetics and also the fact that the front of the mouth is easier to clean more thoroughly due to ease of access.
The surface design of dental implants has evolved over the years. It is this surface that will be in contact with the patient’s bone therefore, advances in the design of this surface have significantly improved the bone to implant contact and the subsequent osseointegration. The image above shows a range of some of the implant shapes that are available to use. We can see that there is a varying degree of taper on these implants. All of these shapes offer solutions for the wide range of bone types we have to treat in the mouth. By selecting the correct tapering on each implant, we are able to influence so many factors such as the stability of the implant and the overall time it will take for the patient to have their final implant supported tooth fitted.
When providing dental implants to replace missing teeth our aim is to provide a lifelong tooth replacement. Surely this can only be achieved if we consider the long term implications that the potential implant will have on the patient’s ability to clean and function with this tooth.
Thank you for reading,
Mohsin Patel BDS MJDF RCS (Eng)