12 July 2021

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10-year periodontal health study in short dental arch rehabilitations

Lara Figini

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As life expectancy continues, an increase in periodontal disease is also expected. In old patients, the concept of shortened or reduced dental arch (SDA) could offer options for solving these periodontal problems. The term SDA is commonly used to indicate the conditions in which all the anterior teeth are present up to both premolars on both sides, with the absence of molars. Over the past two decades, a substantial number of studies have added evidence to support the concept of SDA. On the contrary, numerous studies have shown that partial removable restorations (PRDP) in particular can have an unfavorable impact on periodontal health and therefore on the survival of residual teeth.

Materials and methods
A randomized controlled clinical trial, published in the Journal of Prosthodontic Research in October 2020, the authors compared periodontal health ten years later in patients who had lost molars and rehabilitated with removable appliances to replace molars or in which it was kept the dental arch reduced up to the second premolars. In the partial removable dentures (PRDP) group (n = 79), the molars were replaced with a precision attachment. In the SDA group (n = 71), the short dental arch was left up to the second premolars rehabilitated with fixed dental prostheses. Outcome variables were vertical clinical attachment loss (CAL-V), probing depth of pockets (PPD), bleeding on probing (BOP), and plaque index (PLI). For CAL-V and PPD, measurements were taken at six points for each tooth. Statistical methods included linear regression analysis

Results
In the 10-year analyzes, significant differences were found between the two groups for CAL-V, BOP and PLI but not for PPD. In the 10-year PRDP group there was an increase of 0.72 mm for CAL-V for all teeth and 0.66 mm for the maxilla analyzed. However, in the SDA group, there were hardly any changes over 10 years. For PPD, there were no significant differences between groups. Evaluation of BOP rates over time, for the PRDP group, showed a trend towards increasing values with time for all teeth and jaw analyzed in the study. On the other hand, this clear trend was not found in the SDA group. In the PRDP group, the evaluation of plaque percentages over time showed increasing values over time for all teeth, for the maxilla analyzed in the study and for the more posterior teeth of the maxilla analyzed in the study. In the SDA group, this trend was much less pronounced. Group differences over 10 years ranged from 5.97% to 11.36%.

Conclusions
From the data emerging from this study, which must be confirmed in other similar studies, it can be concluded that although there are differences in terms of periodontal health between the two rehabilitation solutions (PRDP vs SDA). both treatments can be considered viable options from a periodontal point of view. However, the results add further confirmatory evidence to the concept of SDA.

Clinical implications
The patient's subjective needs and preferences should be carefully weighed in clinical decision making along with biological and functional considerations when deciding for or against molar replacement with PRDP.

For additional information: Periodontal health in shortened dental arches: A 10-year RCT