Читать книгу Periodontics - Fernando Suarez - Страница 96

Root concavities are common features of the root configuration and act as predisposing sites for periodontal breakdown.⁷⁰ Additionally, the presence of these developmental depressions will impair mechanical instrumentation during nonsurgical and surgical therapy, especially for multirooted teeth.

Fox and Bosworth conducted a morphologic assessment to determine the presence of proximal concavities on extracted teeth among all tooth types.¹¹⁰ The authors concluded that nearly every tooth has concavities at or within 5 mm apical to its CEJ.¹¹⁰ For multirooted teeth specifically, Booker and Loughlin reported mesial concavity depths of 0.35 mm and 0.44 mm associated with single-rooted and two-rooted maxillary first premolars, respectively.⁷⁴ Generally, these depressions tend to be deeper on the mesial aspects and middle third of the root surface.⁷⁵ Conversely, Gher and Vernino reported a prevalence of 78% of concavities around maxillary premolars being not clinically relevant until 50% of interproximal bone loss had occurred.⁷⁰

Bower also extensively explored the concavity depth and incidence around maxillary and mandibular first molars.¹¹¹ Within the maxillary first molar, concavities are more likely found on mesiobuccal (94%) than distobuccal (31%) or palatal (17%) root surfaces. A higher incidence was also noted among mandibular first molars on both mesial (100%) and distal (99%) root surfaces (Table 5-7).^74,111

TABLE 5-7 Prevalence and root concavity depth around maxillary and mandibular molars^74,111