Objective: The aim of this study was to assess longitudinal quantitative changes in bone density around different implant loading protocols and implant surfaces measured by digital subtraction radiography (DSR). Methods: 12 patients received bilateral homologous standard and TiUniteH (Nobel Biocare, Kloten, Switzerland) single-tooth implants under 2 implant-loading protocols: immediate loading (8 patients, 16 implants, 12 maxillary) and conventional loading (4 patients, 8 implants, 4 maxillary). Standardized periapical radiographs were taken immediately after implant placement (baseline image) and at the 3-month, 6-month and 12-month follow ups. Radiographic images were digitized and submitted to digital subtraction using the DSR systemH (Electro Medical System, Nyon, Switzerland), resulting in three subtracted images. Quantitative analysis of bone density was performed using Image ToolH software (University of Texas Health Science Centre, San Antonio, TX) to assess pixel value changes in five areas around the implants (crestal, subcrestal, medial third, apical-lateral and apical). Results: Repeated-measures analysis of variance showed that grey levels were significantly influenced by follow-up time and implant-loading protocol. A linear increase in grey levels was found for immediate loading (IML) implants and a significant decrease in grey levels was observed in the 12-month follow up for conventional loading implants. No effect of implant surface treatment was observed. Conclusion: In conclusion, IML protocol induced mineral bone gain around single-tooth implants after the first year under function for cases with favourable bone conditions.

Os terceiros molares inferiores apresentam-se frequentemente retidos e suas raízes podem estar envolvidas pelo canal da mandíbula, representando risco de injúria nervosa durante a exodontia. Na avaliação pré-cirúrgica desses dentes, comumente utiliza-se a radiografia panorâmica, que muitas vezes evidencia a sobreposição das imagens das raízes dentárias sobre o canal da mandíbula, com possibilidade de proximidade entre estas estruturas. Esses casos geram dúvidas ao profissional quanto à necessidade de indicar uma tomografia computadorizada. Na literatura têm sido pesquisados achados na radiografia panorâmica que indicam maior risco de proximidade entre tais estruturas, justificando a indicação do exame seccional. Entre esses achados, destacam-se: escurecimento radicular, interrupção da linha radiopaca do canal, desvio do canal, deformação da raiz, estreitamento do canal, estreitamento radicular, escurecimento e ápice bífido da raiz. A presença de um ou mais desses sinais em radiografia panorâmica indica provável proximidade entre as raízes do terceiro molar e o canal mandibular. O objetivo desse trabalho foi relatar um caso clínico de avaliação do dente 48 previamente à exodontia, envolvendo uma radiografia panorâmica, que revelou dois desses sinais apontados na literatura. Posteriormente, foi obtida tomografia computadorizada por feixe cônico (TCFC), que evidenciou envolvimento de ambas as raízes do dente 48 pelo canal da mandíbula. Concluiu-se que a TCFC foi bem indicada, devendo ser recomendada quando a radiografia panorâmica evidenciar um ou mais dos sinais indicativos de proximidade entre raízes do siso e o canal da mandíbula, contribuindo para a decisão na rotina clínica e para evitar complicações pós-operatórias.

In the literature, several studies have investigated cone beam computed tomography (CBCT) findings of microscopically confirmed odontogenic keratocysts (OK). Such data can be useful on clinical routine in the diagnosis of bone lesions to define a hypothesis of OK before surgical resection. Objective: To report a clinical case of an extensive bone lesion in the mandible, which tomographic and clinical findings suggested OK as the first hypothesis. Case report: A 14-year-old male underwent a CBCT scan of the mandible for investigating an asymptomatic radiolucent bone lesion detected in a panoramic radiography. Clinically no swelling was evident and the adjacent teeth presented positive response to pulpal sensitivity test. CBCT images revealed a hypodense and unilocular lesion extending from mandibular left central incisor region to mandibular left first molar site; from jaw base to periapical region of the adjacent teeth; from buccal to lingual bone cortical. At the site of the lesion, there was erosion of the buccal and lingual bone cortical, which presented a mild expansion. Additionally, sectional images showed scalloped edges of the lesion, slight external root resorption at the apex of mandibular left second premolar, subtle incomplete septa and mandibular canal involvement by the lesion. Conclusion: The relevant CBCT findings contributed to suggest a probable hypothesis of OK in the diagnosis of a mandibular bone lesion. However, final diagnosis depends on microscopic examination.