Nondestructive methods for recovery of biological material from human teeth for DNA extraction.

The extraction of DNA from human skeletal remains applied to forensic, and evolutionary studies do not exclude risks, which are to be evaluated when working with unique specimens that could be damaged or even destroyed. In the present study were evaluated several nondestructive methods for recovering DNA instead of the most currently used pulverization method. Three different procedures to access inside the dental pieces (occlusal perforation, cervical perforation, and cervical cut) have been compared with the aim of recovering as many cell remains as possible to carry out a DNA extraction. Given the DNA quantitation results, a method was proposed that consists of a cervical cut to facilitate the access to the pulp cavity and a subsequent filing of the root canals down to the apex of the dental root. This methodology allows the recovery of both mitochondrial and nuclear DNA, with the minimum deterioration for the dental pieces.

Osteotome sinus floor elevation without grafting material: Results of a 2-year prospective study.

OBJECTIVES: The aim of this prospective clinical trial was to evaluate the success implant rates during 24 months using OSFE procedure without grafting materials. STUDY DESIGN: 42 adult patients (22 female, 15 male) were selected according to Nedir et al´s inclusion criteria of which 5 patients were excluded, due to periapical pathology in adjacent teeth (n=3) and treatment with bisphosphonates (n=2). 37 patients aged 31-68 years were selected. Smokers were divided in two groups depending on the number of cigarettes consumed per day (a) 0-10, (b) 11-20. One patient was excluded because he was lost to follow-up at 24 months A total of 36 threaded implants were placed, ∅4,1mm Straumann® (Straumann AG, Waldenburg, Switzerland) and ∅3,5mm Klockner® (Klockner Implant System, Barcelona, Spain). The most used implant diameter was 4,1 mm (n=29), followed by 3,5 mm (n=7), and length used was 10 mm (n=32) and 8 mm (n=4). Initial RBH ranged from 4 mm to 9 mm. All statistical data were processed using the program R 3.0.2 for windows. RESULTS: A total of 36 threaded implants were placed. Residual bone height (RBH) at implant placement averaged 7,4 ± 0,4 mm. Mean bone gain was 1,8 ± 0,3 mm. Four implants showed a bone gain exceeding 3 mm. Mean implant protrusion length into the sinus amounted to 2.1 ± 0,3 mm. Regarding the relationship between smoking and periodontal probes, no statistically significant differences were found (P=0,25), neither in relation to the number of threads that the implants showed (P=0,29) or bone gain (P=0,79). After 24 months the implant success rate was 91,6%. CONCLUSIONS: Implant rehabilitation of edentulous atrophied posterior maxilla can be safely performed and simplified using the OSFE technique without grafting with reliable long-term results. Key words:Crestal bone loss, dental implants, internal sinus lift, no grafting, osteotome sinus elevation, grafting, sinus floor elevation.