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Biomedical subjects

S Andreana

Publications and source records attributed to S Andreana.

15 recordsLinked to original sources

Role of the finite element model in dental implants.

Computer-aided design and finite element methods (FEM) have interested dental researchers because of its use in the computer simulation and design of dental implants, a process greatly facilitated by the development of new computer technology and more accurate modeling technologies. FEM allows for a better understanding of stresses along the surfaces of an implant and in surrounding bone. This will aid in the optimization of implant design and placement of the implant into the bone; it will also help when designing the final prostheses to minimize stresses. The purpose of this review is to elucidate the role of FEM and the impact of this technology in clinical dentistry in the new millennium.

Dental Implantation, Endosseous↗

A combined approach for treatment of developmental groove associated periodontal defect. A case report.

Developmental grooves are not rare and often appear on maxillary lateral incisors. This may represent a challenge and sometimes tooth extraction is inevitable. This case report describes a combined technique of regenerative and antimicrobial/root conditioning used to treat a maxillary lateral incisor in a 32-year-old woman. Tooth #10 presented a periodontal probing depth of 8 mm below the cingulum, associated with a developmental groove. The tooth was vital. After initial preparation, a palatal mini-flap was raised, granulation tissue was eliminated by means of ultrasonic bactericidal curettage and radicoloplasty performed. The surface was then treated for 3 minutes with tetracycline-HCl solution (100mg/ml), and the defect filled with sterile, medical grade, calcium sulfate. Clinical measurements were retaken at 6, 12, and 18 months. The results indicated a reduction of probing depth to 2 mm, reestablishment of the lamina dura, and radiographical evidence of bone growth. This combined treatment allowed the tooth to be saved, the palatal surgical approach did not alter the esthetics of the area, and its simplicity is recommended.

Adult↗

Periodontal tissue regeneration in beagle dogs after laser therapy.

BACKGROUND AND OBJECTIVE: Class III periodontal furcations still represent a challenge for the periodontist. Aim of this study was to test the effect of CO2 laser on the treatment of class III furcation defects. STUDY DESIGN/MATERIALS AND METHOD: Class III furcation defects 3 mm deep were surgically induced on mandibular premolars on six male Beagle dogs, for a total of 36 defects. After 6-8 weeks of plaque accumulation, the mean depth was 6.8 mm. Quadrants were randomly assigned to a) CO2 laser therapy (laser), b) Guided Tissue Regeneration (GTR) procedure using Gore-Tex Membranes, (Gore Tex, Flagstaff, Arizona, USA) and c) Scaling and Root planing (Sc/Rp). CO2 laser beam (El.En, Florence, Italy) was applied to the root surfaces in defocused pulsed mode at 2W, 1 Hz and a duty cycle of 6%, and on periodontal soft tissues at 13W, 40 Hz, and a duty cycle of 40%. Control quadrants received either GTR procedure or Sc/Rp. Mechanical oral hygiene was provided. At 6 months the animals were sacrificed. RESULTS: The laser group showed new attachment formation averaging 1.9 mm (sd +/- 0.5), whereas GTR and Sc/Rp showed 0.2 mm (sd +/- 0.4) and 0.2 mm (sd +/- 0.5) respectively, being the differences statistically significant between the laser group and both GTR and Sc/Rp groups (p < 0.005). CONCLUSION: CO2 laser treatment of class III furcation induced formation of new periodontal ligament, cementum and bone.

Alveolar Bone Loss↗

Bone regeneration with a calcium sulfate barrier.

OBJECTIVES: Bone defects are a challenge for the dental clinician. As widely accepted in guided tissue regeneration, physically halting soft connective tissue proliferation into bone allows for bone regeneration. This concept is the "osteopromotion principle." The aim of this study was to assess the osteopromoting effect of calcium sulfate as a barrier. STUDY DESIGN: Forty male Sprague-Dawley rats were used. Mucoperiosteal flaps were raised bilaterally at buccal and lingual aspects of the mandible to expose the angles. Next, 5 mm through-and-through bony defects were created bilaterally. On the test side, sterile medical grade prehardened calcium sulfate disks were applied both lingually and buccally to cover the defect. The control side defects were left uncovered. All flaps were sutured closed. Observation times were 3, 9, 18, and 22 weeks. RESULTS: Histologic analysis demonstrated that at 3 weeks all test sites showed partial or complete bone healing. Similar findings were reported for all observation times. The control group showed no bone growth at 3 and 9 weeks and partial bone healing at 18 and 22 weeks. CONCLUSIONS: This study indicates that calcium sulfate barriers can exclude connective tissues, allowing bone regeneration during healing.

Alveolar Process↗

Effects of smoking and smoking cessation on healing after mechanical periodontal therapy.

This study investigated the effect of cigarette smoking on 143 patients' clinical and microbiological responses to mechanical therapy. Treatment included four to six sessions of subgingival scaling and root planing and instruction in oral hygiene. Results indicate that current smokers have less healing and reduction in subgingival Bacteroides forsythus and Porphyromonas gingivalis after treatment compared to former and nonsmokers, suggesting that smoking impairs periodontal healing. As the healing and microbial response of former smokers is comparable to that of nonsmokers, smoking cessation may restore the normal periodontal healing response.

Adult↗

New directions in surgical endodontics; immediate implantation into an extraction site.

Endodontic surgical procedures may reveal compromising factors that indicate a modification of the treatment (e.g. tooth extraction, root amputation, etc.). To take advantage of the osseous height and width, as well as the natural tooth angulation, immediate placement of implants after extraction is a reasonable alternative treatment. In this study, 32 titanium alloy implants were inserted immediately after extraction of teeth diagnosed during endodontic surgery as having root fractures, perforations, or endodontic-periodontal complications. After 4 to 6 months of osseointegration, only one implant failed to integrate, and the remaining implants were prosthetically restored. Sixteen months after occlusal loading, bone loss was approximately 1.5 mm for the 31 implants remaining. It seems that the immediate placement of implants following tooth extraction due to endodontic complications is a reliable procedure.

Adult↗

Topographic distribution of subgingival plaque along root surfaces of human periodontally diseased teeth. A descriptive study.

The purpose of this study was to characterize the topographical distribution and organization of subgingival plaque in periodontally diseased teeth. 26 extracted teeth were fixed and processed for undecalcified histological evaluation. The sections were cut perpendicular to the long axis of the tooth and analyzed by phase-contrast microscopy. The coronal portion of the analyzed roots showed a dense accumulation of filamentous forms, fusiform rods, coccoid forms and loosely aggregated spirochetes. The middle and apical portions showed a non-uniform distribution of the microflora, with microorganisms representing all the known morphotypes. Furthermore, plaque was detected below undisturbed periodontal fibers, indicating that plaque not only forms apically, but also in a lateral direction, penetrating and colonizing below areas where periodontal fibers are inserted into the root surface.

Adult↗

Thomas Berdmore, dentist of His Majesty, George III, and dental calculus.

Thomas Berdmore's book, Disorders of Deformities of the Teeth and Gums, presents examples of early concepts of preventive dentistry and treatment of periodontal diseases. Various aspects of dental calculus formation and composition are analyzed. Also the effects of periodontal disease as seen by Berdmore are discussed, and ways of treatment in 1770 summarized.

Dental Calculus↗

[Not Available].

Explore the source record for details and available documents.

Dental Materials↗

Use of dental operating microscope in endodontic surgery.

Endodontic surgery is an alternative therapeutic approach to endodontic treatment. The outcome of the technique is affected by several factors, some of which can be eliminated by the use of a dental operating microscope. The microscope was used during the performance of 50 apicoectomies, with or without retrograde fillings. For clinical evaluation cases treated with the dental operating microscope were compared to cases treated without it. The postoperative evaluation showed a reduced incidence of symptoms in the cases treated with the dental operating microscope. More important, the dental operating microscope enhanced and facilitated each phase of endodontic surgery. Its use is highly recommended.

Apicoectomy↗

Simultaneous implant placement and vertical ridge augmentation with a titanium-reinforced membrane: a case report.

The present report demonstrates a clinical approach to achieve vertical ridge augmentation around endosseous implants. Two implants were placed, leaving the threads exposed, in the atrophic mandibular right posterior quadrant of a male patient. Both implants were covered with a titanium-reinforced expanded polytetrafluoroethylene (e-PTFE) membrane. Second-stage surgery was performed 12 months after implant placement. Upon membrane removal, growth of mineralized tissue was observed around both implants, covering areas previously not covered by bone. Implants were then progressively loaded and restored. Titanium-reinforced e-PTFE membranes can be satisfactorily used for vertical augmentation of atrophic ridges.

Alveolar Ridge Augmentation↗

Osseointegration of rough acid-etched implants: one-year follow-up of placement of 100 minimatic implants.

Between January 1992 and October 1992, 100 Minimatic screw implants made of titanium alloy with rough acid-etched surfaces were placed in 63 consecutive partially edentulous patients. At second-stage (uncovering) surgery performed after a 4- to 6-month healing period, none of the implants showed any signs of mobility, peri-implant infection, or bone loss. After an additional healing phase averaging 2 weeks, the patients were restored with fixed prostheses. Patients were reexamined every 3 months for 1 year, with all 63 patients available for evaluation during this period. Periapical radiographs were taken preoperatively, immediately after surgery, and at 6 and 12 months after implantation. There were no signs of peri-implant radiolucencies in any of the implants, and alveolar bone loss was less than 1 mm on average 1 year after implantation. Based on Plaque Index, sulcular bleeding index, pocket probing depth, attachment level, width of keratinized mucosa, and hand-tested mobility, 99 implants were considered successful and 1 (which developed peri-implant infection) was considered a failure. Study results substantiate other reports that implants with a rough surface can yield predictable good results.

Alloys↗