Libros

Aims: Missing single teeth can be treated in several ways and preoperative radiological evaluation varies accordingly. The main area of controversy relates to the need for cross-sectional imaging in the context of implant treatment. In this context, the aim of the systematic component of this review was to determine whether the use of additional cross-sectional imaging has any impact on diagnostic thinking, treatment planning or outcome, compared with conventional imaging alone. An additional aim was to present information relating to diagnostic efficacy, dose of radiation, economic aspects of imaging and selection criteria. Materials and methods: PubMed/MEDLINE, OVID/Embase and the Cochrane central register of controlled trials were searched up to and including June 2015. Studies were eligible for inclusion if they compared the impact of conventional and cross-sectional imaging when placing implants. Quality assessment of studies was performed. Synthesis was qualitative. Results: Twelve studies were included, all of which had a 'before-after' design. Only three of these were limited to single implant treatments with none limited to immediate implants. There were methodological problems with most of the studies and results were sometimes contradictory regarding the impact of cross-sectional imaging. Conclusions: It is tentatively suggested that cross-sectional imaging may not be required in straightforward, unchallenging, cases of missing single teeth being considered for implant treatment. Beyond this, no strong evidence exists to inform the choice of imaging. Existing guidelines on preoperative imaging for missing single teeth are not unanimous in their recommendations, either for implant or non-implant treatments. Palabras clave: dental implants, diagnostic imaging, edentulous, jaw, partially, patient selection, radiology

Purpose: To investigate the effect of platelet-rich plasma (PRP) on the healing of hard and soft tissues of extraction sockets with a pilot study. Material and methods: Patients undergoing tooth extraction under intravenous sedation were asked to participate in the trial. Autologous platelet concentrates were prepared from the patients' blood and autologous thrombin was produced. Outcome measures were: pain level, analgesic consumption, oral function (ability to eat food, swallowing, mouth opening and speech), general activity, swelling, bruising, bleeding, bad taste or halitosis, food stagnation, patient satisfaction, healing complications, soft tissue healing, trabecular pattern of newly formed bone in extraction sockets, trabecular bone volume, trabecular separation, trabecular length, trabecular width, and trabecular number. Patients were followed up to 3 months post-extraction. Results: Twelve patients (15 sockets) were randomly allocated to the PRP group and 11 patients (14 sockets) to the control group. Two patients from the control group did not attend any of the scheduled appointments following tooth extraction, and were considered dropouts. Additionally, one more patient from the control group and four patients from the PRP group did not attend their 3-month radiographic assessment appointments. Statistically significantly more pain was recorded in the control group for the first (P = 0.02), second (P = 0.02) and third (P = 0.04) post-operative days for Visual Analogue Scale scores, whereas no differences were observed for the fourth (P = 0.17), fifth (P = 0.38), sixth (P = 0.75) and seventh (P = 0.75) post-operative days. There was a statistically significantly higher analgesic consumption for the first (P = 0.03) and second (P = 0.02) post-operative days in the control group and no differences thereafter. Differences in patients' responses in the health-related quality of life questionnaire were statistically significant in favour of PRP treatment only for the presence of bad taste or bad smell in the mouth (P = 0.03), and food stagnation in the operation area (P = 0.03). The difference between groups was not statistically significant for patient satisfaction with the treatment (P = 0.31). Regarding complications, two dry sockets and one acutely inflamed alveolus occurred in patients of the control group, which determined a borderline statistically significant difference in favour of the PRP group (P = 0.06). Soft tissue healing was significantly better in patients treated with PRP (P = 0.03). Radiographic evaluation carried out by the two blinded examiners revealed a statistically significant difference (P = 0.01) for sockets with dense homogeneous trabecular pattern, a borderline statistically significant difference in the trabecular pattern for bone volume (P = 0.06) favouring PRP use, and no significant differences for trabecular separation (P = 0.66), trabecular length (P = 0.16), trabecular width (P = 0.16) and trabecular number (P = 0.38). Conclusions: PRP may have some benefits in reducing complications such as alveolar osteitis and improving healing of soft tissue of extraction sockets. There were insufficient data to support the use of PRP to promote bone healing or to enhance the quality of life of patients following tooth extraction, although the sample size was too small to detect statistically significant differences. Palabras clave: extraction socket, healing, platelet-rich plasma, quality of life, radiographs

Purpose: This randomised double-blind placebo-controlled trial was carried out to investigate the effect of a one-week post-operative course of 600 mg of ibuprofen taken four times a day on marginal bone level around dental implants. Materials and methods: A total of 61 patients were allocated to the ibuprofen (31 patients) or placebo group (30 patients). Overall, 132 implants were inserted, 67 implants in the ibuprofen group and 65 implants in the placebo group. Preparation of the implant sites was carried out with an intermittent drilling sequence adapted to the fixture diameter and the local bone quality according to the Astra Tech implant installation guide. The primary outcome measure was the change in marginal bone level around dental implants from the baseline (2 weeks post-placement) to the 3- and 6-month radiographic examinations. The paralleling technique and a film holder coupled to a beamaiming device were used to take the periapical radiographs. Measurement of changes in bone level was made using a viewing box and ×8 magnifier. Results: Two patients from the ibuprofen group were unable to complete the prescribed course of ibuprofen owing to a minor self-reported stomach upset. A patient from the control group did not attend any of the scheduled appointments following implant placement. A total of three patients dropped out. All implants survived in either group during the 6-month observation period. The mean marginal bone level changes from the baseline were (-0.33 mm) at the 3-month and (-0.29 mm) at the 6-month follow-up for the ibuprofen group while the corresponding values for the placebo group were (-0.12 mm) and (-0.30 mm). There were no statistically significant differences between groups for mean marginal bone level changes at 3 months (P = 0.27) or 6 months (P = 0.97). Conclusions: Administration of a short course of systemic ibuprofen for post-operative pain management subsequent to implant placement may not have a significant effect on the marginal bone around dental implants in the early healing period. Palabras clave: dental implants, ibuprofen, marginal bone, periapical radiograph, placebo

Purpose: The purpose of this study was to derive alternative implant shapes which could minimize the stress concentration at the shoulder level of the implant. Materials and Methods: A topological shape optimization technique (soft kill option), which mimics biological growth, was used in conjunction with the finite element (FE) method to optimize the shape of a dental implant under loads. Shape optimization of the implant was carried out using a 2-dimensional (2D) FE model of the mandible. Three-dimensional (3D) FE analyses were then performed to verify the reduction of peak stresses in the optimized design. Results: Some of the designs formulated using optimization resembled the shape of a natural tooth. Guided by the results of the optimization, alternative implant designs with a taper and a larger crestal radius at the shoulder were derived. Subsequent FE analyses indicated that the peak stresses of these optimized implants under both axial and oblique loads were significantly lower than those observed around a model of commercially available dental implant. Conclusion: The new implant shapes obtained using FE-based shape optimization techniques can potentially increase the success of dental implants due to the reduced stress concentration at the bone-implant interface. Palabras clave: crestal bone loss, dental implant, finite element analysis, shape optimization