Radiographic Study of Transcrestal Sinus Floor Elevation Using Osseodensification Technique with Graft Material: A Pilot Study.

This pilot study aimed to evaluate the level of implant success after transcrestal sinus floor elevation (tSFE) using the osseodensification technique (OD) combined with beta-tricalcium phosphate (ß-TCP) by analyzing clinical and radiographic results. Moreover, the increase in bone height was analyzed immediately after surgery, 3 months after, and before loading by taking standardized radiographic measurements. Thirteen patients, four males and nine females, with a mean age of 54.69 ± 5.86 years, requiring the placement of one implant in the upper posterior maxilla, with a residual bone height of <8 mm and a minimum bone width of 5 mm, participated in the study. The bone gain data was obtained using cone-beam computed tomography (CBCT) immediately after surgery and twelve months after the placement. The correlation between initial and final bone height with implant stability was also assessed. The results were analyzed using SPSS 23 software (p < 0.05). The results of the study indicated a 100% implant success rate after a follow-up period of twelve months. Preoperative main bone height was 5.70 ± 0.95 mm. The osseodensification technique allowed a significant increase of 6.65 ± 1.06 mm immediately after surgery. After a twelve-month follow-up, a graft material contraction of 0.90 ± 0.49 mm was observed. No correlation was observed between the bone height at the different times of the study and the primary stability of the implant. Considering the limitations of the size sample of this study, the osseodensification technique used for transcrestal sinus lift with the additional bone graft material (ß-TCP) may provide a predictable elevation of the maxillary sinus floor, allowing simultaneous implant insertion with adequate stability irrespective of bone height limitations.

A Biomechanical Analysis of the Influence of the Morfology of the Bone Blocks Grafts on the Transfer of Tension or Load to the Soft Tissue by Means of the Finite Elements Method.

Edentulism produces resorption of alveolar bone processes, which can complicate placement of dental implants. Guided bone regeneration techniques aim to recover the volume of bone. These treatments are susceptible to the surgical technique employed, the design of the autologous block or the tension of the suture. These factors can relate to major complications as the lack of primary closure and dehiscence. The present study, using finite element analysis, aimed to determine differences in terms of displacement of the oral mucosa, transferred stress according to Von Mises and deformation of soft tissue when two block graft designs (right-angled and rounded) and two levels of suture tension (0.05 and 0.2 N) were combined. The results showed that all the variables analyzed were greater with 0.2 N. Regarding the design of the block, no difference was found in the transferred stress and deformation of the soft tissue. However, displacement was related to a tendency to dehiscence (25% greater in the right-angled/chamfer design). In conclusion different biomechanical behavior was observed in the block graft depending on the design and suture tension, so it is recommended to use low suture tension and rounded design. A novel finite element analysis model is presented for future investigations.

Logistic Regression Analysis of the Factors Involved in the Failure of Osseointegration and Survival of Dental Implants with an Internal Connection and Machined Collar: A 6-Year Retrospective Cohort Study.

BACKGROUND: Although the long-term success rate of dental implants is currently close to 95%, it is necessary to provide more evidence on the factors related to the failure of osseointegration and survival. PURPOSE: To establish the risk factors associated with the failure of osseointegration and survival of dental implants with an internal connection and machined collar and to establish a predictive statistical model. MATERIALS AND METHODS: An analytical, retrospective, and observational clinical study of a sample of 297 implants with a follow-up of up to 76 months. Independent variables related to the implant, patient, and surgical and rehabilitative procedures were identified. The dependent variables were failure of osseointegration and failure of implant survival after prosthetic loading. A survival analysis was carried out by applying the Kaplan-Meier model (significance for p < 0.05). The log-rank test and the Cox regression analysis were applied to the factors that presented differences. Finally, the regression logit function was used to determine whether it is possible to predict the risk of implant failure according to the analyzed variables with the data obtained in this study. RESULTS: The percentages of osseointegration and survival were 97.6 and 97.2%, respectively. For osseointegration, there were significant differences according to gender (p = 0.048), and the risk of nonosseointegration was 85% lower in women. Regarding survival, the Cox analysis converged on only two factors, which were smoking and treatment with anticoagulant drugs. The risk of loss was multiplied by 18.3 for patients smoking more than 10 cigarettes per day and by 28.2 for patients treated with anticoagulants. CONCLUSIONS: The indicated risk factors should be considered, but the analysis of the results is not sufficient to create a predictive model.

Evaluation of the primary stability in dental implants placed in low density bone with a new drilling technique, Osseodensification: an in vitro study / Evaluación de la estabilidad primaria en implantes dentales colocados en baja densidad hueso con una nueva técnica de perforación, Osteodensificación: un estudio in vitro

Background: Primary stability is an important key determinant of implant osseointegration. We investigated ap-proaches to improve primary implant stability using a new drilling technique termed osseodensification (OD),which was compared with the conventional under-drilling (UD) method utilized for low-density bones.Material and Methods: We placed 55 conical internal connection implants in each group, in 30 low-density sec-tions of pig tibia. The implants were placed using twist drill bits in both groups; groups Under Drilling (UD)and Osseodensification (OD) included bone sections subjected to conventional UD and OD drilling, respectively.Before placing the implants, we randomized the bone sections that were to receive these implants to avoid samplebias. We evaluated various primary stability parameters, such as implant insertion torque and resonance fre-quency analysis (RFA) measurements.Results: The results showed that compared with implants placed using the UD technique, those placed using theOD technique were associated with significantly higher primary stability. The mean insertion torque of the im-plants was 8.87±6.17 Ncm in group 1 (UD) and 21.72±17.14 Ncm in group 2 (OD). The mean RFA was 65.16±7.45ISQ in group 1 (UD) and 69.75±6.79 ISQ in group 2 (OD).Conclusions: The implant insertion torque and RFA values were significantly higher in OD group than in UD.Therefore, compared with UD, OD improves primary stability in low-density bones (based on torque and RFAmeasurements).(AU)

Differences in the shape and direction-course of the nasopalatine canal among dentate, partially edentulous and completely edentulous subjects.

We aimed to analyze the nasopalatine canal shape and anatomical variations of the buccal bone wall and compare the effect of the presence or absence of the central maxillary incisors on the nasopalatine canal. The shape of the nasopalatine canal and the dimensions of the buccal bone wall were measured in 150 patients who underwent a cone-beam computed tomography study. We found that the most prevalent shape of the nasopalatine canal was funnel (31%) and the most common direction-course was slanted-straight (33%). The buccal bone wall in relation to the nasopalatine canal was thickest at the anterior nasal spine level and narrowest at the level of the most anterior-inferior point of the buccal cortex of the maxilla. A statistically significant difference was detected between morphology and direction-course of the nasopalatine canal and dental status. In sum, the study of the nasopalatine canal showed multiple variations. Precise knowledge of these variations may help to decrease the incidence of complications during implantology treatment and during facial and dental surgery.

Gonial angle growth patterns according to age and gender.

Currently there are controversial results about gender and age differences in human gonial angle values. In this context we aimed to ascertain the gender and age differences in the gonial angle values of young Caucasian Mediterranean subjects. We tested the hypothesis of a relation between the gonial angle values and the gender and age of the subjects by means of a prospective study involving 266 subjects. Panoramic radiographs (Cranex Novus®, XMIND Novus® Soredex, France) were carried out in order to measure the gonial angle values. We found significant differences between females and males in the subgroups aged ≤10years old (128.6±3.4 vs 126.8±4.5, p=0.017), 16-20 years old (119.1±5.6 vs 122.3±7.7, p=0.011), 21-25 years old (117.6±5.2 vs 120.8±7.0, p=0.016) and 26-30 years old (117.5±5.4 vs 120.6±5.4, p=0.019) but not in the subgroup aged 11-15 years old (123.4±5.2 vs 123.5±5.4, p=0.927). A significant negative correlation was found between age and gonial angle values (r=-0.365, p<0.001). In sum, females under 10 years of age have significantly higher values than males. The angle values decreased until the age of 11-15 years of age when there were no significant gender differences. Thus, the males aged over 16 years old presented significantly higher values than the females. The decrease in gonial angle values seems to slow or stop from 21 years onwards. Knowledge of the pattern differences will serve for age and gender determination when analyzing human remains.

Radiographic signs associated with inferior alveolar nerve damage following lower third molar extraction

The aim was to carry out a literature review of preoperative radiographic signs in orthopantomography (OPG) and computed tomography (CT) related with the risk of inferior alveolar nerve damage during the surgical extraction of lower third molar (LTM). A search was made on Pub Med for literature published between the years 2000 and 2009.In the reviewed literature, radiographic signs in the OPG that indicate a relationship between the LTM and the inferior alveolar canal are considered a risk factor for nerve damage. These signs are darkening and deflection ofthe root, and diversion and interruption in the white line of the canal. In the majority of these studies, the routineuse of CT is not justified, and is only recommended when radiographic signs appear in the OPG that demonstrate a direct anatomical relationship between the LTM and the canal. In the CT, the absence of cortical bone in the canal implies a contact between the root of the LTM and the canal, and is related with the presence of some radiographic signs in the OPG. Some studies demonstrate that despite the absence of cortical bone, the risk of lesion or exposure of the nerve during the extraction of LTM was low (AU)

No disponible

Distal probing depth and attachment level of lower second molars following surgical extraction of lower third molars: A literature review

A review of the literature is made to evaluate factors that influence probing depth and attachment level on the distal aspect of the lower second molar (L2M) following extraction of a lower third molar (L3M).The PubMed database was searched for studies published between 1997 and March 2009 using the following keywords: mandibular third molar, distal periodontal defect, distal probing depth, distal attachment level, flapdesign. Randomized prospective studies, with a minimum follow-up of three months for which the full text couldbe obtained, and that indicated the attachment level and/or probing depth on the distal surface of the L2M in boththe preoperative and postoperative periods were included.In the studies obtained, flap design had no influence on distal probing depth or distal attachment level of the L2M following extraction of an L3M. Curettage of the distal radicular surface of the L2M, together with oral hygiene control by the dentist, reduced probing depth values. Various authors recommend bone regeneration techniques in patients with a distal periodontal defect prior to extraction. The placing of membranes (resorbable or non resorbable)is not justified; however, the use of demineralized bone powder or platelet-rich plasma gel reduces the distal probing depth and attachment level of the L2M (AU)

No disponible

Radiographic signs associated with inferior alveolar nerve damage following lower third molar extraction.

The aim was to carry out a literature review of preoperative radiographic signs in orthopantomography (OPG) and computed tomography (CT) related with the risk of inferior alveolar nerve damage during the surgical extraction of lower third molar (LTM). A search was made on PubMed for literature published between the years 2000 and 2009. In the reviewed literature, radiographic signs in the OPG that indicate a relationship between the LTM and the inferior alveolar canal are considered a risk factor for nerve damage. These signs are darkening and deflection of the root, and diversion and interruption in the white line of the canal. In the majority of these studies, the routine use of CT is not justified, and is only recommended when radiographic signs appear in the OPG that demonstrate a direct anatomical relationship between the LTM and the canal. In the CT, the absence of cortical bone in the canal implies a contact between the root of the LTM and the canal, and is related with the presence of some radiographic signs in the OPG. Some studies demonstrate that despite the absence of cortical bone, the risk of lesion or exposure of the nerve during the extraction of LTM was low.

Distal probing depth and attachment level of lower second molars following surgical extraction of lower third molars: a literature review.

A review of the literature is made to evaluate factors that influence probing depth and attachment level on the distal aspect of the lower second molar (L2M) following extraction of a lower third molar (L3M). The PubMed database was searched for studies published between 1997 and March 2009 using the following keywords: mandibular third molar, distal periodontal defect, distal probing depth, distal attachment level, flap design. Randomized prospective studies, with a minimum follow-up of three months for which the full text could be obtained, and that indicated the attachment level and/or probing depth on the distal surface of the L2M in both the preoperative and postoperative periods were included. In the studies obtained, flap design had no influence on distal probing depth or distal attachment level of the L2M following extraction of an L3M. Curettage of the distal radicular surface of the L2M, together with oral hygiene control by the dentist, reduced probing depth values. Various authors recommend bone regeneration techniques in patients with a distal periodontal defect prior to extraction. The placing of membranes (resorbable or nonresorbable) is not justified; however, the use of demineralized bone powder or platelet-rich plasma gel reduces the distal probing depth and attachment level of the L2M.

Oral rehabilitation with bone graft and simultaneous dental implants in a patient with epidermolysis bullosa: a clinical case report.

Epidermolysis bullosa (EB) represents a group of mainly hereditary skin disorders, manifested by an exceptional tendency of the skin and mucosa to form bullae and vesicles after minor friction and trauma. Oral features include repeated blistering, scar formation, elimination of buccal and vestibular sulci, and alveolar bone resorption. The use of endosseous implants in the fixed prosthetic rehabilitation of patients with recessive dystrophic EB might provide a considerably better outcome than conventional removable prosthetic methods. This clinical report describes the fixed rehabilitation with 2 implants placed simultaneously with bone graft in a partially edentulous patient diagnosed with recessive dystrophic EB. The implants, with simultaneous bone graft, were placed to decrease the number of surgical operations required, avoiding soft tissue ulcerations and discomfort in the patient. This treatment option appears to be favorable for recessive dystrophic EB patients compared with other options involving removable prostheses, which irritate the oral mucosa.