Non-steroidal, anti-inflammatory drugs and statins are two widely prescribed drug classes that affect bone formation. The aim of this study was to elucidate the effect of diclofenac and simvastatin in artificial bone defect healing. One hundred and forty-four male Wistar rats were used, and the specimens were divided into groups, with respect to the route of drug administration and the type of defect healing (with or without collagen membrane), and subgroups, with respect to the study duration (2, 4 or 8 weeks). Diclofenac was intramuscularly administered while simvastatin was administered both systemically and locally. Animals were euthanized and specimens were histomorphometrically analyzed to evaluate the percentage of new bone formation (%). Bone healing that occurred without any intervention developed more steadily than that of all other groups. Diclofenac exerted a clear, direct inhibitory effect on bone healing and its systemic administration should be avoided. The systemic administration of simvastatin was related to severe myopathy, while the solvent for the local administration of simvastatin seemed to play significant role in bone growth, as simvastatin, when it is administered intraperitoneally in a DMSO solution, appeared to promote bone healing. Local administration may have a significant impact on bone healing and it should be further investigated with the type of solvent or carrier that is used, which both may play a significant role in bone repair induction.

Summary Objective To investigate the effects of orthodontic forced eruption (OFE) with the straight-wire appliance in the dimensions of the alveolar process when used for extracting compromised maxillary anterior teeth and implant site development. Material and Methods Cone-beam computed tomography (CBCT) scans of 7 patients needing extraction of 17 maxillary anterior teeth were obtained before and immediately after OFE. Alveolar plate height and thickness measurements were performed on the buccal and palatal socket walls in CBCT sagittal cross sections. Statistical analysis included sample size calculation, paired t-test, and Wilcoxon test to evaluate alveolar plate dimensional changes and linear regression analysis to assess whether bone changes and the feasibility of implant insertion were associated to tooth type and root length, baseline alveolar plate thickness, and age. Results OFE caused statistically significant reduction of the buccal alveolar plate height (1.95 ± 1.83 mm) and significant increase of the palatal alveolar plate height (1.31 ± 2.41 mm) in the central tooth socket areas. Buccal reduction was associated positively to the baseline root length and negatively to the thickness of the corresponding plate in the apical level. A non-significant increase was noted in both buccal (0.23 ± 0.93 mm) and palatal (0.63 ± 1.59 mm) proximal bone. Inadequate buccal bone support hindered immediate implant placement in six sockets; however, all inserted implants showed adequate and gradually increasing stability from insertion to final restoration. Conclusions OFE resulted in favourable increase in the heights of the palatal and proximal alveolar bone and significant reduction in the buccal plate height, which inhibited implant placement in 35% of the treated sockets.

Dataset for all analyses done in the study

BACKGROUND:Clopidogrel is a widely prescribed drug for prevention of myocardial infarction and stroke in patients at risk. It inhibits thrombus formation via inhibition of the P2Y12 purinergic receptor on platelets, which is important in their activation by ADP. However, the P2Y12 receptor has also been found to be expressed in both osteoblasts and osteoclasts. Accumulated evidence suggests that purinergic receptors regulate important functions of bone turnover. Previous studies on the effect of clopidogrel on bone metabolism indicated potential harmful effects, but their results remain conflicting. Thus, clopidogrel treatment may affect bone healing, but it has not yet been studied. AIM:To evaluate if continuous perioperative clopidogrel treatment has any negative effect on bone healing in the rabbit calvarial defect model. METHODS:Sixteen male white New Zealand rabbits were randomly assigned in two groups: One group received daily 3 mg/kg of clopidogrel per os and the other group received the vehicle alone for a week prior to the surgical procedures; the treatments were continued for another 6 wk postoperatively. The surgical procedures included generation of two circular calvarial defects 11 mm in diameter in every animal. After the 6-wk period of healing, postmortem radiographic and histomorphometric evaluation of the defects was performed. RESULTS:Both the surgical procedures and the postoperative period were uneventful and well tolerated by all the animals, without any surgical wound dehiscence, signs of infection or other complication. New bone was formed either inwards from the defect margins or in the central portion of the defect as separated bony islets. While defect healing was still incomplete in both groups, the clopidogrel group had significantly improved radiographic healing scores. Moreover, the histomorphometric analysis showed that bone regeneration (%) was 28.07 ± 7.7 for the clopidogrel group and 19.47 ± 4.9 for the control group, showing a statistically significant difference between them (P = 0.018). Statistically significant difference was also found in the defect bridging (%), i.e. 72.17 ± 21.2 for the clopidogrel group and 41.17 ± 8.5 for the control group, respectively (P = 0.004), whereas there was no statistical difference in bone tissue density between the groups. CONCLUSION:Our results indicate that maintenance of perioperative clopidogrel treatment does not negatively affect bone healing but rather promotes it. Further research is needed in order to find useful applications of this finding.

The population of patients eligible for chronic antiplatelet treatment is expanding globally, in tandem with the rising prevalence of cardiovascular disease and the increasing use of percutaneous coronary interventions. While antiplatelet agents have revolutionized the management of atherosclerotic disease and its thrombotic complications, the potential of bleeding remains an inherent risk. Temporary withdrawal of antiplatelet therapy may therefore seem an attractive option in iatrogenic settings that pose a bleeding hazard; in this case, however, the benefit of averting antiplatelet-induced hemorrhage needs to be balanced against the risk of potentially fatal thrombosis, particularly in the expanding cohort of patients with drug-eluting stents (DES). Dental extractions represent the most frequent minor surgical procedures in the general population, yet the optimal dental management of antiplatelet-receiving patients is insufficiently explored. Sporadic cases of postextraction bleeding have been reported in the setting of continuous aspirin therapy, but reports of serious or life-threatening hemorrhage are extremely rare. Very few studies have systematically assessed the effect of aspirin or clopidogrel on the procedural outcome of dental treatment; these studies generally focused on the safety of dental procedures in the setting of uninterrupted antiplatelet monotherapy. The safety of dual antiplatelet therapy has been studied to an even lesser extent, and even these studies were limited by their retrospective design and by the small and heterogeneous patient populations. In the most comprehensive relevant report, Napenas et al included 29 patients receiving dual antiplatelet treatment and found a very low frequency of prolonged postextraction bleeding; however, the heterogeneity of the invasive procedures and the absence of a group of antiplatelet-naive controls limited the interpretation of their results. In light of the paucity of relevant studies, and particularly the absence of prospective investigations, defining a strategy to optimally balance the bleeding risk of uninterrupted antiplatelet therapy versus the thrombotic hazard of temporary antiplatelet withdrawal before dental procedures has been an unanswered question for a frequent clinical problem. Current recommendations suggest uninterrupted antiplatelet therapy in patients with DES undergoing dental procedures. In striking contrast to these recommendations, however, antiplatelet agents are frequently interrupted in everyday practice. This is clearly an empirical, rather than an evidence-based approach, based on excessive concerns about potential postextraction bleeding complications. Aiming to address this gap of evidence-based practice, the safety of dental extractions during uninterrupted single or dual antiplatelet treatment was recently assessed in a prospective fashion. In a study published in the American Journal of Cardiology, we included 643 patients referred for dental extractions. Of them, 42 (6.5%) were on clinically indicated daily low-dose aspirin, 36 (5.6%) were on clopidogrel, 33 (5.1%) were on both aspirin and clopidogrel, while 532 antiplatelet-naive patients served as controls. Treatment groups and controls were well matched clinically and received similar procedural treatment, thereby allowing for direct

OBJECTIVES:The aim of the present study was to investigate the prevalence of impacted and supernumerary teeth, apart from third molars.STUDY DESIGN:This was a retrospective study of 1.239 panoramic radiographs taken of patients who presented to the Department of Dentoalveolar Surgery, Implantology and Radiology at the School of Dentistry of the Aristotle University of Thessaloniki, Greece between 1991 and 1999. The panoramic radiographs and dental records were reviewed in order to determine whether there were impacted or supernumerary teeth. Observations were also made on the space in dentition, corresponding to the position of each impacted tooth, the lack of space for tooth eruption, transmigration, retained primary teeth or prosthetic restoration.RESULTS:A total of 170 (13.7%) patients presented with at least one impacted tooth. None of them had an impacted incisor. Impacted canines were the most prevalent dental anomaly (8.8%), followed by impacted premolars (2.2%). Supernumerary teeth (1.8%) and impacted molars (1%) were the least common anomalies. Among the 225 impacted teeth, the most frequently affected teeth were the canines (59.6%), followed by premolars (19.1%), and supernumerary teeth (15.1%), while the incidence of impacted molars was substantially lower (6.2%).CONCLUSIONS:The most frequently impacted teeth were the maxillary canine, the second mandibular premolar and the second mandibular molar. The majority of the supernumerary teeth consisted of mesiodens. There was space in the dentition of each impacted tooth in 29.3% of the cases examined; there was a retained primary tooth in 25.1%, and a prosthetic restoration had been constructed in 24%. Insufficient space for the eruption of the impacted tooth and transmigration was observed in 17.3% and 4.2% of the cases, respectively.

Optimal dental management in patients on long-term antiplatelet treatment is not clearly defined. Antiplatelet discontinuation increases the risk of thrombotic complications, whereas uninterrupted antiplatelet therapy, which is the currently recommended approach, is assumed to increase the bleeding hazard after dental procedures. We sought to prospectively compare the risk of immediate and late postextraction bleeding in patients receiving uninterrupted single or dual antiplatelet therapy. We recruited 643 consecutive patients referred for dental extractions. In total 111 (17.3%) were on clinically indicated antiplatelet therapy: aspirin (n = 42), clopidogrel (n = 36), and aspirin and clopidogrel (n = 33). Controls (n = 532, 82.7%) were not on antiplatelet treatment. Immediate and late bleeding complications were recorded. Compared to controls the risk of prolonged immediate bleeding was higher in patients on dual antiplatelet therapy (relative risk [RR] 177.3, 95% confidence interval [CI] 43.5 to 722, p <0.001) but not in patients on aspirin alone (RR = 6.3, 95% CI 0.6 to 68.4, p = 0.2) or clopidogrel alone (RR = 7.4, 95% CI 0.7 to 79.5, p = 0.18); however, all immediate bleeding complications in all treatment groups were successfully managed with local hemostatic measures. No patient developed any late hemorrhage. In conclusion, dental extractions may be safely performed in patients receiving single or dual antiplatelet therapy when appropriate local hemostatic measures are taken, thus averting thrombotic risk of temporary antiplatelet discontinuation.

Needleless devices have been developed to provide anesthesia without injections. Little controlled research has examined the acceptability of needleless devices in pediatric patients. The aims of the study were to compare children's acceptance and preference for one type of needleless jet injection with classical local infiltration as well as to evaluate the efficacy of the needleless anesthesia. Eighty-seven nonfearful children with no previous experience of dental anesthesia were studied using a split-mouth design. The first dental procedure was performed with the classical infiltration anesthesia. The same amount of anesthetic was administered using the INJEX needleless device in a second session 1 week later, during which a second dental procedure was performed. Patients rated their acceptance and preference for the 2 methods, and the dentist recorded data about the need for additional anesthesia. More negative experiences were reported for the INJEX method. Most (73.6%) of the children preferred the traditional method. Among the 87 treatment procedures attempted following the use of INJEX, 80.5% required additional anesthesia, compared with 2.3% of those attempted following traditional infiltration. Traditional infiltration was more effective, acceptable, and preferred, compared with the needleless INJEX.

AIMTo compare digital panoramic images acquired for the presurgical assessment of third molars captured with a storage phosphor-based system with conventional film panoramic radiographs.METHODS AND MATERIALSA total of 51 pairs of digital and conventional panoramic images, made simultaneously, were included in this study. The images were evaluated for diagnostic quality prior to third molar surgery by two experienced oral surgeons and rated with a four-point grading scale.RESULTSDespite the fact that conventional panoramic images were rated higher than the digital images, the difference was not statistically significant.CONCLUSIONSConventional and digital panoramic images were found to be of comparable image quality with regard to their diagnostic contribution to third molar surgery.CLINICAL SIGNIFICANCEThis study is contributory to understanding differences in image quality between digital and conventional panoramic radiography for certain diagnostic tasks. The lack of significant differences in image quality may be an endorsement for digital panoramic radiography.

PURPOSE:The influence of bone marrow in the osteogenic potential of bone has not been evaluated in the rabbit tibia model. Previous studies employed this model extensively to test the osteogenic capabilities of bone grafts. The primary aim of the present study was to assess the role of bone marrow in the healing of experimental defects in the rabbit tibia model.MATERIALS AND METHODS:Ten New Zealand rabbits were divided into two groups of five each. In the first experimental test group (PoP), the marrow cavity was emptied completely under a 6-mm defect in the rabbit tibia metaphysis; the marrow was replaced by plaster of Paris, and a round piece of lyophilized collagen membrane was placed in contact with the endosteum and rested on the plaster. In the second experimental group (control), similar artificial defects were made, but the marrow was left intact. After 8 weeks, the animals were sacrificed and prepared for histologic and histomorphometric analysis.RESULTS:There was a statistically significant difference (P = .016) in newly formed bone area between the control group (mean, 68.08% +/- 12.09%) and the PoP group (mean, 54.02% +/- 13.93%). Similarly, there was a statistically significant difference in new bone density (P < .001) between the control group (mean, 95.99% +/- 1.74%) and the PoP group (mean, 75.37% +/- 13.27%).CONCLUSIONS:The current study confirms the significant effect that bone marrow has in bone regeneration and also the true regenerative capabilities of the osseous walls of the defects. The proposed experimental model may be a more reliable method of investigating and comparing the potential of different graft materials and methods.

The purpose of this study was to evaluate crestal bone loss around 282 two-piece implants with straight (n = 193) and platform-switched (n = 89) abutment connections after placement at various crestal levels. Implants were assigned into two groups according to straight and platform-switched abutment connections. Each group was further subdivided into three groups depending on the location (supracrestal, crestal, or subcrestal) of the implant cervical platform. Linear measurements of bone resorption were made from the implant's platform to the first point of bone-to-implant contact at the time of implant placement and 2 years postrestoration. Data were statistically analyzed. Statistically significant differences were found between subgroups in both straight and platform-switched categories. The only nonstatistically significant difference (P = .341) arose when comparing the supra- and subcrestal locations in the straight abutment connection group. The platform-switched group exhibited significantly less bone loss (P = .046) only in subcrestal locations. The platform-switched concept was not beneficial during the overall comparison, but it was for the subcrestal location of the abutment connection. Crestal placement of the implant-abutment connection resulted in higher marginal bone resorption in both straight and platform-switched abutments.

The role of temperature in the action of local anesthetics was studied in 20 healthy young volunteers with plain 3% mepivacaine injected periapically twice in their maxillary first premolar, the first time with the solution at a temperature of 20 degrees C and the second time at 4 degrees C. The pulpal response was measured with a pulp tester every minute. The onset of pulp anesthesia was found to be of no statistical difference between 20 degrees C and 4 degrees C. On the other hand, mepivacaine at a temperature of 4 degrees C was found to have a statistically significant longer duration of action. Our conclusion is that the drop in temperature of mepivacaine from 20 degrees C to 4 degrees C provides a longer duration of pulpal anesthesia.

The mandible with the ageing process is susceptible to alterations in terms of its shape and size. At the old age, after the collapse of teeth, the alveolar process is absorbed and, as a result of this, the mandibular canal and the mental foramen are found to be close to the superior border. The body of the mandible resembles the basic part of the mandible. There is reference to a case with an evident atrophic mandible and exposition of the inferior alveolar neurovascular bundle on an 81- year-old male cadaver who carried a complete denture in the mandible. The above case is also remarked on a 70- year- old- male patient who could not bear the denture for ten years. The patient rehabilitated with an implant-overdenture retained on two endosseous osseointegrated implants. The final result was functionally and esthetically a success. The exposition of the inferior alveolar neurovascular bundle in an atrophic mandible is almost rare but it presents anatomical and clinical interest.

Se estudiaron los resultados de 305 extracciones de molares inferiores en 2 grupos de pacientes para determinar si el uso de anestesia intraligamentosa aumenta la incidencia de alveolitis seca. En el primer grupo se aplico un bloqueo nervioso alveolar inferior, en el segundo, anestesia intraligamentosa. Se empleo una solucion de lidocaina al 2% con 1:80.000 de epinefrina. El analisis estadistico de la presentacion postoperatoria de alveolitis seca indico que el uso de anestesia intraligamentosa no producia mayor incidencia de este cuaaro que la anestesia convencional. (Quintessence Int 1992; 23:575-577)