Does the systemic administration of L-arginine affect dental implant stability in nicotine consumer dogs?

Background

Nicotine can have detrimental effects on dental implant osseointegration. This study aimed to evaluate the influence of systemic l-arginine supplement on the osseointegration of dental implants in nicotine consumer dogs.

Methods

Twelve 1-year Labrador Retriever dogs had their right and left third and fourth mandibular premolars removed, and the sockets were left to heal for 6 months. Dogs were randomly divided into three groups (n = 16): group 1—0.2 mg/kg nicotine was injected twice daily; group 2—0.2 mg/kg nicotine was injected twice daily in addition to 200 mg/kg l-arginine capsules taken orally; and group 3—placebo. Forty-eight dental implants were inserted into the healed sockets of the dog’s mandible and were assessed by implant stability quotient (ISQ) using resonance frequency analysis (RFA) during 4 weeks and insertion and removal torque value analysis.

Results

No implant failure occurred during the study period. The change in torque value between insertion and removal was similar in the placebo and nicotine+arginine consumer dogs (p = 0.276), which shows a positive effect of arginine supplementation in nicotine consumers. There was a significant difference in torque value change between nicotine+arginine vs. nicotine consumers (p = 0.049) and placebo vs. nicotine (p = 0.003). After 4 weeks, the placebo had the most significant improvement in torque value (47.0 ± 16.9), followed by nicotine+arginine (25.1 ± 37.8), and the worst torque value was for the nicotine group (− 5.7 ± 24.0) pound per inch. The results show that except in the first week, there are significant differences in ISQ between the groups in different periods. ISQ in all of the groups has reduced at first but then increased over time. At the time of implant placement, insertion torque was significantly higher in the nicotine consumer group than the nicotine+arginine consumer group and placebo group (p = 0.020).

Conclusion

Arginine supplementation promotes bone healing and implant primary stability by improving dental implant osseointegration biomechanical characteristics.

Osteonecrosis of the Jaws in Patient Received Bisphosphonates and Sunitinib Separately: A Case Report

Recently published reports have suggested that antiangiogenic drugs such as sunitinib could potentiate the osteonecrosis of the jaw (ONJ) induced by bisphosphonates (BPs) and even induce this adverse effect per se. We reported a case of ONJ with renal cell carcinoma under sunitinib medication and history of BPs therapy. A 53-year-old man was referred to the oral surgery clinic complaining of painful exposed oral lesion and bone extraction from right lower jaw in the mouth. He underwent nephrectomy followed by 5 months treatment with cycles of 50 mg sunitinib (Sutent^®) once a day for 4 weeks followed by 2 weeks drug free before lesion exposure in October 2016. However, the patient has encounter to intermittent mucositis and gingivitis in oral cavity several times. Our patient had a history of zoledronic acid (4 mg intravenously two times) administration due to primary cancer misdiagnosis. In our case, no dental procedure contributed to the occurrence of ONJ. The lesion was improved by sunitinib cessation and administration of antibiotics through 2 weeks. Mucosal injury induction as well as inhibition of angiogenic signaling pathways by sunitinib administration may have precipitated the occurrence of ONJ. In addition, a possible synergistic effect by previously BP treatment is another accused.

A 7-year study of 1,278 patients with maxillofacial trauma and cerebrospinal fluid leak

BACKGROUND

A number of patients with facial fractures have cerebrospinal fluid (CSF) leak that may result in meningitis and other central nervous system complications. Commonly, CSF leak occurs following trauma, but the etiology and pattern of this disorder are different from region to region. This study aims to evaluate the distribution of CSF leak in patients with maxillofacial fractures in Isfahan province, Iran.

PATIENTS AND METHODS

In this retrospective cross-sectional study, 1,287 medical files of patients admitted to a medical center with head and face injuries were evaluated during a 7-year period (2004-2010). Data was obtained using descriptive analysis.

RESULTS

Of the 1,278 patients with head and maxillofacial fractures, 16 (1.25 %) males and one (0.07 %) female had CSF leak; all these cases had skull base fracture. Of these, 52.9 % had maxillary fracture, 23.5 % nasal fracture, 41.1 % orbital fracture, 11.7 % mandibular fracture, 23.5 % frontal fracture, and 41.1 % had more than one site of fracture. 58.8 % had rhinorrhea and 41.2 % otorrhea. Of all these patients with CSF leak, 8 (47 %), 2 (11.8 %), and 7 (41.2 %) cases were treated spontaneously, using lumbar drain placement, and by surgical intervention, respectively.

CONCLUSIONS

Cerebrospinal fluid leak was observed most frequently in patients with fracture in the zygomatic and maxillary bone, and mostly exhibited itself as rhinorrhea and/or otorrhea. All cases with CSF leak had skull base fracture as well. However, post-traumatic CSF leaks are uncommon and are generally treated without surgical intervention (59 %). Distribution of CSF leak varies from one region to another and knowing this fact helps to manage the injury and prevent the complications.

The relation of pericoronal third molar follicle dimension and bcl-2/ki-67 expression: An immunohistochemical study

Background:

Most common impacted teeth are the mandibular third molars and decision about extraction of them is usually controversial. The presence of pericoronal pathologic changes is an acceptable reason for removal of impacted teeth. Differences in the proliferation rate and apoptosis of odontogenic epithelial cells may influence on the formation of odontogenic epithelial lesions. Therefore, the aim of the present study is to evaluate the immunohistochemical expression of the bcl-2 apoptosis-inhibiting protein and the cell-cycle-related ki-67 antigen in pericoronal follicle of impacted third molars with ≥2.5 mm and <2.5 mm radiolucency.

Materials and Methods:

This was a cross-sectional study that 20 follicles with <2.5 mm radiolucency and 20 follicles with ≥2.5 mm radiolucency were selected by a professional radiologist in digital panoramic radiographs and then referred to a surgeon. Formalin fixed paraffin-embedded tissues were immunohistochemical analyzed for immunoreactivity of bcl-2 protein and ki-67 antigen. The data was analyzed using logistic regression, Spearman correlation coefficient and t-test and Mann-Whitney. P<0.05 was considered significant.

Results:

The findings showed correlation between size of the third molar's follicles and expression of bcl-2 protein (P < 0.001, r = 0.556) but there was no correlation between size of third molar's follicles and staining with ki-67 antigen (P = 0.546, r = 0.098). The follicles with radiolucency ≥2.5 mm showed increased immunoreactivity for bcl-2 protein.

Conclusion:

The results of study suggest that impacted third molars with radiolucency ≥2.5 mm may be associated with deregulation of cell death, indicated with increased expression of the anti- apoptotic protein bcl-2, while cell proliferation (ki-67) does not seem to play a significant role.

Comparative evaluation of two types of immediately loaded implants using biomechanical and histomorphometric tests: an animal case study

Introduction. In order to minimize the required time to regain esthetic and function, immediately loaded implants were suggested. The aim of this study was to comparatively evaluate the Nisastan and XIve implants using biomechanical and histomorphometric tests. Materials and Methods. In this experimental study, 6 Nisastan one-piece immediately loaded screw type implant (OPILS) and 6 Xive implants with 3.4 mm diameter and 11 mm long were used. The implants were immediately loaded with temporary coating. After three months, the torque required to break bone-implant contact was measured and was recorded. All implants were extracted with surrounding bone and histologically were evaluated. The data were inputted into the SPSS 11.5 to run student T-test statistical analyses (α = 0.05). Results. The success rates of both types of implants was 100%, and none of them failed due to mobility or bone loss. The mean removal torque value (RTV) was 142.08 and 40 N/Cm for Xive and Nisastan implants, respectively, and their RTVs showed a significant difference between two mentioned implants (P = 0.004). None of the histomorphometric values showed significant differences between the two implants (P > 0.05). Discussion. both systems have the capability to induce osseointegration under immediate loads but that Xive implants showed higher capability for bone contact.

The association between blood groups and maxillofacial deformities

Background:

Blood group is a genetic characteristic which is associated with some diseases and deformities. Multifactorial characteristics of facial development make it difficult to predict a genetic pattern in a specific maxillofacial deformity, but epidemiological evaluations can reveal relationships between such deformities and some genetic characteristics or accompanied diseases, and this will help to recognise and treat them. The aim of this study is evaluation of the relationship between blood groups and maxillofacial deformities.

Materials and Methods:

In this study, blood groups of 190 patients with maxillofacial deformities who had had orthognathic surgery in Alzahra hospital, Isfahan, were compared with the general Iranian population.

Results:

Among 190 patients, 93 cases (49%) were men and 97 cases (51%) were women. Fifteen cases (8%) were < 20 years old, 130 cases (68%) were 20–30 years old, and the others (45 cases, 24%) were > 30 years old. The blood group distribution in our samples was as follows: blood group O = 76 cases (40%), blood group A = 58 cases (30%), blood group B = 41 cases (22%), and blood group AB = 15 cases (8%). Among these patients, 31 cases (16%) had maxillary deformities and 27 cases (14%) suffered from mandibular deformities while the other 132 cases (70%) had bimaxillary problems. The Chi-square test showed statistically significant differences between the blood group distribution of the patients of this study and the normal Iranian population (P < 0.001).

Conclusion:

It was shown that among different blood groups; those with blood group B have a greater likelihood of association with maxillofacial deformities. On the other hand, the probability of the association of such deformities was the least with blood group A.