Digital evaluation of the reproducibility of implant scanbody fit—an in vitro study

Dental restorations are increasingly manufactured by CAD/CAM systems. Currently, there are two alternatives for digitizing dental implants: direct intra-oral data capturing or indirect from a master cast, both with transfer caps (scanbodies). The aim of this study was the evaluation of the fit of the scanbodies and their ability of reposition. At the site of the first molars and canines, implants were placed bilaterally in a polymer lower arch model (original model), and an impression was taken for fabricating a stone cast (stone model). Ten white-light scans were obtained from the original and the stone model with the scanbodies in place. The scanbodies were retrieved after each scan and re-attached to the same implant or lab analogue. The first scan of the series served as control in both groups. The subsequent nine scans and control were superimposed using inspection software to identify the discrepancies of the four scanbodies in both experimental groups. The systematic error of digitizing the models was 13 μm for the polymer and 5 μm for the stone model. The mean discrepancy of the scanbodies was 39 μm (±58 μm) on the original implants versus 11 μm (±17 μm) on the lab analogues. The difference in scanbody discrepancy between original implants and lab analogues was statistically significant (p < 0.05, Mann-Whitney U test). Scanbody discrepancy was higher on original implants than on lab analogues. Fit and reproducibility of the scanbodies on original implants should be improved to achieve higher accuracy of implant-supported CAD/CAM fabricated restorations.     

Influence of patient age and experience of the surgeon on early complications after surgical closure of the cleft palate – A retrospective cohort study

Comparative studies on timing of palatoplasty are rare. The aim of this retrospective cohort study was to compare the influence of early (<14 months) and later (>14 months) one-step closure of the soft and hard palate on early complications.All non-syndromic patients from 1999 to 2009 were included; 6–14 months n = 41 and 15–24 months n = 53. Each palatoplasty was performed as a single-step procedure using bipedicled flaps by a team of two Maxillofacial Surgeons either supervising or operating. The surgeon was rated as “non-experienced” when having performed less than 10 palatoplasties under supervision. Main outcome variable is the occurrence of residual fistula. Fistula occurred in four (4.5%) of the patients. In the multivariate model with respect to the occurrence of fistula neither age, leucocyte count, duration of surgery, nor experience of the surgeon showed a significant influence on the occurrence of a fistula. Only reduced weight contributed to a significantly higher risk of post-operative fistula.In conclusion patient age, experience of surgeon, and duration of surgery had no influence on the early outcome. High leucocyte count had a tendency for and reduced weight had a significant influence on fistula occurrence. Long-term outcome on speech development and maxillary growth have to be collected.     

Comparison of 3D plate and locking plate in treatment of mandibular fracture—a clinical study

Introduction

This study was performed to evaluate the efficacy and post-operative complication of 3-dimensional (3D) titanium miniplate and locking plate in mandibular fractures (parasymphysis, symphysis, body, and angle).

Materials and methods

Forty patients, with non-comminuted mandibular fractures treated with open reduction and internal fixation using 3D titanium miniplate system or locking plate system through an intra-oral approach, were included in this study. All patients were systematically monitored up to 2 months post-operatively. Parameters recorded were infection, occlusal discrepancies, hardware failure, wound dehiscence, sensory disturbance of the inferior alveolar nerve, and stability of fractured segments.

Results

Forty patients with mandibular fracture were divided into two groups randomly without any bias. The fractures of all 40 patients were found to be adequately fixed when checked intra-operatively after fixation. One patient (2.5%) of the 3D plate group developed an infection on the first and second post-operative visit and was treated by antibiotic coverage. One patient in the locking plate group (2.5%) reported wound dehiscence after the first week follow-up.

Conclusion

Both 3D titanium miniplates and locking plate are effective in the treatment of mandibular fractures, and overall complication rates are lesser. However, the 3D plating system uses less hardware in cases of parasymphysis and symphysis fractures and more hardware in cases of body and angle fractures.

     

Influence of the site of origin on the outcome of squamous cell carcinoma of the maxilla—oral versus sinus

The maxilla may be affected by squamous cell carcinoma (SCC) from both oral and sinus sites. We sought to determine whether the site of origin of the maxillary tumour, oral as compared to sinus, influences survival. Univariate Kaplan–Meier and multivariate Cox proportional hazard models analysis of 58 patients with SCC involving the maxilla, treated with curative intent, was conducted. The overall 5-year disease-free survival for the group was 41.7%. Five-year disease-free survival for oral subsite SCC was 56.8%, while for sinus subsite was only 21.6%. Univariate analysis found SCC of sinus origin to be associated with a poorer prognosis, however this was not confirmed on multivariate analysis. T-stage and positive margins were found to be the only independent risk factors. For SCC of the maxilla, sinus origin of the tumour per se does not confer a poorer prognosis; however, as a result of the complex anatomy of the midface, these tumours can present at an advanced stage, while surgical control of the disease can be more difficult, especially posteriorly. Tumour size and positive margins were the determinants of a poor prognosis in this group of patients with maxillary SCC.     

Influence of tongue position on the determination of tooth shade

Statement of problem

Dentists frequently use electronic devices to determine tooth color. However, neither the instructions for these devices nor the accompanying brochures refer to the environmental conditions required at the point of measurement.

A study on the effect on surface detail reproduction of alginate impressions disinfected with sodium hypochlorite and ultraviolet light — An In Vitro study

Objectives of the study

To evaluate the surface detail reproduction of dental casts with impressions made using commercially available alginate impression materials after disinfecting with chemical disinfectant sodium hypochlorite and physical means of disinfection using ultraviolet radiation.

Materials and methods

A stainless steel die was used to make impression according to ADA/ANSI specification No. 18 having 25, 50 and 75 µm lines. Totally 70 impressions were made and divided in to 7 groups. The impressions in the first group were only rinsed with 250 ml of water. The 2nd, 3rd and 4th groups were disinfected by immersing in sodium hypochlorite for 1, 5 and 10 minutes, respectively. Fifth, 6th and 7th group samples were disinfected by placing them in ultraviolet chamber for 6, 12 and 18 minutes, respectively. All the impressions were poured immediately using type III gypsum. The casts were recovered and subjected for evaluation of the 75 µm lines using stereomicroscope.

Results

There was no statistically significant change in the surface detail reproduction when disinfected with sodium hypochlorite or ultraviolet radiation.

Conclusion

Alginate impressions subjected to immersion disinfection using sodium hypochlorite for 1, 5 and 10 minutes and subjected to ultraviolet disinfection for 6, 12 and 18 minutes exhibited no statistically significant differences for surface detail reproduction compared to control groups.     

Assessing the influence of chin prominence on profile esthetics: A survey study

Purpose

The aim of this survey study was to assess the influence of chin prominence on the perception of profile esthetics between genders by orthodontists, oral and maxillofacial surgeons (OMF), plastic surgeons, orthognathic patients and laypersons.

Effect of different remineralizing agents on the initial carious lesions – A comparative study

ObjectivesThis study aimed to assess and compare the effectiveness of three different remineralizing agents (Tricalcium phosphate paste, Fluoride varnish, and Nano-hydroxyapatite gel) using the DIAGNOdent device.Material and MethodsThe present clinical study was carried out on 90 initial carious lesions detected by ICDAS caries diagnostic criteria and then take the baseline record by DIAGNOdent device. The selected initial carious lesions were randomly classified into three groups according to treatment modalities (30 lesions in each group) according to remineralizing agents: group A (TCP), group B (fluoride varnish) and group C (nano-hydroxyapatite gel). The remineralizing agents were applied for four minutes once weekly for four weeks. At the fifth week, the DIAGNOdent scores of initial carious lesions were recorded to evaluate the effect of remineralizing agents. A paired t-test was used to compare between baseline date and follow up of DIAGNOdent scores. A one-way ANOVA test was used to compare DIAGNOdent scores among the three groups. Post- Hoc Tukey test was used to determine the significant difference between every two groups.ResultsThere were statistically significant differences among the three groups at follow up (p = 0.001). Within each group, there was a significant difference between baseline and follow up scores (p = 0.000 for the three groups). Multiple comparisons between every two groups showed a highly statistically significant difference at follow up records between nano-hydroxyapatite versus TCP and fluoride varnish on pit and fissure caries (p = 0.039 and p = 0.007 respectively) and the nano-hydroxyapatite was the best of them.ConclusionThe present study concluded that the three remineralizing agents were effective in the treatment of initial carious lesion and the most effective remineralizing agent was nano-hydroxyapatite.     

Isotretinoin effect on the repair of bone defects – A study in rat calvaria

BackgroundIsotretinoin is a vitamin A derivative, indicated for the treatment of patients with severe acne, which shows several side effects on bone metabolism.ObjectiveThis study analyzed the process of bone repair in rats receiving 7.5 mg/kg/day of oral isotretinoin.MethodsThirty-three male albino Wistar rats, at approximately 60 days of age, were randomly assigned to control (n = 15) and experimental (n = 18) groups. Only the experimental group underwent oral isotretinoin therapy. In both groups, a 2-mm cavity was established in the calvarium of each animal. The animals were euthanize 21, 28 and 90 days postoperatively. The parietal bone was removed and the surgical specimens underwent histological examination. Computed histomorphometry allowed the measurement of the total area of bone defects and the proportion of newly formed bone at the different observation time points.ResultsIn the experimental group, the results, expressed as mean percentage of newly formed bone, were: 25.37% (±9.14) at day 21; 41.78% (±7.00) at day 28; and 57.51% (±11.62) at day 90. In the control group, the results were: 17.10% (±9.23) at day 21; 34.42% (±7.70) at day 28; and 48.49% (±16.40) at day 90.ConclusionThese results enabled us to conclude that isotretinoin promoted acceleration in the process of new bone formation in rat calvaria, although this increase was not statistically significant.     

The role of diabetes mellitus on the formation of severe odontogenic abscesses—a retrospective study

Objectives

To analyze the correlation of diabetes mellitus and hyperglycemia with severe odontogenic abscesses.

Materials and methods

Records of all patients in the Department of Oral and Maxillofacial Surgery of the Medical Center of the Johannes Gutenberg-University who underwent inpatient treatment for severe odontogenic abscesses between 2010 and 2016 were evaluated retrospectively regarding diabetes anamnesis, maximum and fasting blood sugar count, and duration until discharge. In order to compare the numbers to a general maxillofacial group, all patients who received inpatient treatment in 2013 for any diagnosis other than an abscess of the head and neck region were analyzed as well, and the numbers were correlated.

Results

In total, 977 abscess patients were found in the analyzed period. 7.0% of the patients had a known diagnosis of diabetes mellitus type II and 0.6% of type I. Correlation with the general group showed that abscesses were significantly more likely in diabetics as well as patients with abnormal maximum and fasting blood sugar counts. These patients also needed significantly longer inpatient treatment.

Conclusions

Diabetics and patients with abnormal glucose tolerance show significantly higher numbers of severe odontogenic abscesses and might therefore benefit from earlier escalation of antibiotic medication.

Clinical relevance

Severe odontogenic abscesses are one of the most frequent diagnoses in maxillofacial practice. Adjusting the therapeutic approach for diabetics or patients with abnormal blood sugar counts might help to prevent the development of abscesses.

     

The Influence of Adalimumab on the Healing of Apical Periodontitis in Ferrets

Introduction

Given the increasing use of anti–tumor necrosis factor α (anti-TNFα) biologic medications, and their interferences with the immune-inflammatory response, this study evaluated the effect of adalimumab (anti-TNFα), on healing and healing time of apical periodontitis (AP) in ferrets.

Effects of anterior tooth crown inclination on occlusal relationship—A study in three-dimensional reconstruction

ObjectiveThis study aims to analyze the relationship between the central incisor crown inclination and occlusal relationship via three-dimensional study.MethodsTen Chinese volunteers with normal occlusion were selected from physical examination of college students. Lateral cephalograms and CT scans were taken, and the CT data were imported into Simplant pro 11.04 to reconstruct three-dimensional model. In the three-dimensional model, every tooth was separated independently. The upper and lower central incisors were moved labial inclination(up) or lingual inclination(down) and then the upper and lower tooth were aligned based on the central incisor’s position according to the principles of Andrew’s six keys. Four groups were set up with different changes of central incisors. The upper and the lower arch were aligned again based on the moved central incisors. After every motion, the mesio-distal distances of upper and lower canines and first molars were recorded. All data were analyzed using t-test via SPSS19.0, and the significance level was set at 5%.ResultsThe results showed that the mesio-distal distances of occlusal relationship were different from normal occlusal relations, when either upper incisor crown inclination or lower incisor crown inclination was changed, and both upper and lower incisor crown inclination were moved in same or opposite direction. According to the statistical analysis, there was no significant difference when the changes of U1-L1 were no more than 10° (P > 0.05). But there was statistically significant difference (P < 0.05) when changes of U1-L1 were more than 20°.ConclusionsThe incisor crown inclination has influence on the establishment of occlusal relationships. The bigger difference upper and lower incisor crown inclination has, the more deviations from the normal occlusal relationship exist.     

Impact of depressive symptoms on prosthetic status—results of the study of health in Pomerania (SHIP)

Objectives

Previous investigations have confirmed that every fifth dental patient suffers from clinically significant depressive symptoms. However, the putative impact of depressive symptoms on the prosthetic status has not been addressed in these studies. The objective of this study was to investigate the association between depressive symptoms and prosthetic status based on data from the Study of Health in Pomerania (SHIP-0).

Methods

Data from 2,135 participants aged 30 to 59 years were analyzed. A classification (six classes regarding the number and position of missing teeth per jaw) was used to identify the degree of prosthetic status (no/suboptimal/optimal tooth replacement). The presence of depressive symptoms was assessed with a modified version of von Zerssen’s complaints scale. Screening for lifetime diagnoses of mental disorders was performed with the Composite International Diagnostic-Screener (CID-S). Multivariable logistic regressions including several confounders were calculated.

Results

A significant protective dose–response effect of depressive symptoms on prosthetic status was found only in men for the lower jaw [0–1 depressive symptoms: odds ratio (OR)?=?3.84, 95 % confidence interval (CI, 1.65–8.92), p?<?0.01; 2–3: OR?=?2.87 (CI, 1.22–6.74), p?<?0.05; reference, ≥8; adjusted for age, school education, smoking status, household income, marital status, living without a partner, risky alcohol consumption, obesity, diabetes, and physical activity]. There was no such association in women or for the upper jaw. The analyses using the CID-S confirmed these results.

Conclusions

In the lower jaw, men with depressive symptoms had a better prosthetic status than men without depressive symptoms suggesting a higher level of concern regarding their personal health.

Clinical relevance

If dentists might have an opportunity to identify men with depressive symptoms they can provide a wide range of treatment options that may enhance patients’ self-esteem and contribute to the patient’ well-being. Furthermore, depressive symptoms could indicate a discrepancy between self-perception of the dental health and the actual status which influence the dentists’ treatment decision making.     

Comparative evaluation of 2.0-mm locking plate system vs. 2.0-mm nonlocking plate system for mandibular fractures — a retrospective study

Introduction

The purpose of this retrospective study is to evaluate the efficacy of the 2.0-mm locking miniplate/screw system in comparison to the 2.0-mm nonlocking miniplate/screw system in mirror image mandibular fractures.

Material and method

A retrospective clinical trial was reviewed in the Department of Oral and Maxillofacial Surgery, Government Dental College, Pt. B.D. Sharma University of Health Sciences Rohtak for a period of 30 months (June 2007 to December 2009). A total of 30 patient pairs with isolated identical mandibular fracture (single or multiple) having 88 fractures were analyzed.

Results

A total of 11 complications that occurred represented 12.5 % of the total. Six complications occurred at angle, three in the body and two at parasymphysis. Four complications occurred in the locking group and seven in the nonlocking group, with complication rates accounting for 9 % and 16 %, respectively. When comparing the overall complication rates according to plates used, the chi-square test showed no statistically significant difference between the locking and nonlocking plates (p?>?0.05).

Discussion

Mandible fractures treated with the 2.0-mm locking plates and the 2.0-mm nonlocking plates present similar short-term complication rates.