Closing anterior open bites by intruding molars with titanium miniplate anchorage

The intent of this study was threefold: (1) to validate true intrusion of molars in adults, (2) to test the stability of miniplates as anchorage for intruding posterior teeth in the maxilla, and (3) to record the skeletal and dental changes of open-bite closure. Four adult patients who had anterior open-bite malocclusions were selected to undergo posterior intrusion with miniplate anchorage to close the open bite; all had true intrusion of the maxillary molars. Mean molar intrusion was 1.99 mm (range, 1.45-3.32 mm). No movement of miniplates occurred at any time during their use or before intentional clinical removal. Open-bite closure was achieved for all 4 patients. Mean closure of incisors was 3.62 mm (range, 3.0-4.5 mm) as the mandibular plane closed 2.62 degrees (range, 1.5 degrees -4.5 degrees ), and the occlusal plane decreased 2.25 degrees (range, 1.0 degrees -3.5 degrees ). Anterior facial heights decreased as the mandible closed and B-point rotated anteriorly and upward.     

Repair of porcelain/metal restoration with resin bonded overcasting.

Porcelain occasionally fractures from ceramometal fixed partial dentures following final cementation. Repair of these porcelain fractures can be a challenging task. When the problem occurs on anterior teeth, it is especially difficult because the repair must not only be durable, but esthetically pleasing as well. Although composite resins can be used for some repairs, it is often difficult to match the color and texture to the surrounding intact porcelain. In addition, the bonding between the resin and porcelain is susceptible to margin leakage, which may ultimately cause an esthetic failure. Techniques involving a cemented porcelain-fused-to-metal overcasting have often been successful in restoring the fixed partial denture to form and function. Although the esthetic result of a porcelain/metal overcasting can be quite successful, retention of the overcasting is sometimes poor. The compromised retention and resistance form is due to lack of interproximal walls on the underlying fractured unit. To improve the retention of the overcasting, the following technique of tin plating the overcasting and fractured unit prior to cementing with a composite resin cement is presented.     

A 30-day clinical comparison of a novel interdental cleaning device and dental floss in the reduction of plaque and gingivitis

OBJECTIVE: To compare the safety and efficacy of a novel battery-operated interdental cleaning device (Oral-B Hummingbird) [ID], fitted with either a flossette or pick attachment, versus hand-held dental floss in the reduction of plaque and gingivitis when combined with manual tooth brushing over a 30-day period. METHODOLOGY: This randomized, examiner blind, parallel group study assessed three treatment groups: ID/flossette (ID/F), ID/pick (ID/P), and unwaxed manual dental floss. All groups used the same soft manual toothbrush and toothpaste. The 84 subjects were stratified to treatment groups based on initial whole mouth mean plaque scores, gingivitis scores, and gender. Subjects were instructed to brush twice daily and use their assigned interdental method once daily in the evening before brushing. Gingivitis, gingival bleeding, and plaque were evaluated at baseline and Day 30. RESULTS: A total of 78 subjects completed all aspects of the study and were included in the analyses. There was no significant difference between treatment groups in baseline plaque, gingivitis, and bleeding scores. After 30 days, statistically significant reductions from baseline gingivitis and bleeding scores were found for all groups (p < 0.0001), but there were no significant statistical differences among groups. Whole mouth and approximal plaque scores were significantly reduced from baseline in the manual floss and ID/F groups after 30 days of product use, with no significant difference between groups. Plaque reduction for both the manual floss and ID/F groups was significantly greater than the ID/P group. All interdental cleaning methods were safe as used in the study, with no evidence of oral hard or soft tissue trauma. CONCLUSION: The Oral-B Hummingbird was safe and effective in reducing approximal plaque and gingival inflammation, and provides a useful alternative device for interdental cleaning.     

Irradiance effects on the mechanical properties of universal hybrid and flowable hybrid resin composites.

OBJECTIVES: A potential problem with high-intensity lights might be failure of polymer chains to grow and cross-link in a desired fashion, thereby affecting the structure and properties of the polymers formed. The purpose of this study was to evaluate mechanical properties of resin composites polymerized using four different light-curing units. METHODS: A conventional quartz-tungsten-halogen (QTH) light, a soft-start light, an argon-ion laser, and a plasma-arc curing light were used to polymerize disk-shaped (9.0mm diameter x 1.0 mm high) and cylinder-shaped (4mm diameter x 8 mm high) specimens of a universal hybrid and a flowable hybrid composite. Biaxial flexure strength, fracture toughness, hardness, compressive strength, and diametral tensile strength were determined for each composite. RESULTS: The use of the plasma-arc curing light, a high-intensity light, resulted in significantly lower hardness for the universal hybrid composite compared with the hardness obtained using the conventional QTH and the soft-start units. Hardness was the only mechanical property that was adversely affected by the use of a high-intensity light. SIGNIFICANCE: High-intensity lights might affect some resin composite mechanical properties, but this effect cannot be generalized to all resin composites and all properties.     

Evaluation of a predictive model for implant surface topography effects on early osseointegration in the rat tibia model

STATEMENT OF PROBLEM: Alterations in commercially pure titanium (cp Ti) implant surface topography can be made to increase bone formation or the interfacial shear strength of bone at the functioning implant. It is not known whether these 2 goals are congruent or mutually exclusive. PURPOSE: The aim of this study was to determine the effect of implant surface topography parameters of calculated biomechanical significance on the process of bone formation in a rat tibia model of osseointegration. MATERIAL AND METHODS: Implants (cp Ti grade IV) were machined and subsequently treated by grit blasting or grit blasting and 6.4 mol/L HCl. Measurements of surface roughness were made by atomic force microscopic analysis of similarly treated titanium disks. Cleaned and sterilized implants (12 machined, 12 with nonideal pit morphology, 12 with ideal pit morphology) were placed into the tibiae of 400-g male Wistar rats by using a series of drills, irrigation, and a self-tapping procedure. After 3 weeks, tibiae were harvested and processed and embedded in methyl methacrylate resin. Polished sections were examined by backscatter electron microscopy, and the percentage implant surface contacting bone was measured with the Scionics PC image analysis program. RESULTS. The implants possessing a proposed ideal pit morphology supported significantly greater bone formation at the implant surface (54% +/- 7% bone-to-implant contact [P<.003]) than the nonideal pit morphology (40% +/- 15%) or machined surfaces (34% +/- 6%). CONCLUSION: Implant surfaces with a proposed ideal pit morphology (which possess a calculated biomechanical significance) enhanced bone formation at early periods after placement in the rat tibia model.     

Comparison of Gastrojejunal Anastomosis Techniques in Laparoscopic Roux-en-Y Gastric Bypass: Gastrojejunal Stricture Rate and Effect on Subsequent Weight Loss

Background

Different gastrojejunal anastomotic (GJA) techniques have been described in laparoscopic Roux-en-Y gastric bypass (LRYGB). There is conflicting data on whether one technique is superior to the other. We aimed to compare hand-sewn (HSA), circular-stapled (CSA) and linear-stapled (LSA) anastomotic techniques in terms of stricture rates and their impact on subsequent weight loss.

Methods

A prospectively collected database was used to identify patients undergoing LRYGB surgery between March 2005 and May 2012. Anastomotic technique (HSA, CSA, LSA) was performed according to individual surgeon preference. The database recorded patient demographics, relevant comorbidities and the type of GJA performed. Serial weight measurements and percentage excess weight loss (%EWL) were available at defined follow-up intervals.

Results

Included in the data were 426 patients, divided between HSA (n?=?174, 40.8 %), CSA (n?=?110, 25.8 %) and LSA (n?=?142, 33.3 %). There was no significant difference in the stricture rates (HSA n?=?17, 9.72 %; CSA n?=?9, 8.18 %; LSA n?=?8, 5.63 %; p?=?0.4006). Weight loss was similar between the three techniques (HSA, CSA and LSA) at 3 months (40.6 %?±?16.2 % vs 35.92 %?±?21.42 % vs 48.21 %?±?14.79 %; p?=?0.0821), 6 months (61.48 %?±?23.94 % vs 58.16 %?±?27.31 % vs 60.18 %?±?22.26 %; p?=?0.2296), 12 months (72.94 %?±?19.93 % vs 69.72?±?21.42 % vs 66.05 %?±?17.75 %; p?=?0.0617) and 24 months (73.29 %?±?22.31 % vs 68.75 %?±?24.71 % vs 69.40 %?±?23.10 %; p?=?0.7242), respectively. The stricture group lost significantly greater weight (%EWL) within the first 3 months compared to the non-stricture group (45.39 %?±?16.82 % vs 39.22 %?±?21.93 %; p?=?0.0340); however, this difference had resolved at 6 months (61.29 %?±?18.50 % vs 59.79 %?±?23.03 %; p?=?0.8802) and 12 months (71.59 %?±?18.67 % vs 68.69 %?±?22.19 %; p?=?0.5970).

Conclusions

There was no significant difference in the rate of strictures between the three techniques, although the linear technique appears to have the lowest requirement for post-operative dilatation. The re-intervention rate will, in part, be dictated by the threshold for endoscopy, which will vary between units. Weight loss was similar between the three anastomotic techniques. Surgeons should use techniques that they are most familiar with, as stricture and weight loss rates are not significantly different.