Corrosion of non –γ2– amalgams

Abstract – Abstract– Eight different dental amalgams were studied in an in vitro corrosion test. Cylindrical test specimens were stored in weak lactic acid solutions at different pH for 1 month. The concentrations of mercury and copper in the solutions were measured and corrosion depths estimated. The results indicated that more copper was released from non - γ₂ - amalgams compared with conventional ones. The amounts of copper from these amalgams were not directly correlated to the concentration in the alloys. Mercury was released in much lower amounts than copper for all amalgams and seemed to originate from the γ₁-phase. A low pH promoted the corrosion.     

Resonance frequency measurements in vivo and related surface properties of magnesium-incorporated, micropatterned and magnesium-incorporated TiUnite®, Osseotite®, SLA® and TiOblast® implants

Objective: To investigate implant stability using resonance frequency measurements of topographically changed and/or surface chemistry‐modified implants in rabbit bone. Material and methods: Six groups of microstructured, screw‐shaped titanium implants: two oxidized, cation‐incorporated experimental implants [Mg implants and MgMp implants with micropatterned thread flanges (80–150 μm wide and 60–70 μm deep)] and four commercially available clinical implants (TiUnite^®, Osseotite^®, SLA^®, and TiOblast^®) were installed in 10 rabbit tibia for 6 weeks. The surface properties of the implants were characterized in detail using several analytical techniques. Implant stability was measured using a resonance frequency analyzer (Osstell^?). Results: Surface characterization of the implants revealed microstructured, moderately rough implant surfaces varying 0.7–1.4 μm in S_a (mean height deviation), but with clear differences in surface chemistry. After 6 weeks, all implants showed statistically significantly higher increases in implant stability. When compared with one another, MgMp implants showed the most significant mean implant stability quotient (ISQ) value relative to the others (P≤0.016). In terms of increment (ΔISQ) in implant stability, MgMp implants showed a significantly greater value as compared with Osseotite^® (P≤0.005), TiOblast^® (P≤0.005), TiUnite^® (P≤0.005), SLA^® (P≤0.007), and Mg implants (P≤0.012). In addition, transducer direction dependence of resonance frequency analysis (RFA) measurements was observed such that the differences in the mean ISQ values between longitudinal and perpendicular measurements were significant at implant placement (P≤0.004) and after 6 weeks (P≤0). Conclusion: The present study found that implant surface properties influence RFA measurements of implant stability. Surface chemistry‐modified titanium implants showed higher mean ISQ values than did topographically changed implants. In particular, cation (magnesium)‐incorporated micropatterns in MgMp implants may play a primary role in ΔISQ.     

Treatment of replacement resorption with Emdogain® − a prospective clinical study

The present clinical study investigated the outcome of intentional replantation using Emdogain for periodontal healing following trauma‐related ankylosis. Sixteen ankylosed teeth affected by replacement resorption were treated as follows: After tooth extraction, the root canal was obturated with a retrograde titanium post. Emdogain was applied to the root surface and into the extraction socket with subsequent replantation of the tooth. Evaluation parameters included horizontal and vertical Periotest scores, percussion sound and periapical radiographs. All findings were compared to those of the adjacent teeth. The mean follow‐up period was 15 months (range 4–24 months). Eleven teeth showed no signs of recurrence of ankylosis: they were in full function and exhibited no pathological clinical findings. Four severely traumatized teeth demonstrated a recurrence of ankylosis after a mean period of 6 months, one tooth was lost in a second accident after 7 months. The estimated probability of 1 year without recurrence of ankylosis was P = 0.66 (95% confidence interval [0.40; 0.94]). The mean survival time was 10.2 months (SD 1.1). The results indicate that treatment of replacement resorption following light to moderate trauma with replantation and Emdogain appears to prevent or delay recurrence of ankylosis in many cases.     

Comparison of ready-to-use EMDOGAIN®-gel and EMDOGAIN® in patients with chronic adult periodontitis

OBJECTIVES: The aim of this multicenter trial was to compare the clinical and radiographical outcome of a ready-to-use Emdogain-gel (test) with the marketed Emdogain (control). METHODS: Subjects with bilateral infrabony defects > or =4 mm deep and > or =2 mm wide according to radiographs were selected. 88 subjects with probing pocket depth (PPD) > or =6 mm > or =1 month after supervised oral hygiene and scaling participated. At baseline plaque index, bleeding on probing, PPD and probing attachment level were recorded and reproducible radiographs for computer-based bone level measurements were taken. In each subject, 1 tooth was randomly treated with the test and 1 tooth with the control gel. Examinations were repeated 8 and 16 months post-operatively. RESULTS: After 16 months, the mean test PPD was 4.1 mm and the mean control PPD 4.2 mm. The mean gain of attachment was 2.7 mm for test and 2.9 mm for the control sites, and the radiographic measurements demonstrated a mean gain of 1 mm for both test and control sites. CONCLUSION: This series of cases demonstrated a statistically significant reduction of pocket depths and gain of attachment and bone after 8 and 16 months with no difference between the 2 preparations.     

Treatment of avulsed teeth with Emdogain®– a case report

Abstract –  The present case report describes the reimplantation of avulsed teeth with the treatment of Emdogain^®. Case was avulsed right maxillary permanent central and lateral incisor in a 9-year-old girl suffering from a traumatic injury. After pretreatment of avulsed teeth, Emdogain^® was applied to the root surface and into the extraction socket with subsequent replantation of the tooth. Evaluation parameters included horizontal and vertical percussion sound and periapical radiographs. At 1–2–6–12-month follow-up period, the clinical and radiographic appearance of the teeth showed resolution of mobility and no signs of replacement resorbption.     

Orofacial and gastrointestinal hyperplasia and neoplasia in smad4+/− and elf+/−/smad4+/− mutant mice

Background:  Smad4 is vital to the roles of Smads 2 and 3 in transforming growth factor-beta (TGF)-β signal transduction, and inactivated Smad4 is common to human gastrointestinal cancers. The embryonic liver fodrin (ELF) is a β-spectrin that facilitates the nuclear translocation of activated Smad4.
Methods:  Smad4 ^+/− mice, known to develop gastrointestinal cancer, were crossbred with elf ^+/− mice. The smad4 ^+/− and smad4 ^+/−/ elf ^+/− offspring were autopsied as abnormalities developed.
Results:  In addition to polyps and adenocarcinomas of the stomach and duodenum, the smad4 ^+/− mice developed squamous cell carcinomas of the skin, oral mucosa and forestomach, benign neoplasms of connective tissue and lacrimal gland, and a lymphoma. The smad4 ^+/−/ elf ^+/− mice developed extensive hyperplasia and neoplasia of the gastric mucosa.
Conclusion:  These findings indicate that investigating interactions among smad4 , elf , and other genes involved in TGF-β signaling should be useful in further delineating the processes of neoplasia in a wide variety of tissues.     

Treatment of replacement resorption with Emdogain®– preliminary results after 10 months

Abstract – Ankylosis of traumatized teeth in children and adolescents may inhibit further development and growth of the corresponding jawbone. Therefore, ankylosed teeth should be removed. As an alternative treatment option to autotransplantation of a premolar, intentional replantation using Emdogain^® may be considered, provided the ankylosis is detected at an early stage or has only affected a small area of the root. Eleven ankylosed teeth presenting with replacement resorption were treated as follows: after tooth extraction, the root canal was treated extraorally and obturated by retrograde insertion of a titanium post. Emdogain was applied to the root surface and into the extraction socket with subsequent replantation of the tooth. During a mean follow-up period of 6.3 months, no signs of recurrence of ankylosis were noted. The horizontally and vertically measured Periotest scores were identical to those obtained on the adjacent teeth. These results suggest that intentional replantation using Emdogain may prevent or delay ankylosis of these replanted teeth.