The removal torque of titanium implant inserted in rabbit femur coated with biomimetic deposited Ca-P coating

A number of experimental data on biomimetic deposition CaP (BDCaP) coating implants have reported promising outcomes by histological evaluation. But little is investigated on the role of the BDCaP coating and osseointegration mechanism by interface shear strength. To make a direct biomechanical comparison between the BDCaP coating implants and the uncoated rough titanium implants (control), a well-established animal model for implants removal torque testing was employed in rabbits, using a self-matching experimental design. All implants had an identical cylindrical screw shape without any macroscopic retentive structure. After 2, 4, 6, 8 and 12 weeks of bone healing, removal torque testing was performed to evaluate the interfacial shear strength of each implant type. The torqued implants were sputter-coated with gold for morphology observation and observed with a field-emission electron microscopy. Results showed that the interfacial shear strength of the BDCaP coating implants was similar to that of the uncoated rough implants at 2 and 4 weeks of healing. The mean removal torque values of the BDCaP coating implants were lower than those of control implants (P < 0.05) after 6 weeks of healing. The removal torque values for both types of implants revealed similar mean values after 8 and 12 weeks of healing; there were no significant difference between the two types of implants (P > 0.05). It can be concluded that the BDCaP coating implants had no beneficial effect on the interfacial shear strength at early bone healing stage.     

应用超声波非破坏性拆除固定修复体

随着人们对口腔美学要求的提高，烤瓷技术的应用越来越广，但烤瓷修复体的损坏，以及修复后基牙出现牙髓炎或根尖周炎的治疗，已成为临床医生颇感棘手的问题。按过去切割等破坏性拆除的方法，往往损坏修复体或使修复体变形，不仅增加病人的就诊次数，也增加了病人经济上的负担。本文利用超声技术对36例固定修复体作非破坏性拆除。取得较满意的效果。报道如下。材料和方法1研究对象选择1995～1996年由口腔修复科转至口腔内科病人共36人，男15人，女21人，年龄24～61岁。其中单冠13例，连冠3例，3个单位固定桥11例，3个位以上的固定桥9例。粘…     

铸造义齿中网状支架的设计

铸造义齿中网状支架的设计李景辉，宋培智，陈官辉，季秋杰，卢玉春，高银凤在可摘局部义齿修复中，网状支架的合理设计既增加了义齿的强度，又具有传递咬力、分散力、保护口腔内软硬组织的功能［１］。常用形态为园孔形、方格形、楼梯的，网状形、三角形、倒锥形、栅栏形...     

Can anti‐erosion dentifrices also provide effective plaque control?

To cite this article:
Int J Dent Hygiene 9 , 2011; 223–228
DOI: 10.1111/j.1601‐5037.2010.00480.x
Bellamy PG, Prendergast M, Strand R, Yu Z, Day TN, Barker ML, Mussett AJ. Can anti‐erosion dentifrices also provide effective plaque control? Abstract: Objective: While gingivitis and caries continue to be prevalent issues, there is growing concern about dental erosion induced by dietary acids. An oral hygiene product that protects against all these conditions would be beneficial. This study investigated the potential of two anti‐erosion dentifrices to inhibit plaque. Methods: This was a randomized, three‐period, two‐treatment, double‐blind, crossover study evaluating a stannous chloride/sodium fluoride dentifrice (SnCl₂/NaF, blend‐a‐med^® Pro Expert) and a popular anti‐erosion dentifrice (NaF, Sensodyne^® ProNamel^?). During Period 3, subjects were randomized to repeat one treatment to evaluate any product carryover effects. Each treatment period was 17 days. Test dentifrices were used with a standard manual toothbrush. Digital plaque image analysis (DPIA) was employed at the end of each period to evaluate plaque levels (i) overnight (am prebrush); (ii) post‐brushing with the test product (am post‐brush); and (iii) mid‐afternoon (pm ). Analysis was conducted via an objective computer algorithm, which calculated total area of visible plaque. Results: Twenty‐seven subjects completed the study. At all time points, subjects had statistically significantly (P ≤ 0.0001) lower plaque levels after using the SnCl₂/NaF dentifrice than the NaF dentifrice. The antiplaque benefit for the SnCl₂/NaF dentifrice versus the NaF dentifrice was: am prebrush = 26.0%; am post‐brushing = 27.9%; pm = 25.7%. Conclusions: The SnCl₂/NaF dentifrice provided significantly greater daytime and overnight plaque inhibition than the NaF toothpaste. When recommending dentifrice to patients susceptible to dental erosion, clinicians can consider one that also inhibits plaque.     

Smart materials in dentistry

Most dental materials are designed to have a relatively 'neutral' existence in the mouth. It is considered that if they are 'passive' and do not react with the oral environment they will be more stable and have a greater durability. At the same time, it is hoped that our materials will be well accepted and will cause neither harm nor injury. This is an entirely negative approach to material tolerance and biocompatibility and hides the possibility that some positive gains can be achieved by using materials which behave in a more dynamic fashion in the environment in which they are placed. An example of materials which have potential for 'dynamic' behaviour exists with structures which are partly water-based or have phases or zones with significant water content and for which the water within the material can react to changes in the ambient conditions. Such materials may even be said to have the potential for 'smart' behaviour, i.e. they can react to changes in the environment to bring about advantageous changes in properties, either within the material itself or in the material-tooth complex. The controlled movement of water or aqueous media through the material may cause changes in dimensions, may be the carrier for various dissolved species, and may influence the potential for the formation of biofilms at the surface. Some of these issues may be closely interrelated. Clearly, materials which do not have the capacity for water transport or storage do not have the potential for this sort of behaviour. Some materials which are normally resistant to the healthy oral environment can undergo controlled degradation at low pH in order to release ions which may prove beneficial or protective. It is doubtful whether such behaviour should be classified as 'smart' because the material cannot readily return to its original condition when the stimulus is removed. Other materials, such as certain alloys, having no means of transporting water through their structure, can display smart behaviour by undergoing predictable changes in structure in response to applied mechanical or thermal stimuli. It has been difficult to harness such behaviour to the benefit of patients but progress in this area is slowly being made.     

Pain and anxiety reduction using a manual stimulation distraction device when administering local analgesia oro-dental injections: a multi-center clinical investigation

OBJECTIVE: This study was designed to assess the effects of a manual stimulating distraction device (Isoflex referred to as Manual Stimulation Distraction Device or MSDD) for reducing pain and anxiety experienced with standard dental local anesthetic injections. Additionally, the memory recall effects on injection pain and anxiety were also explored. METHODOLOGY: Patients from different dental clinics were identified by their practitioners as requiring dental procedures under local anesthesia, in the same area on both sides of the mouth. A local anesthetic solution was injected on either the left or right side at different times by random selection; one side using MSDD, while the opposite side used a solution without MSDD. Each patient acted as his or her own symmetrical split-mouth control. The same dentist administered both injections, using identical technique and equipment for each side. Forty-six patients used the MSDD first with the injection, while 54 used MSDD second when they received the injection. Using 10-point visual analogue nominal and ordinal scales, pain and stress were recorded by the patient each time after receiving the injection. The results were pooled and subjected to statistical analysis. Student's paired t-test was employed to test for significant differences in pain and anxiety (stress) when injections were administered with and without MSDD. RESULTS: Results showed significant reductions in perceived pain and stress from local analgesia injections (p < 0.001) when MSDD was used. There was no correlation of pain reduction with age, gender, upper or lower jaw, with or without MSDD. There was a trend for pain and stress to be scored higher for those subjects who had a lower period since the first injection (POFI) scores. This was attributed to recent memory of pain, as POFI scores over one week were significantly lower (p < 0.05). Stress reduction for POFI scores greater than one week proved to be non-significant (p = 0.099). CONCLUSION: In this study, MSDD was effective at reducing pain and stress experienced with local regional analgesic injections.     

Augmentation of narrow ridges for implants rehabilitation--a review

The quantity of alveolar bone decreases mainly because of periodontal disease or loss of teeth causing bone resorption in both vertical and horizontal directions. Inadequate width of the alveolar ridge affects many parameters of implants placement and the final restoration. Placement of an implant in a narrow ridge without bone graft may harm the final esthetics and the long-term success of the implant rehabilitation. The purpose of this article is to review the basic principles of bone grafting and to discuss various grafting techniques for widening of the narrow ridge.     

1354 freshmen's dental investigation]

1354 freshmen have been investigated to discover the relationship between dental diseases and environments,living habits and personal sanitary conditions,because urban young men like sweet foods and snacks,the incidence of caries is greater in the cities than in the country,more people with tetracycline discolored tooth live in urban areas than in the rustic ones,which is due to dense living conditions, vulnerable to respiratory organs disease,medical conditions and convenience of taking tetracycline when ill;on the other hand,gingivitis is more common within the country students than within the city students,for those students from the country are used to brush their tooth after adolescence and usually have more dental calculus which is harmful to the gingiva.More than half of the investigated freshmen are ignorant of correct method of brushing and oral health and that is important factors of high rate of dental disease,according to the above reasons,the effective measures should educated to prevent dental disease.