Glaucoma after open globe injury at a tertiary care university hospital in central Saudi Arabia; cumulative incidence and risk factors

Objectives: To investigate the incidence and risk factors of glaucoma after open globe injury [OGI]

Methods: The medical records of all patients admitted with the diagnosis of OGI at the Department of Ophthalmology, King Abdulaziz University Hospital, Riyadh, Kingdom of Saudi Arabia and had undergone primary repair from January 1996 to December 2011 were retrospectively reviewed

Results: For the 15-year study period, 775 patients who underwent repair of an OGI were identified. The overall risk of post-traumatic glaucoma was 5.3% [41/775] with a mean +/- SD follow-up period of 12+/-6.5 months. Univariate analysis revealed that Zone II injury [p=0.027], penetrating ocular injury [p=0.0008], lens injury [p=0.011], vitreous hemorrhage [p=0.002], and presence of intraocular foreign body [p<0.0001] were significantly associated with glaucoma. Age of more than 18 years was critical [p=0.054]. Following logistic regression, penetrating ocular injury [p=0.019], lens injury [p=0.002], and vitreous hemorrhage were significant [p=0.037]

Conclusion: Glaucoma after OGI is not uncommon. Zone II injury, penetrating ocular injury, lens injury, presence of vitreous hemorrhage, and presence of an intraocular foreign body were significant risk factors for developing post-traumatic glaucoma

Laser refractive surgery in glaucoma patients

Glaucoma may not be an absolute contraindication to Laser-Assisted in situ Keratomileusis [LASIK], but so far it is a relative one. People who are glaucoma suspects or who have glaucoma are just as likely as any other to seek laser refractive surgery. LASIK is a popular ocular procedure, relatively pain free and it is carried out with an extremely precise computer-controlled excimer laser emission. On the other hand, glaucoma is a group of diseases manifested by optic nerve damage with visual field changes. Patients that undergo a transient but significant rise in intraocular pressure during LASIK procedure have risk of further optic nerve damage. Furthermore, steroids which are typically used after refractive surgery can increase intraocular pressure [IOP] especially in steroid responders, who are more prevalent among glaucoma patient. Glaucoma patients interested in LASIK surgery may visit a glaucoma specialist or another LASIK surgeon who has had experience with performing LASIK in glaucoma patients. PRK [photorefractive keratectomy], LASEK [laser epithelial keratomileusis] are good alternatives for glaucoma patients. Refractive surgeons might want to consider giving patients a photo of their optic nerve, or a drawing, or an objective record of their preoperative examination

effect of three different surface textures on the bond strength between porcelain and electroformed gold using air abrasion

This study was carried out to evaluate the effect of three different electroformed gold surface textures and the use of bonding agent on electroformed gold-porcelain and strength. Thirty samples were constructed from base metal alloy in the form of discs, each disc has a diameter of 10 mm and a thickness of 2 mm, they were coated with electroforming gold 0.2 mm thick. The electroformed gold surface was air-abraded with 50 micro, 150 micro, 250 micro aluminum oxide abrasive powder. The resultant three groups of different surface textures were subdivided into 6 subgroups according to the application of bonding agent or not. The bonding agent [Glvano-bonder] was applied on the electroformed gold surface of three subgroups only, one from each group, surfaces coated with bonding agent were evaluated microscopically after firing of the bonding agent. Omega opaque and body porcelain was applied in all electroformed gold surfaces with bonding or without bonding, to form a cylinder of porcelain 4mm in diameter and 6mm in height. The samples were tested for the shear bond strength using a universal testing machine. Bond strength values were calculated and analyzed statistically using Mann-Whitney U test. Further more; the samples were studied microscopically using scanning-electron microscope and stereomicroscope, after air-abrasion with the three different particle sizes of aluminum oxide abrasive powder, to evaluate the surface texture, and after debonding at the debonded surfaces, to evaluate the mode bonding failure. The results showed that, the increase in particle size of aluminum oxide powder, showed a significant effect on the electroformed gold bond strength values, through the increasing of surface roughness and that the exclusion of the bonder with rough air abrasion [250 micro] provided acceptable bond strength

benefit of ultrasound biomicroscopy in localization of anterior chamber angle foreign body

Anterior chamber foreign bodies often result from perforating ocular injuries and it should be considered as ocular emergency. We are reporting a 28-year-old man with post-traumatic metallic anterior chamber angle foreign body [FB]. Diagnosis was made by history, ocular examination, orbital x-ray and computed tomography [CT]. Localization was established by help of ultrasound biomicroscopy [UBM]. The foreign body was extracted through limbal incision opposite to FB entry site with good visual outcome

Weibull analysis method of assessing the mechanical properties of brittle dental materials

Weibul analysis is a new technique in dentistry to evaluate the mechanical properties of dental materials. The aim of the current work is to explain the different steps needed to estimate the Weibull modulus and then to estimate the amount of stresses generated within the material before failure. Three groups of dental composite [207 group] were tested for flexural testing and were compared by normal statistics ways. Different excel sheets were generated to estimate the value of Weibull modulus followed by calculating the amount of stresses generated within each material before failure. Stresses for 95% chance of fracture [MPa] for groups A to C were 104.45, 89.81 and 62.80 respectively. Stresses for 5% chance of fracture [MPa] for groups A to C were 131.91, 143.11 and 152.94 respectively. Weibull analysis is a useful tool for assessing the mechanical properties of dental materials

In vitro study of the effect of different post and core systems on shade and fracture resistance of all-ceramic crowns

This study was conducted to compare and evaluate the influence of three post and core systems on the shade of all ceramic crowns by spectrophotometric analysis namely, zirconia post [cos-mopost] with composite core, Cast metal post and core with opaque porcelain on the core and Cast metal post and core without opaque porcelain. Also to compare the fracture resistance of endo-dontically treated teeth restored with these different post and core systems. Twenty-one extracted maxillary central human incisors were selected of the same shape, size and root length. The anatomical crowns of all teeth were reduced perpendicular to the long axis of the roots. The remaining tooth length was standardized at 16 mm. Endodontic procedures were performed. The remaining coronal portion was prepared creating 1mm shoulder finish line with rounded axiogingival line angle cir-cumferentially at the level of CEJ leaving 2 mm of intact tooth structure above the finish line. The teeth were then equally divided into three groups 7 teeth each according to the type of post and core system. The cementation of the posts was done according to the manufacturer's recommendations using variolink II resin cement for all the groups Duceram crowns of similar size and shape were constructed on the refractory die following the manufacturer's instructions, using standardized technique, and then the crowns were cemented on their respective teeth using variolink II resin cement. All test groups were thermocycled between 5°C and 55°C. Color was measured by Ultra Scan XE spectrophotometer , the shade analysis was assessed by determining color difference [AE] between base line CIE L a b co-ordinate and standard Vita shade A3. All the specimens were tested on an Instron universal testing machine for evaluation of fracture resistance

Results: Cosmopost provided the best color quality in the incisal and cervical region while metal post and core without opaque porcelain provided the least shade quality in comparison with other two groups. Metal post and core with opaque porcelain provided proper shade at the incisal region but at cervical area, it failed to provide the same shade. Metal post and core without opaque porcelain provided the highest fracture resistance followed by metal post and core with opaque porcelain followed by cosmopost with composite core

Study of fit, microleakage and shear bond strength of CAD-CAM fabricated porcelain laminate

The aim of this work was to evaluate the Cerec 1, Cerce 2 and the conventional porcelain laminate veneers in terms of fit, microleakage and shear bond strength to the tooth surface. Thirty maxillary central incisors were used for the fit and microleakage tests. They received standardized preparations and were divided into three groups of ten each. Group 1, 2 and 3 were restored with Cerec 1 Cerce 2, and conventional laminate veneers respectively. Alter staining and thermocycling, the teeth with their bonded laminates were sectioned by two cuts [incisogingivally and misiodistally]. Fit and microleakage were evaluated by measuring the cement thickness and degree of dye penetration respectively using an image processing computerized stereomicroscope. For the assessment shear bond strength thirty other central incisors received flat preparations in enamel. Thirty porcelain specimens were fabricated using the above systems [ten specimens each] then bonded to the prepared enamel surface. After themocycling, a shear test was done using a universal testing machine. The debonded surface were then observed under a scanning electron microscope. Overall, the Cerec 2 CAD-CAM laminate veneers did overcome many of the disadvantages found in the Cerec 1 laminate veneers. The quality of the laminate veneers produced by the Cerec 2 CAD-Cam unit is comparable to the conventional laminate veneers

Effect of curing potential of resin cements on shear bond strength between ceramic and both dentin surface and core material

Statement of Problem: One of the most critical steps of the ceramic restoration technique is cementation. Mechanical stress before the resin cement reaches a certain degree of polymerization can displace or even fracture the restoration

Purpose of Study: This is in vitro study conducted to evaluate the bond between ceramic and dentin or core material, using two luting resin cements, also evaluated the degree of conversion after curing through different ceramic thickness

Materials and Methods: for shear bond test: 30 non-restored human molars and premolars and 30 cylindrical shapes of composite core materials were randomly divided into 12 groups. The two resin luting cements tested were "Rely -X with Scotch bond multi purpose" and "Admira cement with Admira bond". A total of 40 ceramic discs [2 and 3mm] were etched, silane coated and then bonded to a flat dentin and core surface with luting cements associated with adhesive system and then photoactivated. For degree of conversion test;- C = C converted to C... C were determined with infrared spectroscopy [FTIR] after light polymerization curing through Mylar sheet which served as control group. 2 mm and 3 mm ceramic thickness

Results: For the control groups when the cement cured without ceramic spacer, the shear bond strength is greater than other groups cured through ceramic discs. Both dual cure cement" Rely-X and light cure cement "Admira" give nearly similar results. The bond strength of resin cements to dentin is slightly higher than that bonded to core material. The degree of conversion of both tested luting cement show significant reduction as a function of ceramic thickness. It is important to be noted that there is no significant correlation between the degree of conversion and shear bond

Pulpal response, bond strength and scanning electron microscopic observations of recent dentinal adhesives in normal and sclerotic dentin

Adhesion between dention and restorative resins is of primary importance in clinical practice attaining a bond to dentin is complex mainly because is a vital tissue with a high water and organic content the current generation of dentin adhesives, shows greater promise than their predencessors, with bond strength to dentin often approaching those to enamel. The influence of surface treatment of two dentinal adhesives [scotchbond 2 and scotchbond multipurpose] having the same mode of action on the structure of the dentin was studies. The effect on the pulp was also evaluated. Shear bond strength to normal and sclerotic dentin was tested and their failure patterns were observed by SEM the conclusions obtained from this study are. 1- Scotchbond multipurpose was found to have better chance of resisting fracture than scotchbond 2. 2- The retention of the composite resin restoration and its marginal integrity are enhanced by the peneteration of resin into acidectched cross cut dentin. 3- Etching sclerosed dentin make the surface dentin les brittle and more permeable and further increase the bond strength. 4- The distance the resin penetrates depends on how far from the surface the tubules have been emptied thereby securing tags of sufficient length in the dentinal tubules, so as they remain in place and are not too easity pressed out or worn away. 5- The pulp response was favorable and leading to the production of reparative dentin. 6- The pulpal irriatation caused by acid etching of dentin for composite restorations is transitory only when the fillings have a good marginal seal and wall adaptation

Microleakage of several high-copper amalgam alloy systems: in-vitro study

Eight amalgam alloys representing various shapes of particle and copper percentage were used in this study. The products studied were In-diloy, Sybralloy, Jentalloy-III, Epoque, Cluster, Contour, Disper-salloy, and Cupralloy. The eight amalgam alloys placed in standardized class V cavities in freshly extracted non-carious molar teeth, were tested for marginal leakage to a radioisotope after thermal cycling. From the results of this study we can conclude that: 1- The marginal leakage around the different amalgams does not depend on the particle shape or distribution. 2 - Copper percentage would have no effect on the degree of leakage around the different restorations. 3 - After one year all amalgams tested showed a virtual reduction of microleakage

Fracture resistance of human teeth in different types of cavity preparation with sharp and rounded internal angles

This work was carried out on three types of cavities : 1.Class [I] conservative cavities were prepared in 40 molars, these cavities were then divided into three groups : A. Group [1] : Constituted of 20 class [I] cavities that were prepared in ten upper molars and ten lower molars where five upper and five lower cavities were prepared with rounded internal line angles. The other teeth were prepared with sharp internal line angles. B. Group [2]: Constituted of the remaining 20 class [I] cavities that were filled with non-gamma 2 amalgam in the same number of cavities and in the same number of teeth as in group [1] 2. Class [II] conservative cavities were prepared in the same number of teeth [molars], the teeth were classified similar to that of class [I]. 3. MOD conservative cavities were also prepared. The teeth were also classified similar to that of class [I] and class II. A compressive force was applied to fracture each tooth by the Instrom Universal Testing Machine. It was found that: 1. No significant difference in the fracture resistance of sharp versus rounded line angles, preparations in the filled and unfilled teeth with amalgam. 2. There was a significant difference between filled and unfilled teeth that cause fracture of teeth prepared with conservative preparations rather than those filled with gamma 2 amalgam. 3. There was a significant difference in the fracture resistance between simple cavities [Class I] and compound cavities [Class II] or complex types [MOD Cavities]