volume-43-issue-3-2018

COMPARATIVE STUDY OF PRIMARY STABILITY BETWEEN IMMEDIATE PLACED IMPLANTS AND DELAYED IMMEDIATE PLACED IMPLANTS IN MANDIBULAR SINGLE ROOTED TEETH

Mohab M. Magdy, Sherif S. Mohamed , Hala R. Ragab

> Show Abstract

INTRODUCTION: The timing of implant placement after tooth extraction has been a matter of discussion in dental implant treatment. Primary stability of the implant placed can be measured by the resonance frequency analysis (RFA) which is used to compare the primary stability of immediate and delayed immediate placed implants.
OBJECTIVES: This study was designed to compare between primary stability of immediate placed implants and delayed immediate placed implants using resonance frequency analysis device in mandibular single rooted teeth.
MATERIALS AND METHODS: Ten patients were selected from Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, Alexandria University divided into two groups, Group A: Five patients indicated for extraction of single rooted teeth had undergone implant placement immediately after tooth extraction (Immediate implant placement). Group B: Five patients indicated for extraction of single rooted teeth had undergone implant placement two weeks after tooth extraction (Delayed immediate implant placement).
RESULTS: For group A patients the average mean and standard deviation of the primary stability of the placed implants was 61.75 ± 8.21 ISQ units while for group B patients the average mean and standard deviation of the primary stability of the placed implants was 67.38 ± 11.59 ISQ units. After comparing these results it was shown that the average mean and standard deviation of the primary stability of all cases of group B is greater than the average mean and standard deviation of the primary stability of all cases of group A, which results in a t-value (student t-test) of 0.792 and the p- value of the study was 0.458 which is statistically insignificant.
CONCLUSIONS: There is no significant difference between the primary stability of immediately placed implants and delayed immediate placed implants.
KEYWORDS: Primary stability, Immediate placed implants, Delayed immediate placed implants.


> PDF
1

PREVALENCE OF THE OCCUPATIONAL HAZARDS AMONG MINISTRY OF HEALTH DENTISTS, ALEXANDRIA, EGYPT

Sherihan I. Yehia, Mona K. El Kashlan , Wafaa E. El-Din

> Show Abstract

INTRODUCTION: Dentists are exposed to various hazards due to their occupation. Identifying the most prevalent ones is required to develop preventive measures and coping strategies in order to reduce the effect of such hazards in the future.
OBJECTIVES: to assess the prevalence of the different occupational hazards among the Ministry Of Health dentists, in Alexandria.
MATERIALS AND METHODS: A sample of 900 dentists working in the different Ministry of Health facilities was randomly selected from the eight health districts of Alexandria governorate. A final sample of 750 dentists participated in the study with response rate of 83.33%. They were asked to complete a structured questionnaire, specially designed for the study, in order to assess their exposure to the different occupational hazards.
RESULTS: Most of participants suffered from stress (85.9%), followed by musculoskeletal disorders (85.6%) and 63.9% experienced a type of percutaneous injury. Furthermore 51.3% were exposed to radiation hazards, 44.4% and 42.66% were exposed to eye injuries and chemical hazards, respectively. The least prevalent hazard was hearing impairment where it was reported by only 8.8% of the study participants
CONCLUSIONS: Rheumatoid arthritis is an important risk factor for alveolar bone loss. The treatment of the RA induced rats with fish oil not only prevented the alveolar bone resorption and stimulated new bone formation, but also reduced relatively the level of rheumatoid factor in the blood.
KEYWORDS: Prevalence, occupational hazards, dentistry, Ministry of Health, Egypt.


> PDF
9

INFLUENCE OF OCCLUSAL LOADING LOCATION ON THE STRAIN DEVELOPED AROUND IMPLANTS WITH TWO DIFFERENT CREST MODULE DESIGNS (IN VITRO STUDY)

Marwan A. Aggag, Yousreya A. Shalaby,Mohammed S. Nassif3, Amir S. Azer

> Show Abstract

ABSTRACT
INTRODUCTION: Mechanical overload is thought to be one of the major causes of implant complications. The addition of micro threads increase linear length of coronal implant surface available for biologic width and allows some stress transfer and relieve the crestal stress and strain concentration in the coronal region.
OBJECTIVES: Was to compare the influence of occlusal loading location on the strain developed around implants with two different crest module designs.
MATERIALS AND METHODS: Ten Polyurethane test blocks in which implants were fixed at the maxillary left first premolar area. Specimens were divided into two parallel groups (n=5), Group (I) -implants, with micro threads, Group (II) implants with wide-groove threads. Strain gauges were connected to a strain meter to record the developed strain. A universal testing machine was used for load application up to 100 N. The data were statistically analyzed (p≤0.05).
RESULTS: Group I exhibited the lower mean micro-strain values (260.0 ± 192.6 με) than Group II (513.2 ± 108.2 με).There was statistically significant difference between both groups(p > 0.05).
CONCLUSIONS: Crest module designs affected the stress pattern induced around dental implants.
KEYWORDS: Implant, Crest module, Micro threads, Macro threads, Strain gauge.


> PDF
16

THE EFFECT OF COMPLETE AND PARTIAL CONTOUR ZIRCONIA COPINGS ON THE FRACTURE RESISTANCE OF ALL CERAMIC RESTORATIONS

Islam M Abdel Raheem,Sanaa H Abdel Kader, , Fayza H Al Abbassy,

> Show Abstract

ABSTRACT
INTRODUCTION Veneer chipping is a common failure of zirconia based restorations, especially in the presence of high occlusal loads. Modifying zirconia design may influence veneer chipping.
OBJECTIVES: Purpose of this study was to evaluate fracture resistance of complete and partial contour zirconia crowns.
MATERIALS AND METHODS: Twenty standardized epoxy resin dies, prepared to receive zirconia based crowns, were divided into 4 groups, 5 specimens each. Zirconia framework designs were: (a) Full contour zirconia crown (FC), (b) Partial contour zirconia coping with buccal veneering (PC), (c) Anatomically reduced zirconia coping with palatal and proximal collar (ARD) and (d) half mm zirconia coping without collar (CON) (control group). Dual scanning technique was done for the test groups to fabricate zirconia copings with the use of standardized resin patterns, while normal scanning was made for the control group. After milling and sintering of zirconia specimens, veneering was done for all desired surfaces. All crowns were adhesively luted to their corresponding dies, and subjected to thermal cycling and mechanical loading corresponding to one year clinical service. Single load to fracture was applied to all the specimens. Type of failure was recorded for each specimen, investigated visually then by using Stereomicroscope and SEM.
RESULTS: Complete and partial contour zirconia restorations showed high resistance to fracture. The presence of collar was insignificant for increasing fracture resistance, but had an influence on the fracture extension toward the proximal surface of the veneered restorations.
KEYWORDS: Zirconia- Complete contour – Partial contour- Fracture resistance- Veneer chipping- Veneered zirconia.


> PDF
22

MICRONUCLEI AS BIOMARKERS OF GENETIC DAMAGE IN ORAL SQUAMOUS CELL CARCINOMA

Nancy A. Shaaban, Hanaa S. Raslan, Omneya R. Ramadan, Ahmed MA. Habib, Eiman I. Zaki

> Show Abstract

ABSTRACT
INTRODUCTION: Oral cancer is a major health problem, causing high morbidity and mortality rates. Oral Squamous Cell Carcinoma (OSCC) accounts for 90-95% of all oral malignancies. The prognosis of OSCC is often poor due to the late discovery of most lesions, after they have reached a large size. Here comes the role of biomarkers of genetic damage that can have excellent use in early diagnosis of cancer. Micronuclei are small extranuclear bodies formed by chromosome fragments or whole chromosomes that lag behind at anaphase and are not incorporated into the resulting daughter nuclei but are covered by a nuclear membrane and resemble a small nucleus. Many investigators have already called micronuclei (MN) an upcoming biomarker of tumorogenesis. More than 90% of human malignancies originate from epithelial cells. Thus the MN test in exfoliated buccal epithelial cells could be used as an objective, non-invasive tool for biomonitoring the genetic damage in high risk human populations and for screening cellular alteration in OSCC cases.
OBJECTIVES: To assess the degree of genetic damage in the oral squamous cell carcinoma lesions using micronuclei as biomarkers.
MATERIALS AND METHODS: A total of thirty four participants; seventeen OSCC patients and17 healthy control subjects were included. Cytological smears were taken from the lesion of the OSCC cases as well as from the buccal mucosa of the control group subjects using a cytobrush. Cytological smears were stained using Papanicolaou stain and the number of micronucleated (MNed) cells per 1000 cells was determined for each subject.
RESULTS: There was a statistically significant difference between the number of MNed cells in the cytological smears of OSCC cases and those of the healthy control subjects.
CONCLUSIONS: The number of MNed cells increases significantly in cancer patients thus they can be considered as an important biomarker for genetic damage.
KEYWORDS: OSCC, MNi, genetic damage, early diagnosis, Pap stain.


> PDF
28

EFFECT OF TWO POLISHING TECHNIQUES ON SURFACE ROUGHNESS OF THREE DIFFERENT DENTURE BASE MATERIALS (AN IN VITRO STUDY)

Mai S. El-Din,Amr M. Badr,Emad M Agamy,Gehan F Mohamed

> Show Abstract

ABSTRACT
INTRODUCTION: A direct link was found between surface roughness, the accumulation of plaque and the adherence of microorganisms concerning acrylic resins. However, the surface properties of the new thermoplastic materials remain questionable especially after using the conventional finishing and polishing techniques. Studying surface properties of each material makes the recommendation of the proper techniques easier.
OBJECTIVES: This in vitro study intended to compare three types of denture base materials in regarding to the effect of different polishing techniques on their surface roughness.
MATERIALS AND METHODS: 36 specimens were incorporated in this study. 12 specimens were in each group. 3 groups were formed: Group A: Heat cured Polymethylmethacrylate (PMMA). Group B: Thermoplastic Polyamides. Group C: Thermoplastic Acetal. Dimensions of specimens were (20×20×3 mm) with projection at the side. Statistical analysis was carried out using two way analysis of variance (ANOVA).
Statistical significance was defined at P≤0.05. RESULTS: Technique no. 1 showed a high significant value in compared to technique
no.2 for polishing the tested materials. CONCLUSIONS: PMMA was the highest affected group followed by thermoplastic acetal and
the last affected group was thermoplastic polyamide. Prepolishing rubberizing with rubber bur improves the polishing procedure.
RESULTS: Remarkable improvement in the histology and the ultrastructure of the alveolar bone of rats in Group III was observed. Moreover, hematological values revealed significant decrease in the inflammatory condition of rats with induced RA after fish oil treatment.
CONCLUSIONS: Rheumatoid arthritis is an important risk factor for alveolar bone loss. The treatment of the RA induced rats with fish oil not only prevented the alveolar bone resorption and stimulated new bone formation, but also reduced relatively the level of rheumatoid factor in the blood.
KEYWORDS: Polymethylmethacrylate. Polyamides. Acetal. Surface roughness. Finishing. Polishing.
Abbreviations: Polymethylmethacrylate: PMMA.


> PDF
34

THE DIFFERENCES BETWEEN ACQUA AND CONVENTIONAL DENTAL IMPLANTS

Esraa F. Shams, Ahmed A. Sharara, Ahmed O. Sweedan

> Show Abstract

ABSTRACT
INTRODUCTION: Missing teeth were a problem in the 1950s and 1960s till the real use of titanium dental implants to restore teeth. Scientists tried hard over many years to improve the surface treatment of the dental implant in order to improve the function and longevity of it and to reduce the chances of its failure. New materials and techniques are used to change the surface texture, component, and its surface energy.
OBJECTIVES: Evaluation of the delayed placement of ACQUA dental implant versus the conventional type for replacement of maxillary premolar teeth.
MATERIALS AND METHODS: Study was conducted on 14 patients. Patients were divided equally into two groups. Group “A” patients received ACQUA Alvium Neodent dental implant while group “B” patients received conventional Alvium dental implants. All Patients had missing maxillary premolars teeth. Patients were between 27- 48 years old. All patients were operated under local anesthesia. The surgical stent was checked for proper seating in the planned site of the dental implant. A full thickness mucoperiosteal flap was performed. Follow-up was done daily for the first week, then weekly for the first month, then monthly for six months.
RESULTS: Clinically no edema was shown in all patients. Other clinical parameters were recorded during the follow-up period as the gingival index, implant stability, and presence or absence of infection. Radiographic results showed that there was a significant difference between ACQUA and conventional Alvium dental implant which proved the higher initial stability of ACQUA Alvium Implants compared to conventional ones. Marginal bone height did not show any significant difference between ACQUA implants and conventional implants.
CONCLUSIONS: ACQUA dental implant showed more primary stability than conventional Alvium implant. Additionally, ACQUA showed more bone intensity compared to the other type.
KEYWORDS: ACQUA dental implant, Conventional Alvium, Comparison, Osstell, CBCT.


> PDF
41