THE EFFECT OF RIDGE HEIGHT ON RETENTION OF ACRYLIC AND FLEXIBLE DENTURES IN PATIENTS WITH COMPLETE EDENTULOUS MAXILLARY ARCH: A PILOT STUDY.

Introduction: Removable denture still stands as the preferred option in the management of completely edentulous arch in the developing society. The prosthodontist is challenged with providing a retentive denture to the patient, alleviating the effect of tooth loss. The retention of these prostheses is influenced by the material used for it fabrication and the edentulous ridge height, hence the need to assess the retention of acrylic and flexible complete denture and the effect of edentulous ridge height. Aim: This study was to assess and compare the effect of ridge height on retention of flexible and acrylic complete upper dentures. Materials and Methods: Ten patients with complete upper edentulous arches were recruited and randomly allocated into two groups (A and B). Acrylic and flexible, complete maxillary dentures were fabricated for each participant. Group A wore the acrylic denture first, while group B wore the flexible denture first. Each participant was recalled after using the denture for one week, one month, and three months for data collection.At cross over time (3 months after wearing the first denture), individuals in group A were given flexible dentures, while those in group B received acrylic dentures. The patients were recalled again for data collection by one of the researchers. Kapa Intra examiner reliability test was 83.3%. Information related to denture retention were obtained and entered into IBM SPSS software version 23 for analysis. Paired t-test and linear regression were used to test for association between quantitative variables. A P-value of 0.05 was regarded as significant. Results: Ten individuals with mean age of 66.5±9.7 years and mean anterior ridge height of 15.5 ± 2.95 mm participated in this study. The subjective and objective assessments of the dentures showed that acrylic denture possessed a better retention than flexible denture. The effect of anterior ridge height on retention, showed a statistically significant difference (p= 0.006 for acrylic denture, p = 0.001 for flexible denture). Conclusion: This study suggested that acrylic denture possesses better retention compared to the flexible type and far better in situation with lower ridge heights.

PROSTHODONTIC REHABILITATION OF MAXILLOFACIAL DEFECTS IN A NIGERIAN TEACHING HOSPITAL: A 9-YEAR REVIEW.

OBJECTIVE: The objective was to review patients treated with maxillofacial prostheses in a Nigerian teaching hospital to assess the types of prostheses provided for them. METHODOLOGY: This was a retrospective study of patients treated with maxillofacial prostheses over a period of nine years. The socio-demographic data of the patients, types of defect, causes of defects, location of defect, types of maxillofacial prostheses and the indications for prostheses were obtained from the patients' case records. Case records with incomplete information were excluded. All data generated were analysed using the IBM SPSS version 20. Fisher's exact test was used to test for statistical significance. RESULTS: Case records of eighty-two patients treated with maxillofacial prostheses were reviewed. Forty-three (52.4%) of the patients were males while 39 (47.6%) were females. The age ranged from 6 to 76 years with the mean age being of 38.76 (SD±18.3) years. The majority, 58 (70.7%) of the patients were of lower social-economic class. Sixty-six (80.5%) patients had prostheses for maxillary defects, while only one (1.2%) patient had prosthesis for nasal defect. Twenty (30.3%) of the 66 patients that had maxillary defects had definitive obturators, while only three (4.5%) had all the three types of obturator. Surgical recession of tumours of the jaw was the major cause (85.4%) and mastication (70.7%) was the major indication for the prescription of obturators. CONCLUSION: The majority of the patients were of the lower social class and maxillary obturator was the major form of maxillofacial prostheses provided for patients in this study. Most of the defects are caused by surgical recession of tumours of the jaw and mastication was the major indication for the prescription of obturators.

SURVIVAL OF REATTACHED TOOTH: A SYSTEMATIC REVIEW.

BACKGROUND: The use of tooth fragment reattachment as an alternative treatment for fractured anterior teeth has been widely reported. However, there is controversy about its longevity. This necessitates the review of studies on its survival rate. AIM AND OBJECTIVES: To determine the reported survival rate of reattached tooth fragments and to assess the storage media, techniques and materials used for tooth reattachment as it affects the longevity of the restorations. DESIGN OF THE STUDY: This is a systematic review of studies conducted on tooth fracture reattachment. SETTING: The review was carried out at the University College Hospital, Ibadan, a tertiary hospital in south-western region of Nigeria. MATERIALS AND METHOD: A systematic search of PUBMED, Cochrane, Web of science, Scopus, Google scholar and Google was done three times for better outcome. Case reports, observational studies, in vivo studies, and cross sectional studies that were written in English language were included. Key words and phrases such as 'tooth reattachment', 'fragment tooth reattachment', 'crown fragment reattachment' as well as 'AND' 'OR' were employed to increase the field of search. Articles downloaded were critically appraised by the two authors for inclusion. Data including authors' name, date, institution, age/gender of patient, teeth involved, medium of storage, technique of reattachment, materials used, and follow up period were extracted and entered into a data proforma. RESULTS: Search yielded 206 articles of which 61 relevant ones were downloaded and twenty five studies that met the selection criteria were analysed. A total of 29 teeth were treated in the studies. The majority, 20 (69.2%), of the patients were male and 15 (51.7%) of teeth treated were tooth-type 11. Ellis class III fracture constituted the major indication for reattachment, 21 (72.4%). Material mostly used for tooth reattachment was Light cured composite resin in 16 (55.2%) teeth followed by flowable composite in 8 (27.6%) and dual cure composite in 5 (17.2%) teeth. Follow-up period was between 3 months and 10 years with an average of 2-year-longevity and survival rate. CONCLUSION: Tooth reattachment as an alternative treatment for fractured anterior teeth is simple, conservative, cost effective and aesthetically pleasing with fair survival rate.

Dental caries prevalence and bilateral occurrence in premolars and molars of adolescent school children in Ibadan, Nigeria.

The aim of the study was to determine the prevalence of dental caries in premolars and molars of adolescent school children in Ibadan, Nigeria with a view of comparing findings from this study with previous African studies. A cross section of 12-19 year-old school children from the five local government areas in Ibadan were examined over a period of three months by two examiners (OD and DA), using the WHO criteria for diagnosing dental caries. Only premolars and molars were examined but the third molars were excluded because they were not fully erupted in most children. The mean age of the children under study was 16.2 ± 0.83 years. Dental caries was detected in 10.8% of the children. Overall, 225 teeth had dental caries, out of which 13.3% were premolars while 86.67% were molars. Among the molars, first molars were mostly affected by caries (68.72%) while 31.28% second molars were affected. Second premolars were more affected by caries among the premolars. Also bilateral caries occurrence was highest in the mandibular first molars. In conclusion since the first molars were the most vulnerable teeth to decay, caries preventive programs on them need to be drawn up.

Microwave disinfection of maxillary and mandibular denture bases contaminated with Candida Albican.

BACKGROUND: Oral environment is not sterile, and dentures worn by the patients can be infected and therefore needs disinfection. Solution disinfectants such as sodium hypochlorite and glutaraldehyde can be used but they have side effects. Microwave disinfection method is more recent, however, there are conflicting reports at the moment on the appropriate power and time regimen for disinfection of denture. OBJECTIVE: To determine the power and time regimen at which the disinfection of dentures can be achieved using microwave. METHOD: Forty-five acrylic denture bases were fabricated for each of the jaws and infected with solution of a stock Candida albicans and 30 infected bases were employed as control. These were placed in normal saline and then subjected to different microwave power and time regimen. Aliquots from these post-microwave solution were titrated against sabauraud agar which was subsequently incubated at 37 degrees C for 48 hours. The agar were examined for candida growth. RESULT: The denture bases subjected to microwave disinfection at 350W showed Candida growth after microwave treatment irrespective of the time employed. Conversely, those microwaved at 650W and 690W for four and six minutes showed no microbial growth. CONCLUSION: The microwave regimen of 650W at 4 and 6 minutes completely disinfected the denture bases. Disinfection at higher microwave energy should be done with caution as distortion of the denture may occur.

DENTAL IMPLANT TREATMENT AT A NIGERIAN TEACHING HOSPITAL.

BACKGROUND: There has been an increase in the awareness of dental implant as a replacement option for missing teeth and this has consequently led to an increased demand for dental implant. AIM & OBJECTIVES: To determine the distribution and pattern of implant placement in a tertiary hospital in a developing country. MATERIALS & METHODS: This retrospective study was conducted at the University College Hospital to assess the treatment outcome of all the patients who had had osseointegrated root form endosseous dental implants over a period of five years. The data obtained included age, gender, socioeconomic status (SES), medical history, reason for implant placement, number of implants per patient, distribution of missing teeth, complications and treatment outcome. The data were analyzed for percentages, means, SD and presented in tables and figures. RESULTS: Forty two implants (40 conventional & 2 immediate) were placed in the 23 patients (M-15, F=8).There were 15(65.2%) males and 8(34.8%) females. Pre-implant placement ridge augmentation was done in 3(7.1%) patients while 9 (39.1%) patients had augmentation during implant placement surgery. Left maxillary central incisor was the most commonly replaced tooth in 31% followed by the right maxillary central incisor in 19%. The success rates in the study at 1 year and 5 years were 97.4% and 95.2% respectively. CONCLUSION: A high success rate (95.2%) of implant therapy at 5 years recorded in this study compared favorably with what is obtainable in many other countries of the world.

Endodontic treatment of unusually long discolored maxillary central incisor: a case report.

BACKGROUND: Success in root canal treatment is achieved after thorough biomechanical preparation followed by complete obturation of the canal system together with prompt and adequate restoration. Therefore, the endodontic therapy requires specific and complete knowledge of the internal and external anatomy, and its variation in presentation. Such treatment may be performed in root canal systems that do not comply with normal anatomic features described in standard textbooks. This article presents a case of endodontic treatment in an unusually long discolored maxillary central incisor. CASE PRESENTATION: A 31 year-old male patient was referred to conservation clinic for endodontic treatment of discolored left maxillary central incisor with associated history of recurrent swelling. Root canal therapy was performed and patient was found to have an unusually long working length of 29mm. This was then followed by enucleation of apical cyst without apical resection. CONCLUSION: Though the patient presents a maxillary central incisor with canal length in the upper limit of some reported cases, it is unusual in our environment.

Survival of glass fiber post retained endodontically treated teeth preliminary report.

BACKGROUND: The use of fiber reinforced composite post in restoration of endodontically treated teeth have been found to prevent irreparable root fracture and the fact that the post is bonded to the root giving a monobloc restoration, also strengthens the tooth. This preliminary study aimed to evaluate the survival of endodontically treated teeth with compromised coronal tooth structure restored with glass-fiber posts after 6 months. METHODOLOGY: Twenty endodontically treated teeth with less than 50% coronal tooth structure, were assessed and restored with glass fiber reinforced post cemented with dual cure composite and porcelain fused to metal crown. Patients were recalled and the teeth re-assessed at 3 and 6 months to evaluate their survival. The criteria for success included post and core in situ with no displacement or detachment of the post, no crown or prosthesis decementation, no post, core, or root fracture and absence of periradicular conditions requiring endodontic retreatment. RESULT: Eighteen teeth were available for review at both 3rd and 6th months out of which none had post-core-crown fracture. One tooth (5%) had minimal crevice on probing the margin at 6 month's review, while another tooth had < or =1 mm mobility of the crown during the same review period. CONCLUSION: Within the limitation of the study, there was an excellent performance of the teeth restored with glass fiber post with respect to post -core- crown and root fracture at the end of the 6months recall visit.

Evaluation and treatment of failed amalgam restorations at Ibadan, Nigeria.

OBJECTIVE: Failure of tooth restoration is a major clinical problem of interest to patients, dentists and employers of labour. This study was designed to find out the average life span of amalgam as well as causes and management of failed amalgam restorations at the dental center, University College Hospital, Ibadan. The distribution of new caries in patients with this condition was also investigated. MATERIALS AND METHODS: This was an interventional study conducted among consenting patients who presented with failed amalgam restoration in our conservative clinic over a three-year period. Oral examination was conducted to detect primary caries and causes of failure of the restoration. Bitewing radiograph was taken where necessary. The following data were recorded: socio-demographic variables of the patients and their complaints; life span of the failed restorations and the treatment given. Summary statistics was generated. RESULTS: One hundred and forty three patients (54 males, 89 females) presented with 198 defective restorations. Sixty five (45.5%) of these had 118 new carious lesions which were majority occlusal cavities (66.9%). Fractured restoration was the commonest cause of failure. Management was variable, but replacement with amalgam was the commonest treatment. The average life span of restoration was 8.3 years. CONCLUSION: The average life span of amalgam restoration was 8.3 years and the major cause of failure was amalgam fracture. Replacement with amalgam was the commonest treatment.

A retrospective study of traumatic injuries to teeth at a Nigerian tertiary hospital.

BACKGROUND: Various aspects of dental trauma have been studied worldwide. Most of these were among children and adolescents. However, studies involving the adult population with traumatized anterior teeth are few. OBJECTIVES: The objectives of this study were to report the pattern of trauma to anterior and posterior teeth among the late adolescent and adult patients seen at the Dental Centre, University College Hospital, Ibadan, Nigeria, the time lapse between trauma and patient presentation, reasons for dental consultation, and the type of treatment received. MATERIALS AND METHODS: Data were extracted from the dental records of 146 patients with dental trauma that presented between May 2001 and June 2006. RESULTS: One hundred and forty six patients were studied (87 males, 59 females) Males sustained injury more than females. The highest occurrence of trauma was in the age group of 25-34 years and least in the >65 years. Falls accounted for 34.3% of causes followed by RTA (19.2%). Enamel-dentine fracture was the most common type of injury, seen in 73 (38.6%) of the traumatized teeth, 5 were avulsed and 20 posterior teeth had cuspal fracture. All the cases of avulsion and most (83.3%) of root fracture presented within 1 week of injury while teeth that presented late had pulpal necrosis. 22% of the patients presented within 1 week of injury while 13.7% came after 10 years. CONCLUSION: There was late patients' presentation with average duration of trauma before presentation being 4.6 years; however the more severe the outcome of trauma, the earlier the presentation. Poor esthetics followed by pain were the main complaints at presentation.

The prevalence and severity of dental fluorosis among secondary school children in Ibadan, Nigeria.

OBJECTIVES: This study was conducted to determine the prevalence and severity of dental fluorosis among secondary school children in Ibadan, Nigeria. MATERIALS AND METHODS: A multi-stage sampling technique was employed to select the participants who consisted of children aged 12-14 years taken from eleven randomly selected secondary schools in the five local government areas of Ibadan Metropolis. The children were examined by the Principal Investigator after submitting parental administered questionnaires. The diagnosis of dental fluorosis was based on the TF index. RESULTS: The mean age of the 1372 participants (825 males and 547 females) was 13.15 ± 0.80 years. Dental fluorosis was diagnosed in 157 (11.4%) children (98 males and 59 females). There was no statistically significant difference between age or gender and the occurrence of fluorosis. Most of the cases were very mild with greater than 90% of the affected teeth having a TF score of ≤3. The most severely affected were the maxillary molars. Severe disfiguring cases of dental fluorosis were not common among the secondary school children examined. CONCLUSION: The prevalence of dental fluorosis was found to be low, with majority of the cases being very mild.

Coronal tissue loss in endodontically treated teeth.

AIM: To categorize the endodontically treated teeth according to the extent of coronal tissue loss in order to determine the appropriate restoration required. MATERIAL AND METHODS: A two year descriptive study was done at the Conservative Clinic of the Department of Restorative Dentistry, Dental Centre, University College Hospital, Ibadan. Successful endodontically treated teeth were assessed and categorized according to the extent of tissue loss based on standard criteria proposed by Smith and Schuman. RESULTS: Two hundred and ninety endodontically treated teeth were assessed for success both clinically and radiographically. Eighty (27.6%) were anterior teeth, 78 (26.9%) were premolars while 132 (45.5%) were molars. Dental caries was found to be the most common (61.4%) indication for endodontic treatment and caused more coronal tissue damage (moderate and significant) when compared with other indications for endodontic treatment. Two hundred and twenty seven (78.3%) endodontically treated teeth had moderate coronal tissue loss, 41 (14.1%) had minimal damage while 22 (7.6%) had significant tissue damage. Dental caries was the most common indication for endodontic treatment of the posterior teeth while trauma was the most common indication for the anterior teeth. CONCLUSION: Majority of the endodontically treated teeth that were evaluated for tissue loss had moderate coronal tissue damage. It is therefore recommended that proper and prompt evaluation of the remaining coronal tooth tissue following successful endodontic treatment be carried out in order to determine the appropriate definitive restoration required that will be easy for the clinician and less expensive to the patients.

Barriers to oral health care utilization in Ibadan, South West Nigeria.

BACKGROUND: Barriers to oral health utilization are many, but those that are significant for our environment are not yet clear. The current study was designed to identify and graduate the barriers to receipt of oral health care among a cross-section of patients attending our centre. We also investigated the influence of socio demographic factors on the highly rated barriers. METHODS: This cross-sectional study was conducted among patients visiting UCH, Ibadan using a self-administered questionnaire. Socio-demographic variables and oral health care seeking behaviour were requested and in addition, the respondents were asked to rank 11 listed barriers to receipt of oral health care and any other barriers they may think of in order of strength. Factor analysis was employed in order to identify four factors with the highest loading. The mean scores were compared using t-test and one-way ANOVA and the level of significance was set at 0.05. RESULTS: Only 400 questionnaires were properly filled (84.9%) out of the 471 that were administered. The mean age of these participants was 37.85±15.38 years. Most of the respondents (55.8%) consulted the dentists only when there was pain while 109(27.3%) had never visited the dentist. Fear of dental injection, cost of treatment, feeling of insecurity when the dentist is operating and disturbing noise from dental drill were the major barriers. There was a statistically significant association between age groups and feeling of insecurity (p=006). CONCLUSION: The major barriers to oral health care utilization among our patients were fear related.

Prevalence of neck and back pain among dentists and dental auxiliaries in South-western Nigeria.

Dental health workers like other workers have occupation related health problems and hazards which include neck and low back pain. Previous studies have shown that the prevalence and location of pain may be influenced by posture and work habits and as well as demographic factors. The aim of this study was to determine the prevalence of neck and back problems among dentists and dental auxiliaries in private and government dental hospitals in south western Nigeria. Structured self administered questionnaire was sent to dentist and dental auxiliaries by randomly selecting 3 out of the 6 state capital from the southwestern Nigeria. Participants included those in private clinics, teaching hospitals and general hospitals. The questionnaire was composed of respondents biodata, questions about specific information on neck and back pain and routine practice posture while working at chairside. The total number of properly filled questionnaire was 210 with a male to female ratio of 1.04:1. Respondents included 147 dentists, 37 dental surgeon assistants (DSA), 14 dental therapists and 12 dental technologists. Prevalence of back and neck pain among the respondents was 88.1% and 81.9% respectively. Among the male respondents, the prevalence of back pain was 86.9% and 89.3% in female while for neck pain, the prevalence was 83.2% in male and 80.6% in female. Within the different professional groups, the prevalence of back pain was highest among the DSA (89.2%), closely followed by the dentists (88.4%), then therapists (85.7%) and least among the technologists (83.3%). For neck pain, the prevalence was highest among therapists followed by technologists, dentists and least among the DSA. More females missed work due to back and neck pain than males. There is therefore the need to address ergonomic issues and change the way dentistry is practiced.

A comparison of clinical and radiographic caries diagnosis on posterior teeth of children seen at a Nigerian teaching hospital.

Early detection and initiation of therapy for dental caries is the most effective means of ensuring resolution of the condition and its sequelae. The aim of this study was to compare the effectiveness of clinical and radiographic (using bitewing radiograph) methods of caries diagnosis in children. The subjects were 172 children within the age range of 5-12 years attending the Paedodontic Clinic of the University College Hospital for the first time. They were clinically examined for the presence of dental caries using the WHO criteria. Left and right bitewing radiographs were taken following the clinical examination to detect dental caries. Clinical examination found additional 4 occlusal caries (incipient caries) that were not diagnosed radiographically and radiographic examination revealed additional 20 approximal surface caries that were not evident clinically in deciduous teeth. In permanent teeth, 3 additional occlusal caries were diagnosed clinically while only one additional approximal caries was diagnosed radiographically. These observations revealed the additional diagnostic value of bitewing radiograph in the diagnosis of approximal caries in children and the importance of clinical examinations in diagnosis of early occlusal caries (incipient caries) which are difficult to see on dental radiographs. In view of these findings, the use of bitewing radiographs combined with careful clinical examination will be of great advantage in early detection of caries in children.

Prevalence of neck and back pain among dentists and dental auxillaries in South-western Nigeria

Dental health workers like other workers have occupation related health problems and hazards which include neck and low back pain. Previous studies have shown that the prevalence and location of pain may be influenced by posture and work habits and as well as demographic factors. The aim of this study was to determine the prevalence of neck and back problems among dentists and dental auxillaries in private and government dental hospitals in south western Nigeria. Structured self administered questionnaire was sent to dentist and dental auxillaries by randomly selecting 3 out of the 6 state capital from the southwestern Nigeria. Participants included those in private clinics; teaching hospitals and general hospitals. The questionnaire was composed of respondents biodata; questions about specific information on neck and back pain and routine practice posture while working at chairside. The total number of properly filled questionnaire was 210 with a male to female ratio of 1.04:1. Respondents included 147 dentists; 37 dental surgeon assistants (DSA); 14 dental therapists and 12 dental technologists. Prevalence of back and neck pain among the respondents was 88.1and 81.9respectively. Among the male respondents; the prevalence of back pain was 86.9and 89.3in female while for neck pain ; the prevalence was 83.2in male and 80.6in female. Within the different professional groups; the prevalence of back pain was highest among the DSA(89.2); closely followed by the dentists(88.4); then therapists(85.7) and least among the technologists(83.3). For neck pain; the prevalence was highest among therapists followed by technologists ; dentists and least among the DSA. More females missed work due to back and neck pain than males. There is therefore the need to address ergonomic issues and change the way dentistry is practiced

Attitudes and perception of Nigerian dentists about shortened dental arch therapy (SDAT).

OBJECTIVE: The shortened dental arch therapy (SDAT) is a strategy to reduce complex restorative treatment in the molar area. By offering the partially dentate patients, a treatment option that ensures oral functionality, improved oral hygiene, comfort and possibly reduced costs, the SDA treatment approach appears to provide an advantage without compromising patient care. Despite these encouraging reports, it has been stated that there are few papers in the literature addressing clinical attitudes to SDAT. The current study is, therefore, designed to determine the attitude and perception of dentist in Nigeria about the concept. MATERIALS AND METHODS: A cross-sectional study was conducted using a self-administered structured questionnaire. The questionnaire employed by Sarita et al. was modified and employed as the instrument for data collection. The respondents were requested to provide information about their socio-demographic variables and their attitudes and perception of SDAT. The questionnaires were randomly distributed among general dental practitioners and residents (postgraduate doctors) in dental training institutions in Nigeria. RESULT: The clinical experience of most of the respondents was < or = 10 years. Most of the respondents were working in government institutions. Few of the respondents (36.1%) indicated that the concept was good for developing country like Nigeria and only few of the respondents (38.0%) agreed with the problem-oriented approach. Most respondents indicated that patients with shortened dental arches are not nutritionally less healthy and that, the oral functions and TMJ health of these patients is acceptable. CONCLUSION: It appears the attitude and perception of dentists in Nigeria as it relates to shortened dental arch concept is not impressive at the moment.

Dental Anxiety: Investigative and Management Techniques often Employed in a Cross Section of Nigerian Specialist Dental Clinics

Background: Information on the pattern of dental anxiety management in Nigeria is currently not available. Aim: The study was designed to determine the awareness and frequency of application of dental anxiety assessment questionnaires as well as the current pattern in the management of dental anxiety in Nigeria. Methods: The cross-sectional study was conducted using structured questionnaires distributed among dental residents and house officers in Nigerian dental schools. Information requested included demographic variables; frequency of presentation of dental anxiety; awareness and frequency of application of dental anxiety questionnaires. The respondents were also asked to rate the frequency of application of the outlined dental anxiety management techniques on a 5-point Likert scale. The median score and the range for each technique was determined and compared between the male and female respondents. Results: A total of 96 questionaires were sent out to dental surgeons of all grades. Response was obtained from 86 giving a response rate of 90. Only 23 (26.7) respondents were aware of dental anxiety questionnaires while only 13 (15.1) have seen the instrument applied. The percentage of patients with dental anxiety was estimated by the respondents to be 20. Behaviour therapy was the most frequently employed dental anxiety management technique. The female respondents employ behaviour therapy and intramuscular sedation more frequently. Conclusion: The awareness and frequency of application of dental anxiety questionnaires appeared poor. Behaviour therapy was the most frequently employed dental anxiety management technique. It appears the female respondents employ behavior therapy and intramuscular sedation more frequently

The fluoride content of drinking water and caries experience in 15-19 year old school children in Ibadan, Nigeria.

Fluoride, a trace element with anticariogenic benefit may either occur naturally or be added to drinking water sources. This study aimed at determining the fluoride level of the different drinking water sources in Ibadan, Oyo State, Nigeria and to relate this with the caries experience of secondary school children in the city. Sixteen samples of the drinking water sources from various locations in the five local government areas of the city were analysed for fluoride concentration. The locations were selected around the vicinities of the secondary schools used for caries study. Nine hundred and fifty five students aged 15-19 years randomly selected from eleven secondary schools in Ibadan metropolis were examined for dental caries over a period of 4-5 months. Only teeth with obvious cavitations were recorded as being carious using the WHO standard method. Teeth grossly covered with calculus and third molars were excluded. No radiograph was taken. The fluoride level of the different water sources was between 0.02 and 0.03 ppm. Forty-four (4.6%) of the children had dental caries. There was no statistically significant difference between either DMFT and gender (t = 0.67, p = 0.91) or DMFT and age (F = 1.488, p = 0.224). However, females had a slightly higher mean DMFT than males and the highest mean DMFT (2.67 +/- 1.15) was found among the 19-year-old children. Twenty-three (52.3%) of the students with caries had only one carious tooth while only two had four carious teeth each. In conclusion, both the fluoride level and caries prevalence were low.

Causes and pattern of fracture of acrylic dentures among patients seen in a Nigerian teaching hospital.

There is little information on the causes and pattern of fracture of acrylic dentures in Nigerian patients despite being the most frequently employed design in Nigeria. The aim of this study was to determine the average life span of acrylic dentures before fracture, the causes and pattern of fracture of acrylic dentures in a Nigerian population. All consecutive patients that presented with fractured acrylic dentures at the Dental Centre, University College Hospital, Ibadan between January and July 2006 and were willing to participate were recruited into the study. A structured interviewer-administered questionnaire was used to record data from the patients. The questionnaire focused on patients' demographic data, age of acrylic denture as at the time of fracture, causes and pattern of fractures. The data were analysed using SPSS Version 11. A total of sixty-two patients were included in the study. They presented with sixty-nine fractured dentures. Five were complete dentures while 64 were partial dentures. The average life span was 7.4 years +/- 6.6 (SD) years. Early fracture was seen in 9 (13.4%), intermediate fracture in 29 (42%), and late fracture in 31 (44.9%) cases. The commonest cause of fracture was mastication as seen in 30.4% of the cases while the least cause was fight (4.3%). The commonest site of fracture (34.8%) was the palatal plate around the crest of the edentulous ridge while fracture of wrought metal clasps was the least, occurring in 1.4% of cases. We recommend proper design with balanced articulation and more emphasis on compliance to post insertion instructions by patients to prevent early fracture of acrylic dentures. Also, reinforcing the acrylic denture base especially in stress bearing area may prolong the life span of these prostheses.