Journal of Dental Sciences

Resilon: a methacrylate resin-based obturation system

Deepti Shrestha, Xi Wei, Wan-Cui Wu, Jun-Qi Ling — 2010-06-01

A resin-based root canal filling material, Resilon/Epiphany was introduced to overcome the limitations of gutta-percha and other sealers. It is claimed that Resilon/Epiphany can enhance the sealing ability by forming a monoblock. Studies related to this material are summarized and discussed in this review article. Different in vivo and in vitro studies demonstrated that Resilon/Epiphany can be an alternative to gutta-percha and other sealers. However, other studies showed that there is still some room for improvement of the properties of the material in order to achieve quality three-dimensional obturation.

Compositional characteristics and hydration behavior of mineral trioxide aggregates

2010-06-01

Mineral trioxide aggregate (MTA) was one of most popular biomaterials for endodontic treatment in the past decade. Its superb biocompatibility, sealing ability and surface for tissue adhesion all make MTA a potential candidate for many dental applications, such as apexification, perforation repair, repair of root resorption, and as a root-end filling material. There are many review articles regarding the physical, chemical and biological properties of MTA. However, there are few reviews discussing the relationship between the composition and hydration behavior of MTA. The aim of this article was to provide a systematic review regarding the compositional characteristics and hydration behavior of MTA.

Potential biomarkers for the cytologic diagnosis of oral squamous cell carcinoma

2010-06-01

Unlike other deep cancers, oral squamous cell carcinoma (OSCC), which occurs in the oral cavity, is more easily monitored, and specimens for diagnosis are easier to collect. However, identifying reliable and sensitive markers for the early diagnosis and markers for identification of the recurrence of OSCC remains a challenge. This article mainly focused on reviewing recently identified potential biomarkers for a cytologic diagnosis during OSCC development. In addition, markers used in modern diagnostic technologies, including a sensitive labeling method and a photodynamic approach for cytologic diagnosis, are also described. Cytologic examinations using sensitive and specific biomarkers can improve the accuracy of the diagnosis. Hence, they can lead to appropriate treatment without delay and to the reduced recurrence of OSCC.

The association between the DMFS index and levels of salivary Streptococcus mutans and lactobacilli of subjects living in Erzurum, Turkey

Serpil Karaoğlanoğlu, Nilgün Akgül, Hayati Murat Akgül — 2010-06-01

Background/purpose: The objective of this study was to examine the association between the DMFS (the mean of decayed, missing, and filled permanent surfaces) index and levels of salivary Streptococcus mutans and lactobacilli of subjects living in Erzurum, Turkey. Materials and methods: The study was carried out on 133 subjects (62 females and 71 males) aged 20–50 years. To determine the DMFS values of subjects, oral examinations were done and S. mutans and lactobacilli levels were determined using a CRT bacteria kit (Ivoclar Vivadent AG, Schaan, Liechtenstein). Results: The prevalence of females with a level of S. mutans of 3 105 colony-forming units (CFU)/mL was 69%, while that of males was 65%. However, the prevalence of females with a level of lactobacilli of ≥ 105 CFU/mL was 95%, while that in males was 90%. It was determined that the levels of S. mutans and lactobacilli were not dependent on sex (P > 0.05). The average DMFS values of subjects whose S. mutans and lactobacillus levels were ≥ 105 CFU/mL were 19.58 ± 18.21 and 19.68 ± 17.30, respectively. Also, the average DMFS values of subjects whose S. mutans and lacto-bacillus levels were < 105 CFU/mL were 18.02 ± 14.18 and 11.50 ± 9.30, respectively. No statistically significant differences between the DMFS mean values and S. mutans or lactobacillus levels were found (P > 0.05). Conclusion: The present study showed that high S. mutans and lactobacillus levels in the saliva did not by themselves influence the DMFS index.

The oral health status and treatment needs of institutionalized children with cerebral palsy in Taiwan

2010-06-01

Background/purpose: In this study, we investigated the dental health status of children with cerebral palsy (CP) by determining their dental treatment needs in terms of different grades of disability, sex, and age. Materials and methods: In total, the dental health of 345 children with CP aged £ 18 years residing in institutions was examined, and their treatment needs were evaluated. Stratified cluster sampling by probability proportional to size was used for sampling. A dental examination was conducted according to the protocol criteria of the World Health Organization. A databank was designed using Microsoft Office Access, and SAS and JMP were used for the statistical analysis. Results: The deft (decayed, extracted and filled primary teeth) index in 5-year-old children with CP was 7.00 ± 6.73; the DMFT (decayed, missing and filled permanent teeth) index of 12- and 18-year-old children with CP were 2.50 ± 3.17 and 7.42 ± 5.48, respectively. The dental treatment needs increased with increasing age and the grade of disability. Children with a moderate grade of CP had the highest dental treatment needs. Conclusion: More decayed and missing teeth and fewer dental restorations are common problems in children with CP, and the conditions worsen with age. The grade of CP and having mental retardation or not also worsens their dental health. Promoting the oral health education of parents, caregivers and nurses, strengthening prevention programs from childhood, and motivating dental practitioners to create a dental care system for this population with disabilities are urgently required.

Multifactorial analysis of variables influencing the fracture strength of repair joints for provisional restorative materials using the statistically based Taguchi method

Chun-Jen Cheng, Chun-Li Lin, Yu-Fu Shan — 2010-06-01

Background/purpose: In this study, we investigated the relative contributions of design factors to the fracture strength of provisional materials after repair. Materials and methods: The Taguchi method was used to investigate the optimal design with respect to four different design factors: subject material, repair material, repair design, and connector thickness. Each factor was assigned three levels. Using the Taguchi L9 orthogonal array, nine rectangular bar-shaped experimental specimens with different parameter combinations were fabricated (n= 5) and tested with a three-point bending test. The fracture load (in newtons) of each specimen group was recorded. The Taguchi method was employed to identify the significance of each design factor in controlling the fracture strength. The sensitivity of each design parameter was determined using an analysis of variance. Fractographic analysis was performed to identify the adhesive or cohesive failure mode for each specimen. Results: The mean effect of the design factors at each level was determined. The subject material, with a contribution percentage of as high as 33.48%, had the most dominant effect on the fracture strength of the repaired provisional restorations, followed by the repair material (31.88%), connector thickness (19.70%), and joint design (14.94%). The strongest subject material was bis-acryl Protemp 3 Garant. The polymethyl methacry late material, Tempron, was the preferred repair material. A 4-mm connector thickness was the best level. A 45º bevel joint was superior to the butt or fiber joint. The predicted fracture strength of the optimum parameter combination (Protemp 3 Garant/45º bevel joint/Tempron/4 mm connector thickness) was 173.34 N. From the fractographic analysis, different bonding abilities between the same and different resin materials were investigated. Fiber joint groups were nearly all in the cohesive mode without complete catastrophic fracture. Conclusion: Within the limitations of this study, these four design factors had different contributions to the fracture strength of repaired provisional restorations. Clinicians must be aware of the sequence of importance in determining better problem-solving methods.

In vivo evaluation of poorly crystalline hydroxyapatite-based biphasic calcium phosphate bone substitutes for treating dental bony defects

2010-06-01

Background/purpose: Poorly crystalline hydroxyapatite was improved so that it has better cell affinity in vitro. We studied the efficacy of a novel resorbable poorly crystalline hydroxyapatite-based biphasic calcium phosphate, BonaGraft, for bone regeneration in vivo. Materials and methods: The beagle was used as an animal model, and cylindrical artificial bone defects (3 mm in diameter and 6 mm long) were produced in the alveolar bone. The BonaGraft (ratio of poorly crystalline hydroxyapatite to b-tricalcium phosphate, 60:40) was used to fill in the defect, and unfilled defects served as a control group. At 5, 8 and 10 weeks after the operation, the size of the residual graft and new bone formation were evaluation by a histomorphometric analysis. In a clinical trial, 33 enrolled patients included 15 males and 18 females with ages ranging from 35 to 54 years. The main indications were ridge augmentation (n = 12), sinus lifting (n = 2), repair of periodontal disease (n= 14), and repair of radicular cysts (n= 5). The clinical outcomes of the surgery were primarily evaluated by clinical radiographs. Results: In the animal study, implanting BonaGraft produced greater new-bone formation (74.5% ± 1.0%) at 10 weeks postoperatively than that of the control (40.2% ± 0.3%). BonaGraft particles were gradually resorbed and substituted by bone. The in vivo graft resorption time and bone healing time of 12.1 weeks were mathematically determined by the least squares method. In the clinical test, all patients implanted with BonaGraft reported satisfactory clinical outcomes without major material-related side effects. According to the radiographic pictures, implantation of BonaGraft enhanced bone formation. Conclusion: According to the animal study results, BonaGraft has a suitable resorption period and satisfactory outcomes of new bone formation. The clinical study produced high satisfaction with clinical results both objectively and subjectively. For this reason, BonaGraft seems to be an alternative choice for a bone substitute in dental applications.

Refractory apical periodontitis associated with a calculus-like deposit at the root apex

Cheng-Mei Yang, Yao-Dung Hsieh, Shue-Fen Yang — 2010-06-01

In this case report, we describe a refractory case in which a calculus-like deposit was found at the apical root surfaces of two adjacent teeth. This case involved a 45-year-old male with a sinus tract at the labial mucosa of the maxillary left central incisor, which did not heal after conventional root canal treatment of the maxillary left lateral incisor. Periradicular radiolucencies and unusual radio-opacities were noted on the root surfaces of the vital maxillary left central incisor and prior endodontically treated lateral incisor. Subsequent surgery found calculus-like particles at the root surface of both teeth. A pathology examination revealed calculus-like particles scattered in the granulomatous tissue. A test cavity confirmed pulp necrosis of the maxillary central incisor, and endodontic treatment was performed 1 year after surgery. At the 20-month recall, the size of the periapical radiolucency had decreased. The presence of calculus-like particles at the root surfaces was noted and may have possibly contributed towards the etiology of root canal treatment failure.

Application of a narrow-diameter implant in a limited space

Chia-Yun Tsai, Ching-Fang Tsai, Yu-Chuan Tseng, Jung-Chang Kung, Yi-Min Wu — 2010-06-01

This report presents a case of inadequate space distribution after orthodontic treatment, when a narrow-diameter implant was placed in a limited mandibular anterior space (ridge and prosthetic). A 26-year-old female patient presented with a purulent discharge from the mandibular right posterior area. Radiographic and clinical evaluations revealed a four-unit bridge spanning teeth 42 to 43 and acute apical periodontitis with root resorption around tooth 42. After careful evaluation, tooth 42 was extracted, and orthodontic treatment was performed to align the posterior teeth and create a dimensionally appropriate space between teeth 41 and 43. A 3i MicroMiniplant with dimensions of 3.25 mm (diameter) × 11.5 mm was implanted in the edentulous area of tooth 42 because of the small size of tooth 42. Autogenous bone particles were placed on the buccal crestal defect, and a healing abutment was attached. After an 8-month healing phase, a final impression was made and an all-ceramic crown was delivered. This case demonstrates that osseous sites with significant dimensional space limitations can be successfully utilized to receive and integrate a narrow-diameter implant that will satisfy esthetic, phonetic and functional requirements.