The bonding of glass ionomer cements to caries-affected primary tooth dentin

PURPOSE The purpose of this study was to evaluate the bonding of glass ionomer cements (GICs) to sound and caries-affected dentin by microtensile bond strength (μTBS) and nanoleakage (NL) tests. METHODS Occlusal cavity preparations were made in 36 sound primary molars. Half of the specimens were submitted to a pH-cycling model to create simulated caries-affected dentin. Teeth were randomly restored with one of the three materials: (1) resin-modified GIC with nanoparticles (Ketac N100; KN); (2) resin-modified GIC (Vitremer; VI); and (3) high-viscosity GIC (Ketac Molar Easy Mix; KM). Specimens were tested using a microtensile test (1 mm/minute). One specimen from each tooth was immersed in ammoniacal silver nitrate for 24 hours and revealed after eight hours to assess interfacial NL. The μTBS means were analyzed by 2-way analysis of variance and Tukey's post hoc test. For NL, Kruskal-Wallis and Mann-Whitney tests were used (P<.05). RESULTS No difference was found between sound and caries-affected dentin (P>.05). KM showed the lowest GIC-dentin μTBS values, while VI and KN showed higher values. Infiltration of ammoniacal silver nitrate into the adhesive interface was not affected by sound or caries-affected dentin. CONCLUSION Caries-affected dentin does not jeopardize the bonding of glass ionomer cements to primary tooth dentin.

Cancer of the oral cavity and oropharynx

Tumours in the oral cavity and oropharynx differ in presentation and prognosis and the detection of spread of tumour from one subsite to another is essential for the T-staging. This article reviews the anatomy and describes the pattern of spread of different cancers arising in the oral cavity and oropharynx; the imaging findings on computerized tomography and magnetic resonance imaging are also described. Brief mention is made on the role of newer imaging modalities such as [(18)F]fluorodeoxyglucose-positron emission tomography/computed tomography, perfusion studies and diffusion-weighted magnetic resonance imaging.

Significance of Periodontal Risk Assessment in the recurrence of periodontitis and tooth loss

Aim: To investigate the association of the Periodontal Risk Assessment (PRA) model categories with periodontitis recurrence and tooth loss during supportive periodontal therapy (SPT) and to explore the role of patient compliance. Material and Methods: In a retrospective cohort, PRA was performed for 160 patients after active periodontal therapy (APT) and after 9.5 ± 4.5 years of SPT. The recurrence of periodontitis and tooth loss were analysed according to the patient's risk profile (low, moderate or high) after APT and compliance with SPT. The association of risk factors with tooth loss and recurrence of periodontitis was investigated using logistic regression analysis. Results: In 18.2% of patients with a low-risk profile, in 42.2% of patients with a moderate-risk profile and in 49.2% of patients with a high-risk profile after APT, periodontitis recurred. During SPT, 1.61 ± 2.8 teeth/patient were lost. High-risk profile patients lost significantly more teeth (2.59 ± 3.9) than patients with moderate- (1.02 ± 1.8) or low-risk profiles (1.18 ± 1.9) (Kruskal–Wallis test, p=0.0229). Patients with erratic compliance lost significantly (Kruskal–Wallis test, p=0.0067) more teeth (3.11 ± 4.5) than patients compliant with SPT (1.07 ± 1.6). Conclusions: In multivariate logistic regression analysis, a high-risk patient profile according to the PRA model at the end of APT was associated with recurrence of periodontitis. Another significant factor for recurrence of periodontitis was an SPT duration of more than 10 years.

Apical surgery of a maxillary molar creating a maxillary sinus window using ultrasonics: a clinical case

AIM: To describe a method of carrying out apical surgery of a maxillary molar using ultrasonics to create a lateral sinus window into the maxillary sinus and an endoscope to enhance visibility during surgery. SUMMARY: A 37-year-old female patient presented with tenderness to percussion of the maxillary second right molar. Root canal treatment had been undertaken, and the tooth restored with a metal-ceramic crown. Radiological examination revealed an apical radiolucency in close proximity to the maxillary sinus. Apical surgery of the molar was performed through the maxillary sinus, using ultrasonics for the osteotomy, creating a window in the lateral wall of the maxillary sinus. During surgery, the lining of the sinus was exposed and elevated without perforation. The root-end was resected using a round tungsten carbide drill, and the root-end cavity was prepared with ultrasonic retrotips. Root-end filling was accomplished with MTA(®) . An endoscope was used to examine the cut root face, the prepared cavity and the root-end filling. No intraoperative or postoperative complications were observed. At the 12-month follow-up, the tooth had no clinical signs or symptoms, and the radiograph demonstrated progressing resolution of the radiolucency. KEY LEARNING POINTS: When conventional root canal retreatment cannot be performed or has failed, apical surgery may be considered, even in maxillary molars with roots in close proximity to the maxillary sinus. Ultrasonic sinus window preparation allows more control and can minimize perforation of the sinus membrane when compared with conventional rotary drilling techniques. The endoscope enhances visibility during endodontic surgery, thus improving the quality of the case.

Immunohistochemical localization of osteoclastogenic cell mediators in feline tooth resorption and healthy teeth

Tooth resorption is among the most common and most challenging problems in feline dentistry It is a progressive disease eventually leading to tooth loss and often root replacement. The etiology of moth resorption remains obscure and to date no effective therapeutic approach is known. The present study is aimed at assessing the reliability of radiographic imaging and addressing the possible involvement of receptor activator of NF kappa B (RANK), its ligand (RANKL), and osteoprotegerin (OPG) in the process of tooth resorption. Teeth from 8 cats were investigated by means of radiographs and paraffin sections followed by immunolabeling. Six cats were diagnosed with tooth resorption based on histopathologic and radiographic findings. Samples were classified according to a four-stage diagnostic system. Radiologic assessment of tooth resorption correlated very strongly with histopathologic findings. Tooth resorption was accompanied by a strong staining with all three antibodies used, especially with anti-RANK and anti-RANKL antibodies. The presence of OPG and RANKL at the resorption site is indicative of repair attempts by fibroblasts and stromal cells. These findings should be extended by further investigations in order to elucidate the pathophysiologic processes underlying tooth resorption that might lead to prophylactic and/or therapeutic measures. J Vet Dent 27(2); 75 - 83, 2010

Tooth wear and erosion: methodological issues in epidemiological and public health research and the future research agenda

This paper addresses methodological issues in the field of tooth wear and erosion research including the epidemiological indices, and identifies future work that is needed to improve knowledge about tooth wear and erosion.

Prosthetic rehabilitation and treatment outcome of partially edentulous patients with severe tooth wear: 3-years results

The purpose of this study was to report on the management and treatment outcomes of partially edentulous elderly patients with severe tooth wear.

[Multiple tooth resorption in an Italian greyhound]

An Italian greyhound was presented three times during a two-year period for dental prophylaxis due to periodontal disease. Clinical examination revealed lesions on several teeth. Radiographs revealed extensive resorptive root lesions. On histological examination, the presence of odontoclasts and signs of boney remodeling of the roots confirmed the resorptive nature of the lesions. Given the extent of the lesions, and poor prognosis with conservative treatment alone, teeth affected by the most severe resorption were extracted at each visit using a flap technique combined with alveolar vestibular osteotomy. Dental resorptive lesions are rarely detected in the dog but may be more frequent than previously thought. The routine use of dental radiographs can be used to reveal these lesions in the dog.

A history of frequent dental care reduces the risk of tooth loss but not periodontitis in older subjects

OBJECTIVES: Information on the significance of dental care in older adults is limited. We hypothesized that regular dental visits has an effect on the number of remaining teeth and periodontal conditions in older subjects. MATERIALS AND METHODS: 1020 randomly selected individuals age 60 - 96 from the Swedish National Study on Aging and Care Blekinge received a comprehensive oral health examination. RESULTS: Dentate women and men had, on average 18.4 teeth (SD +7.6,) and 18.9 teeth (SD + 7.5) respectively (NS). In the youngest group (60 and 66 years old) with less than one dental visit per year, 37% had >20 teeth, compared with 73% among those with at least annual visits. Among the old-old, comparable figures were 1.8 % and 37% respectively. Across age groups, bleeding on probing was 23 %.When adjusting for age, and number of teeth GLM univariate analysis failed to demonstrate an effect of dental visit frequency on alveolar bone loss (p = 0.18), the number of periapical lesions (p = 0.65), or the number of endodontically treated teeth ( p = 0.41). Frequent dental visitors had more teeth than infrequent visitors (p = 0.001). CONCLUSIONS: Tooth loss and alveolar bone loss severity increase with age. Individuals with regular dental visits retained more teeth but the frequency of dental visits had no impact on plaque deposits, gingival inflammation, or alveolar bone levels.

The impact of frozen sections on final surgical margins in squamous cell carcinoma of the oral cavity and lips: a retrospective analysis over an 11 years period

Taking intraoperative frozen sections (FS) is a widely used procedure in oncologic surgery. However so far no evidence of an association of FS analysis and premalignant changes in the surgical margin exists. Therefore, the aim of this study was to evaluate the impact of FS on different categories of the final margins of squamous cell carcinoma (SCC) of the oral cavity and lips.

Irregularities below the Enamel-Dentin Junction May Predispose for Fissure Caries

This study investigated the structure of the fissure fundus on occlusal surfaces with respect to the detection of possible irregularities below the enamel-dentin junction (EDJ). Occlusal surfaces were examined by micro-computed tomography (µCT). In total, 203 third molars with clinically sound occlusal fissures or non-cavitated lesions were selected. All specimens were scanned with µCT. Subsequently, each tooth was sectioned, and each slice was investigated by stereomicroscopy. In 7 of 203 molars (3.4%), demarcated radiolucencies below the EDJ were detected by µCT. These defects were obviously of non-carious origin, because the µCT images revealed no gradient of demineralization in the dentin. In all cases, a direct pathway between the oral cavity and the dentin was evident. The comparison of the µCT sites with conventional histological images also revealed defects in the dentin. These results demonstrate that demarcated radiolucencies below the EDJ may not necessarily be caries lesions according to µCT images and may be classified as possible developmental irregularities. To avoid misinterpreting µCT data, dental researchers should carefully consider this condition when analyzing µCT images. The clinical significance of this finding is that these defects may predispose molar teeth to early-onset caries in occlusal pits and fissures.

Clinical Study Monitoring the pH on Tooth Surfaces in Patients with and without Erosion

The aim of this study was to compare tooth surface pH after drinking orange juice or water in 39 patients with dental erosion and in 17 controls. The following investigations were carried out: measurement of pH values on selected tooth surfaces after ingestion of orange juice followed by ingestion of water (acid clearance), measurement of salivary flow rate and buffering capacity. Compared with the controls, patients with erosion showed significantly greater decreases in pH after drinking orange juice, and the pH stayed lower for a longer period of time (p < 0.05). Saliva parameters showed no significant differences between the two patient groups except for a lower buffering capacity at pH 5.5 in the erosion group.

Complication and failure rates of tooth-supported fixed dental prostheses after 7 to 19 years in function

The aims of this study were to reexamine patients who had received fixed dental prostheses (FDPs) more than 10 years prior, list the frequencies of observed technical and biologic failures and complications, and calculate the estimated failure and complication rates at 10 and 15 years.

Tactile sensibility of single-tooth implants and natural teeth under local anesthesia of the natural antagonistic teeth

The term osseoperception describes the capability of developing a subtle tactile sensibility over dental implants. The present clinical study aims at clarifying the question of how far tactile sensibility is to be attributed to the periodontium of the natural opposing tooth of the implant.