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Bone regeneration by recombinant human bone morphogenetic protein-2 around immediate implants: a pilot study in rats.

PURPOSE: Difficulties relating to bone regeneration that complicate immediate implant placement include buccal and/or lingual fenestrations, primary anchorage of the implants, and the need for protection from functional loading during the osseointegration period. The objective of this pilot study was to evaluate bone regeneration by recombinant human bone morphogenetic protein-2 (rhBMP-2) around immediate implants placed in maxillary sockets in rats. MATERIALS AND METHODS: A total of 16 cylindric 0.8 x 1.8-mm commercially pure, solid titanium Implants were placed immediately after gentle extraction of the maxillary first molar teeth of 8 male Wistar rats. The sockets were randomly divided into 3 groups: group 1 (n = 6) received rhBMP-2 with polylactic acid/polyglycolic acid copolymer-coated gelatin sponge carrier; group 2 (n = 5) received only the carrier; and group 3 (n = 5) received no grafting materials following placement The rats were euthanized at 90 days postsurgery for microscopic analysis. RESULTS: In group 1, the implant body remained submerged completely, including the coronal part, which was fully covered by a significant amount (30% of total height) of regenerated cortical bone, even though the implant could easily be pulled out by a tweezer at the time of placement. Close approximation between the implant surface and regenerated bone could also be detected, indicating good bone-to-implant contact. In contrast, only peri-implant bone regeneration occurred in group 2, and an approximate 0.3-mm coronal part of the implant remained exposed. When no grafting materials were used (group 3), almost one third of the total length of the implant was exfoliated out of the socket when no grafting materials were used. DISCUSSION AND CONCLUSIONS: Based on previous study and data from 16 sockets of the present study, it could be concluded that rhBMP-2 facilitated the regeneration of bone around immediate implants. In particular, the bone covering the coronal part could have been regenerated shortly after surgery, which helped to maintain the implant body inside the socket during the integration period in rats.

Animals↗

[Effect of acid etching on the primary enamel smooth surfaces. (3) A study of the etching times].

The purpose of this study was to investigate the influence of etching times for the effect of acid etching on the primary enamel smooth surfaces. Fifty labial surfaces of the extracted or exfoliated caries-free primary anterior teeth were used. The cleaning and polishing pretreatment used in this study was polishing with a brush cone (Howe-Neos-Dental Co.) with water at a low speed (600-6000 r.p.m.). The etchant used in this study was 40% phospholic acid gel and the etching times were 10, 30, 60, 90 and 120 seconds. All specimens were washed with an air water spray for 30 seconds after etching. The following observations were obtained using the SEM. 1. The shorter the etching time, the higher was the rate of the cases which did not show any prism structure. 2. The numbers of the cases which did not show any prism structure were: 4 (40%) out of the 10 in 10 seconds etching, 2 (20%) out of the 10 in 30 seconds etching and 1 (10%) out of the 10 in 60 seconds etching. All cases showed prism structure in 90 seconds and 120 seconds etching. 3. The most common etching patterns in all etching times were poorly structured etching patterns. 4. The longer the etching time, the higher was the rate of the cases which showed peripheral etching patterns. 5. Tooth to tooth differences in the etching effects and patterns were observed under the same etching times. Various etching effects and patterns on the same enamel surface were observed. 6. Among the etching times used in this study, 90 seconds was an adequate time for etching on the unground primary enamel smooth surfaces polished with a brush cone.

Acid Etching, Dental↗

Influence of approximal caries in primary molars on caries rate for the mesial surface of the first permanent molar in swedish children from 6 to 12 years of age.

The objective was to assess the influence on the caries rate for the mesial surface of the first permanent molar (6m) of the caries status of the distal surface of the second primary molar (05d) in children from 6 to 12 years of age. The study design was retrospective and included 374 children with an average of 5 sets of bite-wing radiographs. The mean age of the children was 6.7 years when the first bite-wing radiographs were taken and 11.5 years at the time of the latest radiographs included in the study. The approximal surfaces were classified according to a scoring system: 0 = no visible radiolucency, 1= radiolucency in the outer half of the enamel, 2 = radiolucency in the inner half up to the enamel-dentin border, 3 = radiolucency with a broken enamel-dentin border but with no obvious involvement of the dentin, 4 = radiolucency with obvious spread in the outer half of the dentin, and score 5 = radiolucency in the inner half of the dentin. The influence of the status of 05d on the caries rate for 6m (state > or =2) was assessed by using a model for dependence between the two neighbouring surfaces. Presence or absence of approximal caries in the distal surface of the first primary molars (04d) and/or the mesial surface of the second primary molars (05m) at the time of eruption of 6m was also related to the caries rate for 6m. The caries rate for 6m was 15 times higher if 05d had developed enamel/enamel-dentin border caries (state 2 or 3) compared to a radiographically sound 05d (state 0 or 1). No significant increase in the caries rate for 6m was found when 05d had deeper unrestored dentin caries than when 05d had superficial caries (state 2 or 3). Furthermore, for preventing caries in 6m, no benefit could be found from restoring an 05d with dentin caries with amalgam as opposed to leaving the carious lesion unrestored until exfoliation. The caries rates for 6m and 05d were 3.4 and 2.7 times higher, respectively, in the presence of dentin caries/restoration in 04d/05m compared to absence of dentin caries in these molar surfaces at the time of eruption of 6m. In conclusion, the caries rate for 6m depended on the status of 05d and increased 15 times if 05d had enamel/enamel-dentin border caries compared to a sound 05d. Deeper unrestored or restored dentin lesions in 05d did not result in a higher caries rate for 6m compared with more shallow carious lesions in 05d.

Chi-Square Distribution↗

In vivo effectiveness of laser fluorescence compared to visual inspection and radiography for the detection of occlusal caries in primary teeth.

The purpose of this study was to evaluate the in vivo effectiveness of laser fluorescence compared to visual inspection and radiography for the detection of occlusal caries in primary teeth. Fifty sites from 30 molars in 29 patients were selected and evaluated under standardized conditions by 2 previously trained examiners according to the 3 diagnostic methods. Histological examination served as gold standard after exfoliation or extraction. Values obtained for sensitivity, specificity and accuracy were 0.60, 0.90 and 0.73 for laser fluorescence, 0.82, 0.85 and 0.84 for visual inspection and 0.62, 0.73 and 0.67 for radiography, respectively. Considering only dentinal caries, values were 0.73, 0.95 and 0.90 for laser fluorescence, 0.61, 1.00 and 0.90 for visual inspection and 0.96, 0.81 and 0.85 for radiography, respectively. We conclude that for the detection of occlusal caries in primary molars laser fluorescence presents a similar accuracy when compared to visual inspection and radiography, although visual inspection showed better values for sensitivities for both enamel and dentin lesions.

Child↗

Morphology of enamel in primary teeth from children in Thailand exposed to environmental lead.

Lead is one of the major environmental pollutants and a health risk. Dental hard tissues have a capacity to accumulate lead from the environment. Eighty exfoliated primary teeth were collected from children residing around a shipyard area in southern Thailand, known for its lead contamination. The morphology of the enamel was examined by polarized light microscopy (PLM), microradiography (MRG), and scanning electron microscopy (SEM). The specimens derived from two groups of children, one group with high blood levels of lead (57 teeth) and one group having low blood levels of lead (23 teeth). The enamel irrespective of group appeared normal. However, in a majority of the specimens the enamel surface appeared hypomineralized, which was confirmed in SEM. No morphological changes connected to lead in blood could be found. The hypomineralized surface zone could possibly be attributed to an acid oral environment.

Child↗

Evaluation of various cleaning and polishing methods on primary enamel.

The purpose of this study was to investigate the effects of cleaning and polishing methods on primary enamel surfaces. Fifty-nine extracted or exfoliated caries free primary anterior human teeth were used. The cleaning and polishing methods used in this study were as follows: application of 10% NaOCl, polishing with a brush cone or a polishing brush at a low speed (600-6000 r.p.m.), polishing with a brush cone and various polishing pastes, cleaning with an air polisher Prophy-Jet or Quick-Jet with NaHCO3 powder and water. The following observations were obtained using the SEM: (1) Air polishing systems were useful for cleaning the enamel surface, (2) It was likely that materials such as organic films will remain on the enamel surface polished with a brush cone or polishing brush alone, and (3) The effect of 10% NaOCl application for 30 seconds was the lowest.

Acid Etching, Dental↗

Clinical evaluation of Dyract in primary molars: 3-year results.

PURPOSE: To evaluate the 3-year clinical performance of Dyract in primary molars. MATERIALS AND METHODS: In 55 children (aged 4-9 years) 91 restorations were placed and 76 were available for evaluation after 2 years. After 3 years, 40 teeth were exfoliated leaving 37 restorations for evaluation. RESULTS: During the entire study, four restorations failed and had to be replaced. One restoration fractured after 6 months and another after 1 year. Two other restorations were completely lost between the second and third year's evaluation. Furthermore, three restorations showed minimal recurrent caries, which did not need additional treatment. Wear of the restorations was considerable. However, this was also true for the point of reference for the wear measurement on the primary molars. The excellent handling characteristics and the low failure rate during the 3-year study suggest that this compomer is a reliable restorative material in primary molars.

Child↗

A clinical, radiographic, and scanning electron microscopic evaluation of adhesive restorations on carious dentin in primary teeth.

OBJECTIVE: The purpose of this project was to evaluate the performance of a dentin adhesive system on carious and noncarious primary dentin in vivo. METHOD AND MATERIALS: Forty-eight primary molars with carious lesions were randomly assigned to 2 different treatments: group 1 (control, n = 24)--All identifiable, irreversibly infected dentin was removed prior to the application of the bonding agent and restorative material; group 2 (experimental, n = 24)--Irreversibly infected dentin was partially removed prior to the application of the bonding agent and restorative material. The control and experimental teeth were clinically monitored every 3 months and evaluated 12 months after restoration. The teeth were extracted around the time of exfoliation and processed for scanning electron microscopy. RESULTS: Retention rate, marginal integrity, and pulpal symptoms were identical in both groups. Radiographically, the radiolucent area associated with the experimental restorations did not increase with time in 75% of the cases. For the control group, the adhesive system formed a hybrid layer. In the experimental group, there was morphologic evidence of the formation of an acid-resistant "altered hybrid layer." An acid-resistant tissue, resulting from the interdiffusion of adhesive resin within the area of carious dentin, was observed adjacent to and under the altered hybrid layer. CONCLUSION: Application of an adhesive restorative system to irreversibly infected dentin did not affect the clinical performance of the restoration.

Child↗

Morphological appearance and chemical composition of enamel in primary teeth from patients with 22q11 deletion syndrome.

Patients with 22q11 deletion syndrome have many and complex medical problems, including hypocalcemia and/or hypoparathyroidism. Odontological findings include enamel aberrations in both dentitions. In order to describe enamel morphology, chemical composition in primary teeth, and to investigate the relationship between medical history and morphological appearance, dental enamel was investigated in 38 exfoliated primary teeth from 15 children and adolescents. Morphology was studied by the use of a polarized light microscope, microradiography, scanning electron microscopy, X-ray microanalysis, and secondary ion mass spectrometry. The morphological findings were compared with medical history. The teeth showed, in principle, a normal morphological appearance with regard to prism structure. A high frequency of aberrations, such as hypomineralization, hypoplasia and extra incremental lines, were found. The majority of the aberrations were found around the neonatal line. There was a relationship between high numbers of medical problems in the patients and enamel deviations. The result supports the hypothesis of under-reporting of both hypocalcemia and hypoparathyroidism in patients with 22q11 deletion syndrome.

Adolescent↗

Maternal diabetes and changes in the hard tissues of primary teeth. III. A histologic and microradiographic study.

According to clinical studies, infants of diabetic mothers (IDM) seem to run a higher risk of mineralization disturbances in the enamel than normal healthy infants. In order to evaluate this observation at the histologic level, exfoliated primary incisors were collected from 74 IDM, representing two types of care during gestation and the perinatal period, and from 52 healthy children. The width of the neonatal line was evaluated in the enamel and the dentin by study of bucco-lingual undemineralized sections. Pre- and postnatal enamel was classified according to discolorations, deviations of prisms and hypoplasia. Microradiographic studies included measurements of the neonatal lines and classification of the degree of mineralization in the pre- and postnatal dental hard tissues. Irrespective of treatment, the IDM showed a significantly higher incidence of widened neonatal lines and also an increased frequency of postnatal disturbances compared to the controls. The observations are discussed against the background of the neonatal hypocalcemia reported in IDM.

Amelogenesis Imperfecta↗

Progression of proximal caries in the mixed dentition: a 4-year prospective study.

PURPOSE: The purpose of this study was to investigate the survival rate and median survival time of different stages of proximal caries in 196 children aged 6 to 8 years at baseline examination. METHODS: Proximal caries and its progression were diagnosed from bitewing radiographs taken at 1-year intervals over a period of 4 years. The mesial surface of the first permanent molars, the mesial and distal surfaces of the first and second primary molars, and the distal surface of the primary canine were examined. Sound surfaces, caries lesions in the external- and internal-half of the enamel and external-, middle-, and internal-third of the dentin, as well as filled, extracted, and exfoliated teeth were recorded. A life table analysis was performed to estimate the annual and cumulative survival rates and the median survival time of each state of proximal lesions. RESULTS: For the sound mesial surfaces of the first permanent molars, the cumulative survival rate was 76% and the median survival time was over 48 months. The corresponding values for the external-half of the enamel lesions were 41% and 45 months. Regarding the sound mesial and distal surfaces of the primary teeth, the cumulative survival rate was 92% and the median survival time was over 48 months. The corresponding values for the external and internal-half of the enamel lesions were 40% and 31 months, and 29% and 22 months, respectively. The value of the cumulative survival rate for the external-third of dentin lesions was 42%, with a median survival time of 34 months, and the value for the middle-third of the dentin was 38% with a median survival time of 17 months. CONCLUSIONS: The risk of developing carious lesions in the sound proximal surfaces of both primary teeth and first permanent molars is low during the mixed dentition period; the progression of the external-half of enamel lesions of the first permanent molars is low for the first 3 years and becomes faster thereafter; and as the time period that the tooth exposed to cariogenic factors increases, the progression of the proximal caries is faster for all stages of the lesion in the primary teeth.

Child↗

Caries in primary teeth at 5 and 10 years of age: a longitudinal study.

AIM: This was to explore the caries development in the primary dentition in children aged 5 and later when they were 10, with an emphasis on the caries increment according to type of teeth and surfaces. METHODS: The study was a prospective, longitudinal survey where the children were examined in 1993 when they were 5 years of age (n=217) and re-examined in 1998 when they were 10 (n=186). Caries was examined clinically and with radiographs by calibrated dentists based on a caries diagnostic grading system from 0 to 5. Primary incisors were excluded from the registrations at 10 years of age, while teeth exfoliating during the period were included, based on notes from the dental records. RESULTS: Intra- and inter-examiner reliability ranged from kappa 0.62 to 0.90. Dmfs at 5 years was 5.4 (incisors included) and 7.4 at 10 years (incisors excluded, other exfoliated teeth included). The mean caries increment during the age period showed no significant difference between children with and without caries at 5 years of age. Molar-approximal lesions dominated the increment, and when such lesions were diagnosed at 5 years of age, there was an increased risk for more severe caries (dentine lesions) during the period. CONCLUSION: The caries increment in the primary dentition is considerable for the majority of children during the age period 5-10 years. Even if a risk assessment based on the prevalence of approximal caries at 5 years of age may be useful for deciding individual recall intervals, the results of this study seem to suggest frequent check-ups are needed for the whole population.

Child↗

Absence of adult dental anomalies in familial hypophosphatasia.

This paper is a supplemental report on 3 previous publications about a family in which 3 male children manifested gingival recession, alveolar bone resorption and premature exfoliation of their deciduous teeth without apical root resorption and without clinical signs of inflammation. Laboratory blood and urine studies in conjunction with an analysis of periodontal microflora and family pedigrees established a diagnosis of hypophosphatasia in these 3 children, as well as their father, the paternal grandmother and paternal great-uncle. Clinical data also revealed that a son of the paternal great-uncle and his daughter were similarly affected. The family pedigree is consistent with an autosomal dominant mode of transmission. The 3 brothers are now between the ages of 18 and 22 yr and all have complete permanent dentitions. Aside from some periodontal manifestations of prior dentoalveolar trauma, most of the findings of the periodontal assessment are within normal limits. All 3 exhibit moderate to severe caries and some degree of gingival inflammation, but minimal periodontal pathosis.

Adolescent↗

Progression of approximal caries in relation to iatrogenic preparation damage.

The aim of the present study was to evaluate the effect of iatrogenic preparation damage on the need for operative caries treatment of approximal surfaces, adjacent to Class II amalgam restorations. The material was collected by 77 dentists from the Public Dental Child Health Service in Denmark. It consisted of die-stone models of 187 first-time Class II preparations, adjacent to 190 unfilled approximal surfaces of 58 primary and 132 permanent teeth. The cavity preparations were performed in children between 4 and 17 years of age. They were all filled with amalgam. Information about operative treatment and exfoliation or extraction of the preparation teeth and the adjacent teeth during the following seven years was obtained from the patients' records. Stereomicroscopic examination of the models revealed preparation damage on 64% of the unfilled approximal surfaces in primary teeth and on 69% of the corresponding test surfaces in permanent teeth. During the observation period, operative treatment was performed on 10% of the undamaged test surfaces in primary teeth and on 35% of the damaged ones (p less than 0.05). The corresponding figures for test surfaces in permanent teeth were 6% and 15% (p less than 0.05). It is concluded that iatrogenic preparation damage is a frequent side-effect of operative intervention with approximal caries lesions, and represents a dental health problem, since the damage increases caries progression and the perceived need for restorative therapy of the adjacent teeth.

Adolescent↗

Clinical performance and SEM evaluation of direct composite restorations in primary molars.

PURPOSE: To evaluate the clinical outcome of composite restorations performed in primary molars after 18 months and the morphology of the dentin/resin interface. METHODS: 41 primary molars from children aged 4-9 years were restored with Scotchbond Multi-Purpose Plus adhesive system and Z100 resin-based composite. The restorations were evaluated at baseline, 6, 12 and 18 months using the USPHS method for direct clinical analysis. Plaster models were made at each evaluation period for indirect evaluation. For the morphologic analysis of the dentin/resin interface, seven exfoliated teeth were sectioned longitudinally in a mesio/distal direction and observed in the electro scanning electron microscope. RESULTS: 100% (n = 40) of the restorations evaluated at 6 months were scored as Alpha for anatomical form, color matching, secondary caries, color alteration, and marginal degradation. At 12 months, 96.4% (n = 28) of the restorations received Alpha score and 3.4% Charlie score. At 18 months, all restorations evaluated (27/27) received Alpha score. 23 restorations were indirectly evaluated at 6, 12 and 18 months postoperatively. No significant wear or fractures were observed in any of the restorations. In the evaluation of the dentin/resin interface, the formation of a consistent hybrid layer was observed and the restorations were well adapted to the dentin at 18 months postoperatively.

Acid Etching, Dental↗

Treatment of aggressive periodontitis by osseointegrated dental implants. A case report.

BACKGROUND: Generalized aggressive periodontitis is described as a clinical entity affecting both deciduous and permanent dentition with extensive alveolar bone loss, mobility, and exfoliation of all or many teeth. Controversy exists on dental implant use to restore missing dentition in younger patients. METHODS: This case report presents a patient diagnosed with aggressive periodontitis who has lost all but 4 of her teeth. Her personal and functional desires led us to include implant therapy in her treatment plan. The hematological data are presented with an analysis of the immunological profile. RESULTS: Dental implants were placed, and following 3 months of osseointegration, an implant-supported prosthesis was completed. The patient was followed up for 36 months. CONCLUSIONS: This case report presents an alternative treatment for rehabilitating dentition in a young patient treated for aggressive periodontitis. Similar case studies may help eliminate some of the controversy that exists regarding the use of dental implants in aggressive periodontitis patients.

Adolescent↗

Progression of proximal caries in children with different caries indices: a 4-year radiographic study.

AIM: This was to investigate survival rate, median survival time and differences in the progression of different stages of proximal caries in 196 children, aged 6 to 8 years old, with different caries index at baseline examination. METHODS: Based on DMFS/dmfs values, children were categorized as low, moderate and high caries index groups. Subjects with DMFS/dmfs smaller or equal to half of a child's age were classified as low caries index group, children with DMFS/dmfs greater to half and smaller than or equal to the child's age as moderate, while those with DMFS/dmfs greater than the child's age as high. Proximal caries and its progression were diagnosed from bitewing radiographs taken at 1-year intervals over a period of 4 years. The mesial surface of the first permanent molars, mesial and distal surfaces of the first and second primary molars and distal surfaces of the primary canines were examined. Sound surfaces, caries lesions in the external and internal half of the enamel and external, middle, internal third of the dentine as well as filled, extracted and exfoliated teeth were recorded. STATISTICS: A life table analysis was performed to estimate survival rate and median survival time of each state of proximal caries and differences between the groups in the progression of the proximal lesions were tested with the Wilcoxon pairwise comparison statistic. RESULTS: There were statistically significant differences in the caries rate of the sound proximal surfaces of the primary teeth between the low and high caries index groups. Also, statistically significant differences between these two groups were found in the progression of the external half of the enamel caries in the first permanent molars and in the primary teeth. CONCLUSIONS: A high caries index increases the risk of developing caries in the sound proximal surfaces of posterior primary teeth and causes faster progression of the external half of the enamel lesions in the first permanent molars and posterior primary teeth.

Child↗

Effects of a non-rinse conditioner on the enamel of primary teeth.

The aim of this in vitro study was to evaluate by scanning electron microscopy the morphological aspects of the enamel of primary teeth after etching with 36% phosphoric acid or a non-rinse conditioner. Ten naturally exfoliated anterior primary teeth were selected. The samples were subjected to prophylaxis with pumice paste and water using a low-speed hand piece. Etching was done on the buccal surface. Specimens were divided into 2 groups: G1 (n=10): etching with 36% phosphoric acid gel - Conditioner 36 (Dentsply) for 20 s, followed by water rinse for 15 s; G2 (n=10): etching with NRC - Non Rinse Conditioner (Dentsply) for 20 s, followed by air drying for 15 s. The samples were dehydrated, mounted on metal stubs, coated with gold and observed with Jeol JSM-6100 scanning electron microscope. Electron-micrographic analysis showed that both etching agents were effective for etching the enamel of primary teeth causing the formation of microporosities on the enamel surface, although the etching pattern was more effective with the use of 36% phosphoric acid gel.

Acid Etching, Dental↗