Peter Bottenberg

Development and testing of bioadhesive, fluoride-containing slow-release tablets for oral use.

Abstract— The bioadhesive characteristics of tablets for oral use made from modified starch, polyacrylic acid (PAA), polyethylene glycol (PEG) and sodium carboxymethylcellulose (CMC) were investigated. Adhesion force and energy were determined in‐vitro and maximal adhesion time was evaluated in‐vivo in human subjects. In‐vitro, PAA showed the best bioadhesive properties, followed by modified maize starch and PEG with a mol. wt of 300 000–400 000 daltons. The presence of 0·1 mg of fluoride as NaF did not lead to significant differences in adhesion force and energy for the same formulation. The in‐vivo bioadhesion was not strongly correlated to the in‐vitro data. PAA, despite its excellent adhesion, proved to be irritating to the mucosa. PEG with a mol. wt of 200000 daltons was subject to erosion. CMC showed good bioadhesive properties but the mechanical strength of the tablets was low. Modified maize starch tablets containing 5% (w/w) PAA and PEG with a mol. wt of 300 000 daltons proved to be the most suitable formulations for a fluoride‐slow‐release tablet with bioadhesive properties. In‐vitro, the tablets released all of the fluoride within the 8 h period, with a high initial release. The release rate was related to the water absorption rate of the tablets. The PAA‐containing formulations and the CMC formulations had the fastest release. In‐vivo, fluoride levels with a minimum of 150 and a maximum of 1000 μg mL−1 were maintained for 8 h in the oral cavity. These fluoride levels were sustained significantly longer than those obtained with the administration of fourfold the amount of fluoride in the form of a fluoride‐containing toothpaste. The release characteristics in‐vivo exhibited a high variation. The use of bioadhesive polymers in oral pharmacotherapy seems promising.

A prospective randomized clinical trial of one bis-GMA-based and two ormocer-based composite restorative systems in class II cavities: five-year results

OBJECTIVESnOrmocer composites, consisting of a silicon-based polymer, have been developed recently as a tooth-colored restorative material. The purpose of this prospective randomized clinical trial was to evaluate the performance of two small-particle hybrid ormocer-based restorative systems (AD, Admira/Admira Bond, VOCO; DE, Definite/Etch & Prime 3.0, Dentsply) and one small-particle hybrid bis-GMA-based composite restorative system (TC, Tetric-Ceram/Syntac, Ivoclar-Vivadent) in class II cavities.nnnMETHODSnFrom 128 occlusal-proximal restorations (44 AD, 43 DE and 41 TC) placed in 32 adult patients, eventually 77 (22 AD, 29 DE and 26 TC) remained available for evaluation after 5 years. Their clinical performance was scored according to the USPHS criteria and evaluation of bite-wing radiographs.nnnRESULTSnAfter 5 years, eight AD, six DE and seven TC restorations had failed (p=0.10, log-rank test). The main reason was fracture or marginal gap formation, while secondary caries accounted for four failures. In all restorations the quality of surface, margins and contact point decreased significantly compared to baseline. DE had a significant poorer color match (p<0.01). Statistical evaluation using the KW test showed that failures were concentrated on specific patients.nnnCONCLUSIONSnIn a group of class II restorations, there was no significant difference in failures after 5 years between ormocer-based and bis-GMA-based restorative systems.

Prevalence and Determinants of Enamel Fluorosis in Flemish Schoolchildren

As part of an epidemiological study on the oral health of Flemish schoolchildren, fluoride use was studied together with risk factors (medical history, tap water fluoride concentration, use of fluoride supplements, toothpaste and brushing habits). Fluorosis was scored according to the Thylstrup-Fejerskov index (TFI) in children aged 11 years (4,128 children examined). Explanatory variables were recorded yearly, starting at the age of 7. Earliest toothpaste use was reported at the age of 1. By age 7, 99.7% of the children reported the use of toothpaste (90% fluoride-containing), but only 13.9% reported using a pea-sized amount. At age 7, 66% of the children had received systemic fluoride supplements during at least part of their childhood. At 11 years, 92% of the children used a fluoride-containing toothpaste and 6% still received systemic fluoride supplements. Fluorosis was present in about 10% of all the children examined, mainly TFI score 1 (7.3% in upper central incisors). Logistic regression established tooth brushing frequency and fluoride supplement use, in addition to tap water fluoride concentrations above 0.7 mg/l, as significant risk factors when the presence of fluorosis on at least one tooth was used as outcome variable. Children having fluorosis had a lower risk of caries, both in the primary (median dmft 1, range 0–10 vs. 2, range 0–12) and permanent dentition (median DMFT 0, range 0–5 vs. 0, range 0–11).

Clinical observations and success rates of palatal implants

INTRODUCTIONnAnchorage control is a challenge in orthodontics. Implants can be used to provide absolute anchorage.The aim of this study was to evaluate the success rates of palatal implants used for various anchorage purposes.nnnMETHODSnThirty-four palatal implants were placed in 33 patients. In the adults (n = 9), the implants (n = 9) were placed in the median palatal suture. In the adolescents (n = 24), the implants (n = 25) were placed in the paramedian region. The implants were used to support a transpalatal arch, a modified distal jet appliance, or a modified hyrax screw. An implant was considered successful if it could be used as planned throughout the orthodontic treatment. The patients were asked to evaluate their pain perception after placement and explantation procedures.nnnRESULTSnThree implants failed early (during the waiting period before orthodontic loading, within 3 months after placement). During the orthodontic loading period, no implants were lost. No statistically significant correlations were found between success rate and sex, age, primary stability, placement site (median or paramedian), implant size, or palatal depth. Pain perception after surgery was acceptable. The success rate of the palatal implants in this study was 91%.nnnCONCLUSIONSnPalatal implants are a reliable method of providing absolute anchorage control in a variety of patients for different indications. They can be loaded both directly and indirectly.

In vivo use of a dual acid etch biopsy for the evaluation of lead profiles in human surface enamel.

Two successive acid etch biopsies were performed on the permanent maxillary right central incisors of two age-groups of children resident in an urban area in Belgium. Lead was determined in the biopsy solutions and the concentrations were related to etch depths which were calculated from the calcium and phosphorus concentrations in the biopsy solutions. The mean lead concentration of the first enamel biopsy layer was five times higher than in the second biopsy layer. A strong relation was observed between the two biopsies. It was shown that calibration of the lead values with respect to etch depths and Ca/P ratios was desirable and that a robust regression analysis approach was needed instead of classic least-squares regression analysis. However, the second biopsy provided more reliable lead estimates. In this study no increase in lead concentration in surface enamel could be demonstrated with age. Therefore, it was concluded that for these children the presence of lead in surface enamel had to be attributed primarily to preeruptive uptake.

Knowledge of Flemish paediatricians about children's oral health – results of a survey

Objective: To examine the knowledge paediatricians have about oral health in children.

Comparison of salivary fluoride concentrations after administration of a bioadhesive slow‐release tablet and a conventional fluoride tablet

Abstract— The in‐vitro and in‐vivo fluoride release of bioadhesive, slow‐release tablets prepared from a mixture of polyethylene glycol polymers, containing 0·1 mg of fluoride as NaF was studied, and their ability to sustain fluoride levels in saliva were compared with conventional fluoride tablets with the same fluoride content. In‐vitro release experiments showed that the bioadhesive tablets needed 8 h to release all their fluoride compared with < 1 h for the conventional fluoride tablets. In‐vivo, the bioadhesive tablets had a retention period of 6 h and could sustain a salivary fluoride level of more than 10 μm above the baseline for 7 h. The conventional fluoride tablets achieved a peak concentration of 0·5 Mm directly after dissolution in the mouth, but the fluoride level could not be sustained for longer than 1 h. A good agreement was found between the in‐vitro swelling behaviour of the bioadhesive tablets and their in‐vitro and in‐vivo release characteristics and their in‐vivo retention time.

In Vivo Intracanal Temperature Evolution during Endodontic Treatment after the Injection of Room Temperature or Preheated Sodium Hypochlorite

INTRODUCTIONnHeating a sodium hypochlorite solution improves its effectiveness. The aim of this study was to measure the in vivo temperature changes of sodium hypochlorite solutions that were initially preheated to 66°C or at room temperature inside root canals during routine irrigation.nnnMETHODSnThirty-five root canals were prepared to ISO size 40 with 4% taper. A type K (nickel-chromium-nickel) thermocouple microprobe (Testo NV, Ternat, Belgium) was positioned within 3 mm of the working length to measure the temperature at 1-second intervals. In each canal, 2 test protocols were evaluated in a randomized order with 3% sodium hypochlorite solutions: (1) preheated to 66°C and (2) at room temperature. The temperature measurements began 5 seconds before the 25 seconds of irrigant injections and continued for 240 seconds. This resulted in 270 data points for each protocol.nnnRESULTSnThe temperature of the irrigant at room temperature increased from the initial intracanal temperature after injection of 20.7°C (±1.2°C) to 30.9°C (±1.3°C) in 10 seconds and to 35°C (±0.9°C) after 240 seconds. The temperature of the preheated to 66°C solution decreased from 56.4°C (±2.7°C) to 45.4°C (±3.0°C) after 5 seconds, reached 37°C (±0.9°C) after 60 seconds, and reached 35.7°C (±0.8°C) after 240 seconds.nnnCONCLUSIONSnThe original temperatures of the sodium hypochlorite solutions were buffered inside the root canal and tended to rapidly evolve to equilibrium. The findings of this study contribute to an improved understanding of the thermodynamic behaviors of irrigant solutions inside root canals in vivo.

Efficacy of three different pulpotomy agents in primary molars: a randomized control trial

AIMnTo compare the clinical and radiographic efficacy of Biodentine™ , ProRoot® White Mineral Trioxide Aggregate (WMTA) and Tempophore™ as pulpotomy medicaments in the treatment of carious primary molars.nnnMETHODOLOGYnA parallel-design, randomized controlled trial was developed. Patients above 3xa0years of age with carious primary teeth with vital pulps without spontaneous pain or history of swelling were included. Fifty-eight patients (82 teeth) with a mean age of 4.79xa0±xa01.23xa0years were included. The teeth were randomized, blinded and allocated to one of the three groups (Biodentine™ , ProRoot® WMTA or Tempophore™ ) for pulpotomy treatment. All teeth were followed up clinically and radiographically (after 6, 12 and 18xa0months) by two blinded calibrated investigators. A generalized estimating equationxa0(GEE), Wald chi-square test and an intention-to-treat analysis (ITT) with last carried forward approach were performed using Statistical Package for Social Sciences vxa021.0 (IBM Corp., Armonk, NK, USA).nnnRESULTSnForty-six patients and 69 teeth were available for follow-up after 18xa0months. Clinical success (radiographic success in parenthesis) was 95.24% (94.4%), 100% (90.9%) and 95.65% (82.4%) in the Biodentine™ , ProRoot® WMTA and Tempophore™ groups, respectively, but the difference was not significant. Pulp canal obliteration was significantly different amongst the experimental groups as the Biodentine™ group exhibited significantly more pulp canal obliteration when compared to the ProRoot® WMTA group at 6xa0months (Pxa0=xa00.008) and 18xa0months (Pxa0=xa00.003).nnnCONCLUSIONSnAfter 18-month follow-up, there was no significant difference between Biodentine™ in comparison with ProRoot® WMTA or Tempophore™ .

Fluoride content of mineral waters on the Belgian market and a case report of fluorosis induced by mineral water use

Fluorosis can be caused by mineral waters with an elevated fluoride content which is not always correctly mentioned on the label. The present study was undertaken in order to explain the origin of fluorosis in an 8-year-old Caucasian female patient who presented with small white spots on her primary teeth and lower permanent incisors, consistant with fluorosis degree 3 (Fig. 1) [6]. Tooth-brushing with a pea-sized amount of ‘children’s toothpaste’ was reported from 8 months onwards; no fluoride supplements were administered. This could not have contributed to fluorosis. Further questioning revealed that she received infant formula with mineral water ‘‘Aurèle Cristalline’’ early in childhood. Since some mineral waters have an elevated fluoride content, a bottle of this particular brand was analysed for fluoride and found to contain 1.23 mg/l of fluoride (Table 1) without a mentioning on the label. Fluoride intakes could be calculated at an age of 8 weeks (0.082 mg/kg), 3 months (0.19 mg/kg), 6 months (0.18 mg/kg) and 12 months (0.13 mg/kg). The level of ‘safe’ fluoride intake of 0.1 mg/kg [2] was exceeded from the 3rd month onwards. In order to evaluate whether other brands presented the same problem, mineral waters, fruit juices and soft drinks were obtained (Table 1). Carbonated waters and drinks were degassed prior to analysis by stirring for 1 h. Three 50 ml samples (45 ml of drink together with 5 ml TISAB III, Merck, Darmstadt, Germany) were prepared from each brand and electrochemically assessed for fluoride [4]. If undeclared fluoride levels above 1 mg/l were found or levels varied more than 10% from the declared value, a second bottle was analysed. Fluoride concentrations were not always correctly displayed on the label (Table 1). Fluorosis as a well-known side-effect of caries-preventive fluoride administration has been mainly attributed to a (combined) intake of fluoridated tap water, toothpaste and systemic fluoride supplements [1]. In several countries, consumption of tap water is in regression and bottled (mineral) water is consumed instead [5]. Mineral waters can contain elevated levels of fluoride which can vary between different bottles of the same brand [4]. In the case of inadvertent use of highly mineralised water or unawareness of the fluoride content due to incomplete labelling, this can increase the risk for fluorosis and other health problems [3]. Preparation of infant formula with fluoride-containing tap or mineral water can cause fluorosis even in the primary dentition if administration starts early [2], as shown here. Heavily mineralised water of the Vichy sources is known to cause fluorosis of not only the dentition [3] but also of the skeleton. The fluoride content of ‘‘ice-tea’’ (0.7 mg/l) could be due to the tea extract and that of fruit juices and soft drinks can be explained by naturally occurring fluoride in tap water used for their preparation. Fluoride content of mineral waters above 1.0 mg/l increases the risk of fluorosis, especially in cases of