In vitro CO2 9.3-µm short-pulsed laser caries prevention-effects of a newly developed laser irradiation pattern.

Caries prevention with different lasers has been investigated in laboratory studies and clinical pilot trials. Objective of this in vitro study was to assess whether 9.3-µm microsecond short-pulsed CO2 laser irradiation enhances enamel caries resistance without melting, with and without additional fluoride application. Seven groups of enamel, totaling 105 human enamel samples, were irradiated with 2 different carbon dioxide lasers with 2 different energy application systems (original versus spread beam; 9.3 µm wavelength, pulse repetition rate 43 Hz vs 100 Hz, fluence ranges from 1.4 to 3.9 J/cm2, pulse duration 3 µs to 18 µs). The laboratory pH-cycling was performed with or without additional fluoride, followed by cross-sectional microhardness testing. To assess caries inhibition, the mean relative mineral loss delta Z (∆Z) was determined. To evaluate for melting, scanning electron microscopy (SEM) examinations were performed. For the non-laser control groups with additional fluoride use, the relative mineral loss (ΔZ, vol% × µm) ranged between 512 ± 292 and 809 ± 297 (mean ± SD). ΔZ for the laser-irradiated samples with fluoride use ranged between 186 ± 214 and 374 ± 191, averaging a 58% ± 6% mineral loss reduction (ANOVA, P < 0.01 to P < 0.0001). For the non-laser-treated controls without additional fluoride, the mineral loss increased (ΔZ 914 ± 422 to 1224 ± 736). In contrast, the ΔZ for the laser-treated groups without additional fluoride ranged between 463 ± 190 and 594 ± 272 (P < 0.01 to P < 0.001) indicative of 50% ± 2% average reduction in mineral loss. Enhanced caries resistance was achieved by all applied fluences. Using the spread beam resulted in enhanced resistance without enamel melting as seen by SEM. CO2 9.3-µm short-pulsed laser irradiation with both laser beam configurations resulted in highly significant reduction in enamel mineral loss. Modifying the beam to a more homogenous profile will allow enamel caries resistance even without apparent enamel melting.

The evaluation of MTA and Biodentine as a pulpotomy materials for carious exposures in primary teeth.

OBJECTIVE: This study examined the effects of MTA and Biodentine on the clinical and radiographic success rates of pulpotomies performed on primary teeth with carious pulp exposures. MATERIALS AND METHODS: This study was conducted with 44 mandibular primary molars requiring vital pulpotomy. Carious dentin surrounding the exposure site was used as the inclusion criteria for all teeth, which were randomly divided into two groups according to pulpotomy material [MTA group (n = 24), Biodentine group (n = 20)]. Treatment was followed up clinically and radiologically for 24 months. Pulp canal obliteration was not regarded as a failure. RESULTS: Clinical and radiographic success rates at the end of 24 months were 100% for the MTA group and 89.4% for the Biodentine group. Success rates did not vary significantly between the groups (p = 0.646). Pulp canal obliteration was observed in two teeth (8.3%) in the MTA group at 6 months, but the teeth were found to be stabilized by 24 months. CONCLUSION: The long-term clinical and radiographic success rates obtained in this study indicate that both MTA and Biodentine are appropriate options for pulpotomy treatment of primary teeth with carious exposure in patients whose teeth should be retained for long periods of time. CLINICAL RELEVANCE: The etiology of exposure determines pulpal response, making it crucial to distinguish between mechanical and carious exposures. The carious exposure is presumed to be accompanied by severe inflammation, which makes the prognosis of treatment unpredictable. Biomaterials can be used especially in cases with carious pulp exposures.

The Hall Technique and conventional restorative treatment in New Zealand children's primary oral health care - clinical outcomes at two years.

BACKGROUND: New Zealand children's oral health care is mostly provided in primary care oral health clinics. Little is known about treatment outcomes. HYPOTHESIS/AIM: To investigate different treatment outcomes of primary molar carious lesions in a sample of children in primary care. DESIGN: Quasi-experimental study of 180 5- to 8-year-old children. Each child had one carious primary molar treated by a dental therapist with a plastic restorative material (PRM) or a pre-formed stainless steel crown placed with the Hall Technique (HT). After 2 years, restorative outcomes were categorised as success, minor failure, or major failure. Data were analysed using Chi-square tests. RESULTS: A total of 147 (82%) children were followed up; mean follow-up period 25 months (range: 21-35 months). Failure was observed significantly more in the PRM group (32%) than the HT group (6%). When baseline carious lesions were radiographically deep with marginal ridge breakdown (MRB), there was a higher proportion of major failures than when they were shallow without MRB (33% and 1%, respectively; P < 0.001). Among the deep lesions, those treated with the HT showed better success than PRM. CONCLUSIONS: There was a much higher success rate in the children treated with HT than PRM. Deep carious lesions responded better to HT than PRM.

Endodontic treatment.

The Finnish guideline on endodontics emphasizes good quality of endodontic treatment and coronal seal of the restoration. For prevention of endodontic treatment need caries control is essential. For deep carious lesions stepwise excavation or partial caries removal are recommended. Partial pulpotomy can be used if bleeding can be controlled. The decision for root canal treatment is based on prognosis, occlusion and general health of the patient. The use of kofferdam is essential in aseptic working. Chemomechanical preparation with NaOCI and root canal filling within 0-2 mm from the apex improve prognosis. Healing should be controlled annually up to four years.

An evidence-based review of dental matrix systems.

The restoration of proximal surface cavities, originating from Class II carious lesions, to "normal" anatomical specifications is a fundamental objective for the dental practitioner. Cognitive interpretation of tooth morphology attained from evidence-based resources, together with the necessary psychomotor skills for correct design and completion, are considered essential strategies for restoration success. Also, the visualization of the original tooth structure, if present, should substantially benefit the dentist in the creation of a clinically satisfactory restoration. The purpose of this evidence-based review is to define the cause and effect of decisions based on optimum treatment standards of care for the patient. The concepts of form and function, as related to the oral environment, and the consequences of unsatisfactory dental restorative care will be scrutinized. This article will identify and explain the different challenges and solutions for restoration of dental proximal lesions and provide an overview of past, present, and future procedures.

Effect of a CO2 Laser on the Inhibition of Root Surface Caries Adjacent to Restorations of Glass Ionomer Cement or Composite Resin: An In Vitro Study.

This study investigated the effect of CO2 laser irradiation on the inhibition of secondary caries on root surfaces adjacent to glass ionomer cement (GIC) or composite resin (CR) restorations. 40 dental blocks were divided into 4 groups: G1 (negative control): cavity preparation + adhesive restoration with CR; G2: (positive control) cavity preparation + GIC restoration; G3: equal to group 1 + CO2 laser with 6 J/cm(2); G4: equal to group 2 + CO2 laser. The blocks were submitted to thermal and pH cycling. Dental demineralization around restorations was quantified using microhardness analyses and Light-Induced Fluorescence (QLF). The groups showed no significant differences in mineral loss at depths between 20 µm and 40 µm. At 60 µm, G2 and G3 ≠ G1, but G4 = G1, G2 and G3. At 80 µm, G4 ≠ G1, and at 100 µm, G4 = G2 = G1. At 140 and 220 µm, G2, G3, and G4 = G1. The averages obtained using QFL in groups 1, 2, 3, and 4 were 0.637, 0.162, 0.095, and 0.048, respectively. QLF and microhardness analyses showed that CO2 laser irradiation reduced mineral loss around the CR restorations but that it did not increase the anticariogenic effect of GIC restorations.

Clinical outcomes of indirect composite restorations for grossly mutilated primary molars: a clinical observation.

This study was conducted to report the clinical outcomes and the parental and child satisfaction of onlays for restoring mutilated primary molars. Twenty subjects, ages 3-8 years, with the presence of at least 1 mutilated primary molar (≥3 carious surfaces and a carious surface area ≥3/4 of the occlusal surface) were recruited. This study assessed the clinical success, gingival health, and parent/child satisfaction of 28 indirect composite onlays. The onlays showed a 100% retention rate at 12 months follow-up and a marginal integrity of 96.43%. High rates of satisfactory Alpha ratings for color stability (92.86%), surface texture (92.86%), and anatomic form (100%), coupled with significant improvements in gingival health of the restored teeth (P < 0.05), were reported. Indirect composite onlays successfully restored anatomic form and function of the grossly decayed primary molars--with shorter chairside times--while satisfying the esthetic demands of the young pediatric patients.

Effect of mineral trioxide aggregate and formocresol pulpotomy on vital primary teeth: a clinical and radiographic study.

BACKGROUND: Pulpotomy is the common therapy for cariously exposed pulps in symptom-free primary molar teeth. Formocresol (FC) is considered the gold standard dressing agent for pulpotomy, but concerns have been raised over the years about its safety. Other alternative pulpotomy agents have been investigated and suggested. OBJECTIVE: The objective was to evaluate and compare the clinical and radiographic response of FC and white mineral trioxide aggregate (MTA) as pulpotomy materials on primary molars. MATERIALS AND METHODS: Fifty primary molars, with deep carious lesion that exposed a vital but asymptomatic pulp, in 37 children aged 4-7 years were treated with conventional pulpotomy procedure. The teeth were divided randomly into two groups. Group I (FC) and group II (MTA). The treated teeth were evaluated clinically and radiographically and were followed-up for 12 months. RESULTS: At the end of the 12 months follow-up, the clinical success rates for FC and MTA were 81% and 100%, respectively. There was a statistically significant difference ( P = 0.04) between the clinical success rates of FC and MTA. While the radiographic success rates for FC and MTA were 81% and 96%, respectively, there was no statistically significant difference between the radiographic success of MTA and FC. CONCLUSION: White MTA showed a higher clinical and radiographic success rate when compared to FC as a pulpotomy agent in vital primary molars, and it has a potential to become a replacement for FC in primary molars.

Dental extractions using improvised equipment.

Extracting a tooth is the final treatment for multiple dental problems. Persons who are not dentists, however, have little experience with tooth extractions. When a remote setting makes it impossible to send a patient for optimal dental treatment, the clinician may need to extract teeth, sometimes using improvised equipment. The following cases of two patients with three carious, painful molars describe such a situation. The non-dental clinicians had to improvise not only appropriate dental tools, but also personal protective equipment, a functional suction machine, medications for a dental block, a dental chair, and dental consent forms and follow-up instructions in the patients' language. In these cases, they also communicated with their patients through a translator. To prepare to do tooth extractions in remote settings, clinicians should learn and practice dental blocks and review extraction techniques before they deploy. If they must do an extraction, clinicians should use the closest approximation available to the appropriate dental tools. When done correctly, a dental extraction can take some time and should not be rushed.

[Medical exchange between faculty of medicine, university of the Ryukyus and Laos country. Medical support with a cleft lip and palate treatment].

The Faculty of Medicine, University of the Ryukyus, started a "Public Health Project in Lao P.D.R.", which is one of the JICA projects, in 1992, and has been carrying out the "Sethathirath Hospital Improvement Project" since 1999 to improve medical treatment and health care in Lao P.D.R. Marked progress has been made. In addition, the projects of "Medical support for cleft lip and palate patients" performed by both the Oral and Maxillofacial Surgery Department of the University of the Ryukyus Hospital and Okinawa-Laos Cleft Lip and Palate Support Center have continued since 2001. So far, 231 cleft lip and palate patients have benefited from these projects, and favorable effects of medical education and technology transfer for medical staff in Laos have been obtained. Furthermore, during the 3-year period of another JICA project, called "From tooth brushing to oral health--Oral care education for Laos children", the dental caries rate of children in Donkoi Elementary School in Laos reduced from 92.5 to 61.8%, showing a decrease of 30.7%. Based on these encouraging results, in 2012, the JICA started a larger partnership project named 'Cha-ganzyu', which is from the dialect of Okinawa meaning health forever, focusing on oral health improvement of school children and local people of Laos.

Outcome of Partial Pulpotomy in Immature Permanent Teeth with Symptomatic Irreversible Pulpitis: A Prospective Case Series Assessment.

INTRODUCTION: The aim of this prospective case series was to assess the clinical and radiographic outcome of partial pulpotomy in caries-exposed symptomatic, vital, immature, permanent molars. METHODS: Thirty-four immature molars with deep caries and symptoms of irreversible pulpitis were treated by partial pulpotomy and ProRoot MTA as a capping material. After complete caries removal, the inflamed part of the pulp was removed. Complete hemostasis was achieved using a sterile cotton pellet moist initially with sodium hypochlorite 1.5% and then with sterile saline. ProRoot MTA (Dentsply Sirona, Charlotte, NC) was placed as a capping material onto the remaining pulp tissue. The cavity was sealed using a light-curing resin-modified Ca(OH)2 cavity liner, and patients were referred to a pediatric dentist for permanent restoration. Descriptive statistics and cross tabulations were performed including variables examined before, during, and after the procedure. RESULTS: All examined teeth presented a favorable clinical and radiographic outcome with normal periapical tissues, complete apical closure, and formation of a dentinal bridge beneath the capping material. Signs of partial pulp chamber calcification were only detected in 2 cases. Postoperatively, most patients did not report any pain (23/34, 67.7%), whereas the rest reported minor intensity pain (11/34, 32.3) and the use of analgesic or anti-inflammatory drugs only for 1 day (10/34, 29.4%). CONCLUSIONS: Partial pulpotomy seems to provide a universally successful outcome when managing symptomatic vital immature teeth with no signs of complications and completion of apical closure. It could be a viable treatment of choice in cases of caries-exposed vital immature teeth with symptoms of irreversible pulpitis.

Should compromised first permanent molar teeth in children be routinely removed? A health economics analysis.

OBJECTIVE: To evaluate the cost-effectiveness of retaining one or more compromised first permanent molars (cFPMs) affected by dental caries or enamel hypomineralization, compared to timely extraction, in children aged 8 years. METHODS: A Markov model was developed to simulate the lifetime of a cFPM. Two management strategies were compared: extraction facilitating spontaneous space closure or maintenance of teeth with restorations. Ten health states were utilized to capture long-term outcomes including various tooth restorations, prostheses or a retained gap at the cFPM site. Outcomes were expressed as Quality Adjusted Tooth-Years (QATYs). The model was informed by survey data on patient preferences for treatment outcomes and UK data on costs. Discounted costs and QATYs were calculated over 62 years. RESULTS: Regardless of the number of cFPMs, retaining cFPMs was more effective than early removal, generating an additional 2.3 QATYs per cFPM. Early removal of one or two cFPM under general anaesthetic (GA) was more expensive than retention and hence never cost-effective. Retaining a cFPM was more expensive than early removal under local anaesthesia or where four cFPMs were extracted under GA. In these cases, retaining cFPMs was cost-effective if a QATY was valued at £100 or £35, respectively. Results were robust to sensitivity analysis. CONCLUSION: Preserving a cFPM was more cost-effective than the early loss of one, or two cFPMs under GA. Preservation of four cFPMs was cost-effective if sufficient value was placed on a QATY. These findings can guide clinical practice on management of cFPMs alongside patient/payer values on maintaining teeth.

What has been the United Kingdom's experience with retention of third molars?

BACKGROUND: In 2000, the first National Institute of Clinical Excellence (NICE) guidelines related to third molar (M3) surgery, a commonly performed operation in the United Kingdom, were published. This followed research publications and professional guidelines in the 1990 s that advised against prophylactic surgery and provided specific therapeutic indications for M3 surgery. The aim of the present report was to summarize the available evidence on the effects of guidelines on M3 surgery within the United Kingdom. MATERIALS AND METHODS: Data from primary care dental services and hospital admissions in England and Wales during a 20-year period (Hospital Episode Statistics 1989/1990 to 2009/2010), and from private medical insurance companies were analyzed. The volume and, where possible, the nature of the M3 surgery activity over time were assessed together, as were the collateral effects of the guidelines, including patient age at surgery and the indications for surgery. RESULTS: The volume of M3 removal decreased in all sectors during the 1990 s before the introduction of the NICE guidelines. During the 20-year period, the proportion of impacted M3 surgery decreased from 80% to 50% of admitted hospital cases. Furthermore, an increase occurred in the mean age for surgical admissions from 25.5 to 31.8 years. The change in age correlated with a change in the indications for M3 surgery during that period, with a reduction in "impaction," but an increase in "caries" and "pericoronitis" as etiologic factors, in accordance with the NICE guidelines. CONCLUSION: The significant decrease in M3 surgery activity occurred before the NICE guidelines. Thus, M3 surgery has been performed at a later age, with indications for surgery increasingly in accordance with the NICE guidelines. The importance of clinical monitoring of the retained M3s is discussed.

Pulp chamber access alternative in pulpectomies in a child with Wolff-Parkinson-White syndrome. A case report.

BACKGROUND: Wolff-Parkinson-White syndrome is a congenital abnormality of the heart. Patients with this syndrome and multiple dental caries with pulp exposure may require comprehensive dental treatment under general anesthesia. Pulpectomy is performed in primary teeth with pulp expose. This treatment in anterior teeth requires palatal access and the majority there is no good visibility, requiring more time to perform. Therefore, this case aimed to demonstrate a pulp chamber opening alternative in pulpectomies in a child with Wolff-Parkinson-White syndrome. CASE PRESENTATION: A 3-year-old female patient with Wolff-Parkinson-White syndrome and multiple dental caries with reversible pulpitis in anterior upper teeth. The dental treatment was performed under general anesthesia. Due to abundant hemorrhage in anterior upper teeth, pulpectomies were performed, which pulp chamber openings were modified by labial and the treatment itself was completed. After, these teeth were rehabilitated with direct restorative veneers using light-curing composite resin. The follow-up at 12 months showed an absence of evidence clinic and radiographic. CONCLUSION: This case demonstrated the pulp chamber opening performed by labial in pulpectomy is an effective and viable alternative to reduce operative time and improve visibility in pulpotomies in a child with Wolff-Parkinson-White syndrome.

Reorienting a paediatric oral health service towards prevention: lessons from a qualitative study of dental professionals.

ISSUE ADDRESSED: Reorienting primary care dental services towards prevention is a priority for improving the oral health of Australian children with extensive dental caries. We explored the attitudes and beliefs of dental staff about the factors that helped or hindered the establishment and implementation of a hospital-based parent counselling program to manage existing, and prevent new, carious lesions in children. A further aim was to explore the influence of the program on the hospital's reorientation to prevention. METHODS: Eight of nine program staff participated in two focus group interviews, and two co-ordinating staff participated in semi-structured interviews. Interviews were audio-recorded and transcribed. Interview recordings and transcripts were analysed by qualitative thematic analysis. RESULTS: The participants identified a number of factors that they felt influenced the establishment and implementation of the program, including the dental team's support of the initiative, the advantages of building on existing clinic infrastructure and procedures, the utility of harnessing dental assistants as a resource for oral health promotion, and the confidence of dental professionals to provide parent counselling. CONCLUSION: Efforts to establish a preventive program in a public paediatric dental service should ensure that all members of the dental team are engaged during all phases of the program, that dental assistants are trained and supported to deliver parent counselling, and that interprofessional partnerships with services such as dietetics are fostered.

Oral surgery in a child with a prosthetic aortic valve and pulmonary artery stent at risk for thromboembolism.

Children with prosthetic cardiac valves and other invasive mechanical devices that direct blood flow require anticoagulant medication for prevention of thrombosis. Dental surgery for these children has historically consisted of decreasing and/or discontinuing the oral anticoagulant and instituting heparin therapy prior to the planned dental procedure, which can result in thromboembolism and increased morbidity and mortality. This case report demonstrates that oral anticoagulation need not be decreased or discontinued prior to extraction of multiple carious primary teeth in a child at risk for thromboembolism.

Five-year Clinical Evaluation of a Nanofilled and a Nanohybrid Composite in Class IV Cavities.

The purpose of this study was to evaluate a nanofilled and a nanohybrid composite, in combination with manufacturer-recommended etch-and-rinse adhesives, in class IV cavities. Thirty-four patients aged 14-46 years (mean age, 27.1 years) comprised the study group. Twenty-six patients received two class IV restorations and eight patients received four class IV restorations. For each patient, half the number of restorations were performed using a nanohybrid composite (Ceram X duo) and the remaining half used a nanofilled resin composite (Filtek Supreme XT), with two- (XP Bond) and three-step (Scotchbond Multipurpose) etch-and-rinse adhesives, respectively. Two experienced examiners evaluated the restorations for retention, color match, marginal discoloration, wear/loss of anatomic form, caries formation, marginal adaptation, and surface texture to compare the baseline (after placement) and annual recalls over 5 years. The cumulative success rates for the Filtek Supreme XT and Ceram X duo restorations after five years were 86.2% and 89.7%, respectively. Four Filtek Supreme XT and three Ceram X duo restorations failed. There was no statistically significant difference between the nanofilled and nanohybrid composites at any of the evaluation periods for any of the parameters evaluated. Despite the limited number of restorations, all restorations were clinically acceptable regarding retention, color match, marginal discoloration, wear or loss of anatomic form, the formation of caries, marginal adaptation, and surface texture, except the failed restorations. Fracture was the main cause of restoration failure.

Accessing and restoring root caries: a case report.

Adequate access to root caries can be problematic. The inability to view, isolate, and access the entire lesion may result in residual caries, poor adaptation of the restoration, and defective margins. Minor periodontal procedures, ranging from a mini-flap involving only one tooth, to conventional flap surgery can provide increased visibility and access to these troublesome areas. Through utilization of this technique, excellent preparations and restorations can be achieved. Restorative materials with a high potential for fluoride release as well as uptake should be highly considered in cases of root caries. The selection of a conventional or resin-modified glass ionomer provides several advantages. Most notably are the ability of these restoratives to chemically bond to tooth structure, and to provide significant fluoride release and uptake. These properties are not present in amalgam, composites, or compomers. Additionally, the material itself is relatively easy to use and provides an effective zone of caries inhibition around the margins of the restoration. Glass ionomers are not as sensitive to moisture as conventional resin composites or compomers, and, as a result, may provide a better bond to tooth structure and margination in areas where moisture control is troublesome. Finally, the polymerization shrinkage of these materials is not as great as resin composites, which should also improve marginal integrity. Clinical studies have demonstrated longevity of ten years or greater as well as success in xerostomic patients. Management of xerostomic patients should be directed toward finding satisfactory methods to relieve dryness. Some prescription medications are available, but should only be recommended after consultation with the primary care physician. Oral moisturizers are also available as are saliva substitutes. Caution should be used when recommending saliva substitutes due to the fact that some commercial products have been demonstrated to have a pH below the demineralization point of enamel. Products of this nature should be avoided. In the last few decades, the age of the patient population has increased and individuals have a greater tendency to maintain their natural dentition throughout their entire life. Gingival recession and subsequent root exposure has become more prevalent in the adult population. Additionally, the use of prescription medications that impact the flow and consistency of saliva is widespread. As a result of these phenomena, it has been predicted that root caries will become more prevalent. When preventive measures prove to be ineffective and restorations must be placed, access, visibility, and appropriate material selection are paramount. A combined minor periodontal surgery and restorative procedure is relatively simple, and when done properly, can provide excellent and affordable dentistry in these problematic areas.

Remote Dental Surgery as a Medical Civilian Assistance Program (MEDCAP): Helping Iraqi, Kurdish, and U.S. Forces Win Hearts and Minds in the Fight Against Daesh.

Dr Ferreira discusses the work of the Humanitarian Aid and Security Forces (HASF) in providing volunteer dental services to a local Christian militia in Mosul, Iraq.

No additional benefit of using a calcium hydroxide liner during stepwise caries removal: A randomized clinical trial.

BACKGROUND: Clinicians often use calcium hydroxide liners during stepwise treatment of advanced caries. In this randomized clinical trial, the authors compared the short-term outcome of stepwise caries removal with and without use of a calcium hydroxide liner in conjunction with provisional resin-modified glass ionomer (RMGI) restorations. METHODS: The authors included in the trial 98 patients aged 15 to 30 years who had a deep carious lesion in a posterior tooth. The authors measured the dentin thickness radiographically and recorded its color, consistency, and moisture, as well as the bacterial count of the lesions. After partial caries removal, the authors assigned patients randomly to have their caries provisionally restored using RMGI with (control group) or without (test group) a calcium hydroxide liner. The primary outcome measure was tooth vitality after 90 days. Secondary outcomes included changes in dentinal, radiographic, and microbiological characteristics of the lesions. RESULTS: The authors found no statistically significant difference between the test and control groups in tooth vitality after 90 days. Irrespective of calcium hydroxide liner use, the authors observed darker, harder, drier, and less contaminated dentin after the provisional restorations, but dentin thickness remained unchanged. CONCLUSIONS: On the basis of this 3-month clinical trial's results, the use of a calcium hydroxide liner during stepwise caries excavation and provisional restoration did not provide any additional benefit. PRACTICAL IMPLICATIONS: After 3 months, using a calcium hydroxide liner does not appear to offer any additional benefit when clinicians use RMGI provisional restorations during stepwise caries removal. Longer studies are needed to confirm these results.