BDNF rs6265 Genotype Influences Outcomes of Pharmacotherapy and Subthalamic Nucleus Deep Brain Stimulation in Early-Stage Parkinson's Disease.

INTRODUCTION: The efficacy of pharmacotherapy and deep brain stimulation of the subthalamic nucleus in treating Parkinson's disease motor symptoms is highly variable and may be influenced by patient genotype. The relatively common (prevalence about one in three) and protein-altering rs6265 single nucleotide polymorphism (C > T) in the gene BDNF has been associated with different clinical outcomes with levodopa. OBJECTIVE: We sought to replicate this reported association in early-stage Parkinson's disease subjects and to examine whether a difference in clinical outcomes was present with subthalamic nucleus deep brain stimulation. MATERIALS AND METHODS: Fifteen deep brain stimulation and 13 medical therapy subjects were followed for 24 months as part of the Vanderbilt DBS in Early Stage PD clinical trial (NCT00282152, FDA IDE #G050016). Primary outcome measures were the Unified Parkinson's Disease Rating Scale (UPDRS) and Parkinson's Disease Questionnaire-39. RESULTS: Outcomes with drug therapy in subjects carrying the rs6265 T allele were significantly worse following 12 months of treatment compared to C/C subjects (UPDRS: +20 points, p = 0.019; PDQ-39: +16 points, p = 0.018). In contrast, rs6265 genotype had no effect on overall motor response to subthalamic nucleus deep brain stimulation at any time point; further, rs6265 C/C subjects treated with stimulation were associated with worse UPDRS part II scores at 24 months compared to medical therapy. CONCLUSIONS: Genotyping for the rs6265 polymorphism may be useful for predicting long-term response to drug therapy and counseling Parkinson's disease patients regarding whether to consider earlier subthalamic nucleus deep brain stimulation. Validation in a larger cohort of early-stage Parkinson's disease subjects is warranted.

Subthalamic Nucleus Deep Brain Stimulation Alters Prefrontal Correlates of Emotion Induction.

OBJECTIVES: Deep brain stimulation (DBS) of the subthalamic nucleus (STN) improves motor symptoms in advanced Parkinson's disease. STN DBS may also affect emotion, possibly by impacting a parallel limbic cortico-striatal circuit. The objective of this study was to investigate changes in prefrontal cortical activity related to DBS during an emotion induction task. MATERIALS AND METHODS: We used near infrared spectroscopy to monitor prefrontal cortex hemodynamic changes during an emotion induction task. Seven DBS patients were tested sequentially in the stimulation-on and stimulation-off states while on dopaminergic medication. Patients watched a series of positive, negative, and neutral videos. The general linear model was used to compare prefrontal oxygenated hemoglobin concentration between DBS states. RESULTS: Deep brain stimulation was correlated with prefrontal oxygenated hemoglobin changes relative to the stimulation off state in response to both positive and negative videos. These changes were specific to emotional stimuli and were not seen during neutral stimuli. CONCLUSIONS: These results suggest that STN stimulation influences the prefrontal cortical representation of positive and negative emotion induction.

Neck Pain and Cervical Dystonia: Treatment Outcomes from CD PROBE (Cervical Dystonia Patient Registry for Observation of OnabotulinumtoxinA Efficacy).

BACKGROUND: Pain is a prevailing feature of cervical dystonia (CD), the most common form of focal dystonia. This analysis examined pain relief after onabotulinumtoxinA treatment in CD subjects with moderate/severe pain from the Cervical Dystonia Patient Registry for Observation of OnabotulinumtoxinA Efficacy (CD PROBE). METHODS: CD PROBE was a prospective, multicenter, observational registry of CD subjects who were naïve to botulinum toxin (BoNT), new to physician, or had not received BoNT within ≥ 16 weeks if in a clinical trial. Subjects were eligible for 3 treatments, with variable session intervals. Descriptive and inferential statistics were utilized to evaluate the change in pain scores in the population with moderate/severe neck pain at baseline (Pain Numeric Rating Scale [PNRS] score 4 to 10). RESULTS: Of 1046 enrolled, 733 (70.7%) had moderate/severe neck pain at baseline. Postinjection pain questionnaire responses 4 to 6 weeks after each of the 3 treatments revealed that a majority of subjects (67.1%, 72.4%, and 76.4%) reported pain relief; mean time to pain relief was 7.1, 7.4, and 7.6 days. All pain scales showed significant improvements from baseline to final visit (all P < 0.0001): PNRS, mean 6.6 to 3.8; CD Impact Profile-58 Pain and Discomfort subscale, mean 78.7 to 56.5; and Toronto Western Spasmodic Torticollis Rating Scale Pain subscale, mean 12.6 to 8.5. Multivariable regression models showed that initial pain score significantly contributed to the final pain score for all scales. CONCLUSION: Results from this real-world clinical registry indicate that a majority of CD subjects with moderate/severe neck pain experience significant relief following onabotulinumtoxinA treatment.

Osteogenic potential of laser modified and conditioned titanium zirconium surfaces.

STATEMENT OF PROBLEM: The osseointegration of dental implant is related to their composition and surface treatment. Titanium zirconium (TiZr) has been introduced as an alternative to the commercially pure titanium and its alloys as dental implant material, which is attributed to its superior mechanical and biological properties. Surface treatments of TiZr have been introduced to enhance their osseointegration ability; however, reliable, easy to use surface modification technique has not been established. PURPOSE: The purpose of this study was to evaluate and compare the effect of neodymium-doped yttrium aluminum garnet (Nd-YAG) laser surface treatment of TiZr implant alloy on their osteogenic potential. MATERIALS AND METHODS: Twenty disc-shaped samples of 5 mm diameter and 2 mm height were milled from the TiZr alloy ingot. The polished discs were ultrasonically cleaned in distilled water. Ten samples each were randomly selected as Group A control samples and Group B consisted of Nd-YAG laser surface etched and conditioned test samples. These were evaluated for cellular response. Cellular adhesion and proliferation were quantified, and the results were statistically analyzed using nonparametric analysis. Cellular morphology was observed using electron and epiflurosence microscopy. RESULTS: Nd-YAG laser surface modified and conditioned TiZr samples increased the osteogenic potential. CONCLUSION: Nd-YAG laser surface modification of TiZr, improves the cellular activity, surface roughness, and wettability, thereby increasing the osteogenic potential.

Deep brain stimulation in early stage Parkinson's disease: operative experience from a prospective randomised clinical trial.

BACKGROUND: Recent evidence suggests that deep brain stimulation of the subthalamic nucleus (STN-DBS) may have a disease modifying effect in early Parkinson's disease (PD). A randomised, prospective study is underway to determine whether STN-DBS in early PD is safe and tolerable. OBJECTIVES/METHODS: 15 of 30 early PD patients were randomised to receive STN-DBS implants in an institutional review board approved protocol. Operative technique, location of DBS leads and perioperative adverse events are reported. Active contact used for stimulation in these patients was compared with 47 advanced PD patients undergoing an identical procedure by the same surgeon. RESULTS: 14 of the 15 patients did not sustain any long term (>3 months) complications from the surgery. One subject suffered a stroke resulting in mild cognitive changes and slight right arm and face weakness. The average optimal contact used in symptomatic treatment of early PD patients was: anterior -1.1±1.7 mm, lateral 10.7±1.7 mm and superior -3.3±2.5 mm (anterior and posterior commissure coordinates). This location is statistically no different (0.77 mm, p>0.05) than the optimal contact used in the treatment of 47 advanced PD patients. CONCLUSIONS: The perioperative adverse events in this trial of subjects with early stage PD are comparable with those reported for STN-DBS in advanced PD. The active contact position used in early PD is not significantly different from that used in late stage disease. This is the first report of the operative experience from a randomised, surgical versus best medical therapy trial for the early treatment of PD.

Potential subjects' responses to an ethics questionnaire in a phase I study of deep brain stimulation in early Parkinson's disease.

BACKGROUND: Central to ethically justified clinical trial design is the need for an informed consent process responsive to how potential subjects actually comprehend study participation, especially study goals, risks, and potential benefits. This will be particularly challenging when studying deep brain stimulation and whether it impedes symptom progression in Parkinson's disease, since potential subjects will be Parkinson's patients for whom deep brain stimulation will likely have therapeutic value in the future as their disease progresses. METHOD: As part of an expanded informed consent process for a pilot Phase I study of deep brain stimulation in early stage Parkinson's disease, an ethics questionnaire composed of 13 open-ended questions was distributed to potential subjects. The questionnaire was designed to guide potential subjects in thinking about their potential participation. RESULTS: While the purpose of the study (safety and tolerability) was extensively presented during the informed consent process, in returned responses 70 percent focused on effectiveness and 91 percent included personal benefit as poten- tial benefit from enrolling. However, 91 percent also indicated helping other Parkinson's patients as motivation when considering whether or not to enroll. CONCLUSIONS: This combination of responses highlights two issues to which investigators need to pay close attention in future trial designs: (1) how, and in what ways, informed consent processes reinforce potential subjects' preconceived understandings of benefit, and (2) that potential subjects see themselves as part of a community of Parkinson's sufferers with responsibilities extending beyond self-interest. More importantly, it invites speculation that a different paradigm for informed consent may be needed.

Subthalamic nucleus neuronal firing rate increases with Parkinson's disease progression.

Parkinson's disease is a neurodegenerative disorder characterized by progressive loss of dopaminergic cells in the central nervous system, in particular the substantia nigra, resulting in an unrelenting loss of motor and nonmotor function. Animal models of Parkinson's disease reveal hyperactive neurons in the subthalamic nucleus that have increased firing rates and bursting activity compared with controls. Although subthalamic nucleus activity has been characterized in patients with advanced-stage Parkinson's disease, it has not been described in patients with early-stage Parkinson's disease. Here we present the results of subthalamic nucleus neuronal recordings from patients with early-stage Parkinson's disease (Hoehn and Yahr stage II) enrolled in an ongoing clinical trial compared with recordings from age- and sex-matched patients with advanced Parkinson's disease. Subthalamic nucleus neurons had a significantly lower firing rate in early versus advanced Parkinson's disease (28.7 vs 36.3 Hz; P<.01). The overall activity of the subthalamic nucleus was also significantly lower in early versus late Parkinson's disease, as measured by background neuronal noise (12.4 vs 14.0 mV; P<.05). No significant difference was identified between groups in the bursting or variability of neuronal firing in the subthalamic nucleus, as measured by a burst index or the interspike interval coefficient of variability. The results suggest that neuronal firing in the subthalamic nucleus increases with Parkinson's disease progression.

Rationale and design of a prospective study: Cervical Dystonia Patient Registry for Observation of OnaBotulinumtoxinA Efficacy (CD PROBE).

BACKGROUND: A registry of patients with cervical dystonia (Cervical Dystonia Patient Registry for Observation of onaBotulinumtoxinA Efficacy [CD PROBE]) was initiated to capture data regarding physician practices and patient outcomes with onabotulinumtoxinA (BOTOX®, Allergan, Inc., Irvine, CA, USA). Methods and baseline demographics from an interim analysis are provided. METHODS/DESIGN: This is a prospective, multicenter, clinical registry in the United States enrolling subjects with cervical dystonia (CD) who are toxin naïve and/or new to the physicians' practices, or who had been in a clinical trial but received their last injection ≥ 16 weeks prior to enrollment. Subjects are followed over 3 injection cycles of onabotulinumtoxinA, with assessments at time of injection and 4-6 weeks later. Information on physician's practice, patient demographics, CD disease history, duration of treatment intervals and neurotoxin dose, dilution, use of electromyography, and muscles injected are collected. Outcomes are assessed by physicians and subjects using various questionnaires. DISCUSSION: This ongoing registry includes 609 subjects with the following baseline data: 75.9% female, 93.6% Caucasian, mean age 57.6 ± 14.3, age at symptom onset 48.3 ± 16.2, and time to diagnosis 5.4 ± 8.6 years, with an additional 1.0 ± 3.5 years before treatment. Of those employed at the time of diagnosis, 36.6% stopped working as a result of CD. CD PROBE, the largest clinical registry of CD treatment, will provide useful data on current treatment practices with onabotulinumtoxinA, potentially leading to refinements for optimization of outcomes. TRIAL REGISTRATION: NCT00836017.

Deep brain stimulation for early-stage Parkinson's disease: an illustrative case.

OBJECTIVES: Subthalamic nucleus (STN) deep brain stimulation (DBS) is an effective intervention in advanced Parkinson's disease (PD), but its efficacy and safety in early PD are unknown. We are conducting a randomized pilot trial investigating DBS in early PD. This report describes one participant who received bilateral STN-DBS. MATERIALS AND METHODS: Thirty subjects have been randomized to either optimal drug therapy (ODT) or DBS + ODT. Microelectrode recordings from the STN and substantia nigra are collected at implantation. The Unified Parkinson's Disease Rating Scale Motor Subscale (UPDRS-III) is administered in the ON and OFF states semi-annually and neuropsychological function and quality of life are assessed annually. We describe a 54-year-old man with a two-year history of PD who was randomized to DBS + ODT and followed for two years. RESULTS: The subject showed a lower STN to substantia nigra ratio of neuronal activity than advanced PD patients, and higher firing rate than non-PD patients. The subject's total UPDRS and UPDRS-III scores improved during the two-year follow-up, while his OFF UPDRS-III score and levodopa equivalent daily dose increased. Quality of life, verbal fluency, and verbal learning improved. He did not experience any serious adverse events. CONCLUSIONS: This report details the first successful application of bilateral STN-DBS for early-stage PD during a clinical trial.

Spasticity treatment facilitates direct care delivery for adults with profound intellectual disability.

Many adults with intellectual disabilities (ID) have spasticity, where increased muscle tone impairs activities of daily living (ADL) self-performance and care delivery. There are few reports of spasticity treatment for people with ID, and none of functionally meaningful outcomes. Our objective is to determine the effect of comprehensive spasticity management on ADL self-performance and care delivery. Baseline evaluation included repeated modified Ashworth and range of motion assessments, and timed and videotaped care task observations. Spasticity treatment was initiated immediately thereafter. Follow-up evaluation was conducted after spasticity management was optimized, one year after initiation. All individuals with spasticity at a single developmental center for whom treatment goals could be identified were included. Treatment was recommended by a neurologist from any accepted treatment for spasticity except oral medications, including botulinum neurotoxin A, intrathecal baclofen and orthopedic procedures. The main outcome measure is comparison of ease of videotaped care delivery, rated by direct caregivers blinded to participant treatment status. Spasticity treatment resulted in significant improvement across all outcome measures. Range of motion improved by 9 degrees (P = 0.005) and MAS by 0.4 (P = 0.022). Participants took 14% percent less time to complete tasks post-treatment (P = 0.01). Thirteen caregivers completed evaluations of 35 video pairs with an intra-class correlation of 0.9. After treatment, undergarment change (P = 0.031) and shirt change (P = 0.017) were rated easier, and all goals (P = 0.0006). Transfers trended toward improvement (P = 0.053). This study shows comprehensive spasticity management provides meaningful improvement in ADL care for patients with ID, which may improve quality of life and reduce caregiver burden.

Clustering of dystonia in some pedigrees with autosomal dominant essential tremor suggests the existence of a distinct subtype of essential tremor.

BACKGROUND: There is an ongoing debate whether essential tremor (ET) represents a monosymptomatic disorder or other neurologic symptoms are compatible with the diagnosis of ET. Many patients with clinically definite ET develop dystonia. It remains unknown whether tremor associated with dystonia represent a subtype of ET. We hypothesized that ET with dystonia represents a distinct subtype of ET. METHODS: We studied patients diagnosed with familial ET and dystonia. We included only those patients whose first-degree relatives met diagnostic criteria for ET or dystonia with tremor. This cohort was ascertained for the presence of focal, segmental, multifocal, hemidystonia or generalized dystonia, and ET. RESULTS: We included 463 patients from 97 kindreds with autosomal dominant mode of inheritance (AD), defined by the vertical transmission of the disease. ET was the predominant phenotype in every ascertained family and each was phenotypically classified as AD ET. "Pure" ET was present in 365 individuals. Focal or segmental dystonia was present in 98 of the 463 patients; 87 of the 98 patients had ET associated with dystonia, one had dystonic tremor and ten had isolated dystonia. The age of onset and tremor severity did not differ between patients with "pure" ET and ET associated with dystonia. We did not observe a random distribution of dystonia in AD ET pedigrees and all patients with dystonia associated with ET were clustered in 28% of all included pedigrees (27/97, p < 0.001). CONCLUSIONS: Our results suggest that familial ET associated with dystonia may represent a distinct subtype of ET.

BDNF rs6265 Variant Alters Outcomes with Levodopa in Early-Stage Parkinson's Disease.

Disease outcomes are heterogeneous in Parkinson's disease and may be predicted by gene variants. This study investigated if the BDNF rs6265 single nucleotide polymorphism (SNP) is associated with differential outcomes with specific pharmacotherapy treatment strategies in the "NIH Exploratory Trials in PD Long-term Study 1" (NET-PD LS-1, n = 540). DNA samples were genotyped for the rs6265 SNP and others (rs11030094, rs10501087, rs1491850, rs908867, and rs1157659). The primary measures were the Unified Parkinson's Disease Rating Scale (UPDRS) and its motor component (UPDRS-III). Groups were divided by genotype and treatment regimen (levodopa monotherapy vs levodopa with other medications vs no levodopa). T allele carriers were associated with worse UPDRS outcomes compared to C/C subjects when treated with levodopa monotherapy (+ 6 points, p = 0.02) and to T allele carriers treated with no levodopa treatment strategies (UPDRS: + 8 points, p = 0.01; UPDRS-III: + 6 points, p = 0.01). Similar effects of worse outcomes associated with levodopa monotherapy were observed in the BDNF rs11030094, rs10501087, and rs1491850 SNPs. This study suggests the levodopa monotherapy strategy is associated with worse disease outcomes in BDNF rs6265 T carriers. Pending prospective validation, BDNF variants may be precision medicine factors to consider for symptomatic treatment decisions for early-stage PD patients.

Positive family history of essential tremor influences the motor phenotype of Parkinson's disease.

Previous reports have suggested that essential tremor (ET) represents a risk factor for the development of Parkinson's disease (PD). Patients with long-standing ET who develop PD tend to have a tremor-dominant subtype. To further clarify this association, we examined patients from kindreds with autosomal dominant ET who had signs of isolated PD but did not meet criteria for overlapping ET. We identified 22 patients with PD meeting these diagnostic criteria, and 90% (20 of 22) had tremor-predominant subtype of PD. Unilateral rest tremor was the presenting symptom in 15 of 22 patients, bradykinesia or rigidity in 5 of 22, and gait problems in 2 of 22. Postural tremor was relatively mild, and the severity of kinetic tremor tightly correlated with rest tremor (r = 0.83, P < 0.001). Tremor-dominant subtype of PD in patients with a positive family history of ET suggests that these patients have inherited a genetic susceptibility factor for tremor, which affects the motor phenotype of PD.

Testing for HIV-1 infection in a public developmental center.

The discovery of human immunodeficiency virus type 1 (HIV) infection in an individual who recently moved from a developmental center prompted the center to offer HIV testing to current and former residents. The guardians of 199 (93 percent) of the Center's current residents consented to testing. The remaining 14 current residents (seven percent) were not tested because informed consent for testing was not received. Consent for testing of 41 former residents was also obtained. All people who underwent testing were seronegative. Whether former residents who were not included in the present analysis received testing from other sources is not known.

Comparison of botulinum neurotoxin preparations for the treatment of cervical dystonia.

BACKGROUND: Comparative studies of botulinum neurotoxin preparations to date have generally examined 2 preparations at prespecified dose ratios in relatively homogeneous groups of patients under controlled study conditions. It is unclear whether the differences in adverse-event rates that have been noted under these controlled conditions can be generalized to the broader population of cervical dystonia patients, who are treated with a wider range of doses in a variety of settings. OBJECTIVE: We conducted a systematic review and analysis of the published literature to compare rates of dysphagia and dry mouth in studies of botulinum neurotoxin products. METHODS: We searched the MEDLINE, EMBASE, Biosis, SciSearch, JICST (Japan Science and Technology Center), and Pascal databases from 1985 through 2006 using the terms cervical dystonia, spasmodic torticollis, and botulinum toxin for original English-language studies of Botox, Dysport, or Myobloc in the treatment of cervical dystonia (or spasmodic torticollis) that documented adverse events by treatment or patient. Studies that involved patients with various types of dystonias or movement disorders were included as long as adverse events were reported separately for those with cervical dystonia. Rates of dysphagia with the original preparation of Botox were considered separately from those with the current preparation of Botox. RESULTS: Seventy published articles were included in the analysis (30 Botox, 24 Dysport, 3 Botox + Dysport, 11 Myobloc, 2 Botox + Myobloc). Mean total doses per treatment ranged from 60 to 374 U for Botox, 125 to 1200 U for Dysport, and 579 to 19,853 U for Myobloc. Botox was associated with a significantly lower rate of dysphagia than Dysport, with mean dysphagia rates of 10.5% for original Botox, 8.9% for current Botox, and 26.8% for Dysport (both, P < 0.05). Myobloc was associated with dry mouth (3.2%-90.0%) in 9 of 13 studies, but this adverse event was not reported in a sufficient number of studies of botulinum toxin type A preparations (Botox, n = 2; Dysport, n = 6) to permit statistical comparison. In the weighted analysis, the duration of effect differed between botulinum neurotoxin products (current Botox > Myobloc > original Botox > Dysport; all, P < 0.001), but only 43 (61.4%) of the 70 studies reported duration, and the definitions varied. CONCLUSION: The results of this analysis indicate differences in adverse-event rates between botulinum neurotoxin preparations, suggesting that use of these products should be based on their individual dosing, efficacy, and safety profiles.

Thalamotomy, DBS-Vim, and DBS-GPi for generalized dystonia: a case report.

Generalized dystonia is a disabling disorder that can severely affect quality of life. Pharmacological treatment is unsatisfactory, and surgical therapy has been the focus for symptom improvement. We present the first case report of a patient with disabling generalized dystonia treated with a thalamotomy and deep brain stimulation of the thalamus and globus pallidus (DBS-Vim, DBS-GPi). His tremor and dystonic symptoms have dramatically improved through combining these surgical interventions.

Difficulty in securing treatment for degenerative hip disease in a patient with Down syndrome: the gap remains open.

In 2002, the office of the U.S. surgeon general published a report detailing the discrepancies between the quality of healthcare afforded to persons with and without mental retardation. This article examines the case of a female resident of a developmental center with profound mental retardation due to Down syndrome and degenerative hip disease. Although she was in urgent need of a total hip replacement, the operation was denied or delayed by several different surgeons. Using a survey of physician attitudes, we examine several possible motivations behind the surgeons' reluctance to perform the procedure and conclude that these reasons were not appropriate in this case. Finally, we reiterate the surgeon general's call to eradicate preconceptions held in the medical community about the population of persons with mental retardation that result in similar failures to provide adequate care.

Depression and intelligence in patients with Parkinson's disease and deep-brain stimulation.

The goal of this study is to examine the association of depression with intelligence and education in patients with Parkinson's disease treated with bilateral subthalamic nucleus stimulation (STN-DBS). The literature has been contradictory concerning depression in Parkinson's disease patients. Some studies have shown less depression in Parkinson's disease patients with more education not treated with STN-DBS. Other recently published studies indicate that STN-DBS improves the depression associated with Parkinson's disease. No studies have examined the correlation of these factors with depression in Parkinson's disease patients treated with STN-DBS. We administered the Beck Depression Inventory (BDI) pre- and postoperatively to 21 Parkinson's disease patients (seven women, 14 men, ages 49-75) who underwent STN-DBS. The postoperative scores of the lower 50th percentile (n=8) of the Verbal Comprehensive Index of the Wechsler Adult Intelligence Scale (WAIS-III) decreased significantly (P=0.036), while the upper 50th percentile (n=13) remained nearly constant (P=0.802). Furthermore, as the education increased from highschool to graduate level, patients demonstrated less improvement in depressive symptoms postoperatively. These findings suggest that Parkinson's disease patients with lower intelligence test scores and less education benefit more with regards to depressive symptomatology after STN-DBS than patients with higher scores and education.

The cost of medical education in an ambulatory neurology clinic.

Decreased revenue from clinical services has required academic hospitals and physicians to improve productivity. Medical student education may be a significant hindrance to increased productivity and income. This study quantifies the amount of time spent by faculty members teaching medical students in an ambulatory neurology clinic as well as the amount of time students occupied rooms when seeing patients on their own. Over a three-week period in an ambulatory neurology clinic, an observer noted these quantities of time, and the opportunity costs of both amounts of time were determined. Attending physicians spent an average of 19.6 minutes per medical student per half-day teaching, which translates to an average cost of $20.78 per half-day clinic. Students spent an average of 49.9 minutes per half-day seeing patients in the absence of an attending physician, an opportunity cost to the clinic of $142.50 per student per half-day.

Antibacterial efficacy and effect of Morinda citrifolia L. mixed with irreversible hydrocolloid for dental impressions: A randomized controlled trial.

AIM: This study aimed to evaluate whether the extract of Morinda citrifolia L. mixed with irreversible hydrocolloid powder decreases microbial contamination during impression making without affecting the resulting casts. MATERIALS AND METHODS: Twenty volunteers were randomly divided into two groups (n = 10). Group A 30 ml extract of M. citrifolia L diluted in 30 ml of water was mixed to make the impression with irreversible hydrocolloid material. Group B 30 ml deionized water was mixed with irreversible hydrocolloid material to make the impressions following which the surface roughness and dimensional stability of casts were evaluated. RESULTS: Extract of M. citrifolia L. mixed with irreversible hydrocolloid decreased the percentage of microorganisms when compared with water (P < 0.001) but did not affect the surface quality or dimensional stability of the casts. CONCLUSION: Mixing the extract of M. citrifolia L. with irreversible hydrocolloid powder is an alternative method to prevent contamination without sacrificing impression quality.