Composite Replacement of Amalgam Restoration Versus Freshly Cut Dentin: An In Vitro Microleakage Comparison.

OBJECTIVE: The aim of this study was to evaluate the microleakage of the composite restorations when bonded to tooth structure previously restored with amalgam material compared with that of freshly cut dentin. METHODS AND MATERIALS: Thirty intact, extracted intact human molars were mounted in autopolymerizing acrylic resin. Class II box preparations were prepared on the occluso-proximal surfaces of each tooth (4-mm bucco-lingual width and 2-mm mesio-distal depth) with the gingival cavosurface margin 1 mm above the CEJ. Each cavity was then restored using high copper amalgam restoration (Disperalloy, Dentsply) and then thermocycled for 10,000 thermal cycles. Twenty-five of the amalgam restorations were then carefully removed and replaced with Filtek Supreme Ultra Universal (3M ESPE); the remaining five were used for scanning electron microscopy and energy dispersive x-ray spectroscopy analysis. A preparation of the same dimensions was performed on the opposite surface of the tooth and restored with composite resin and thermocycled for 5000 thermal cycles. Twenty samples were randomly selected for dye penetration testing using silver nitrate staining to detect the microleakage. The specimens were analyzed with a stereomicroscope at a magnification of 20×. All of the measurements were done in micrometers; two readings were taken for each cavity at the occlusal and proximal margins. Two measurements were taken using a 0-3 scale and the percentage measurements. RESULTS: Corrosion products were not detected in either group (fresh cut dentin and teeth previously restored with amalgam). No statistically significant difference was found between the microleakage of the two groups using a 0-3 scale at the occlusal margins (McNemar test, p=0.727) or proximal margins (Wilcoxon signed-rank test, p=0.174). No significance difference was found between the two groups using the percentage measurements and a Wilcoxon signed-rank test at either the occlusal (p=0.675) or proximal (p=0.513) margins. However, marginal microleakage was statistically significant between the proximal and occlusal margins (p<0.001). CONCLUSION: Within the limitations of this in vitro study, no significant difference was found between the microleakage of nondiscolored dentin in teeth that were previously restored with amalgam compared with freshly cut dentin. However, marginal microleakage in the proximal surface was higher than that in the occlusal surface.

Success criteria in implant dentistry: a systematic review.

The purpose of this study was to examine the most frequently used criteria to define treatment success in implant dentistry. An electronic MEDLINE/PubMED search was conducted to identify randomized controlled trials and prospective studies reporting on outcomes of implant dentistry. Only studies conducted with roughened surface implants and at least five-year follow-up were included. Data were analyzed for success at the implant level, peri-implant soft tissue, prosthetics, and patient satisfaction. Most frequently reported criteria for success at the implant level were mobility, pain, radiolucency, and peri-implant bone loss (> 1.5 mm), and for success at the peri-implant soft-tissue level, suppuration, and bleeding. The criteria for success at the prosthetic level were the occurrence of technical complications/prosthetic maintenance, adequate function, and esthetics during the five-year period. The criteria at patient satisfaction level were discomfort and paresthesia, satisfaction with appearance, and ability to chew/taste. Success in implant dentistry should ideally evaluate a long-term primary outcome of an implant-prosthetic complex as a whole.

Deuterated gamma-malonic acid: its neutron crystal structure in relationship to other polymorphs of aliphatic dicarboxylic acids.

Three complete neutron diffraction datasets have been collected for deuterated malonic acid single crystals, DOOC(CD(2))COOD, above (153 K), just below (56 K) and further below (50 K) the low-temperature phase transition (T(c) = 57 K). The structural details obtained for this transition, studied previously solely by spectroscopic and calorimetric techniques, clearly establish its first-order nature. At 153 K, the space group is P\bar 1, Z = 2, Z' = 1. The molecules are packed as linear chains linked end-to-end by asymmetric hydrogen bonds so that the carboxyl groups form cyclic dimers. The deuterons in the carboxyl links are ordered. Neighboring chains are cross-linked through C-D...O hydrogen bonds. Upon cooling through the transition the cell doubles along the a axis. Molecules which are equivalent by symmetry above T(c) become independent below T(c) owing to conformational changes in alternate chains. At 50 K, the space group is P\bar 1, Z = 4, Z' = 2. Thermal motion analysis, using for all three temperatures the same segmented rigid-body model, reveals a large torsional motion around the one COOD group associated with the conformational change. Refinements were carried out on all three datasets with an anharmonic structural model, including higher-order displacement tensors (Gram-Charlier expansion up to fourth order). Only atoms involved in torsional motion exhibit a significant anharmonic component which increases with temperature.

Optical phenomenon of peri-implant soft tissue. Part II. Preferred implant neck color to improve soft tissue esthetics.

OBJECTIVES: The purpose of this study was to investigate an optical solution to eliminate the undesirable shine-through effect of implants on peri-implant mucosa by selecting an optimized implant neck color based on an objective and quantifiable method. MATERIAL AND METHODS: The optical effect of color strips on 15 peri-implant mucosal sites of 14 patients with Straumann single-tooth implant replacements in the maxillary anterior region was analyzed. The color differences between the peri-implant mucosa with insertion of each of eight different color strips (white, black, light pink, pink, light orange, orange, gold, violet) and the gingiva of an adjacent or contralateral tooth without any color strips were compared for the selection of optimal color of implant neck. Spectrophotometric color measurements were performed to compare the color difference index (DeltaE) and color coordinates (DeltaL*, Deltaa*, Deltab* and DeltaC*). RESULTS: The colors of the peri-implant mucosa with color strips and the gingiva of natural tooth demonstrated that the test site soft tissue with color strips of light pink, pink, light orange and orange showed a significantly smaller DeltaE value (P<0.05). Moreover, light pink exhibited the lowest mean DeltaE value of 2.6+/-0.6, indicating a clinically indistinguishable color difference. CONCLUSIONS: The results suggest that it is possible to improve gingival esthetics by coloring the implant neck, most effectively with light pink, to mask the impact of the underlying titanium implant. The use of implants with optimized neck colors to correct an esthetic deficiency may be a feasible approach to establish improved peri-implant soft tissue esthetics.

Stress and inflammation as a detrimental combination for peri-implant bone loss.

The causes of peri-implant bone loss continue to be controversial. To determine the impact of biomechanical stress and inflammation, we investigated a total of 80 interforaminal implants in situ for more than 10 years. Two stress groups, with 14 patients each, were established: a low-stress situation with single-standing implants, and an increased-stress situation with splinted implants. To categorize inflammation, we introduced a Composite Inflammation Score using 4 inflammatory parameters. Peri-implant bone loss was calculated from digital panoramic radiographs. To differentiate between the effects of stress and inflammation, we compared bone loss in both stress groups at equivalent levels of inflammation. With greater Composite Inflammation Score values, a clear discrepancy between single-standing and splinted implants was evident (p = 0.117/0.000, regression analysis; p = 0.135/0.000, analysis of variance; p = 0.002, t tests). While stress and inflammation alone may not necessarily be detrimental factors, the presence of stress heightens peri-implant bone loss significantly as inflammation increases.

A time-dependent healing function for immediate loaded implants.

Current interest in immediate dental implant loading has grown due to a number of clinical advantages this treatment modality offers. To obtain a deeper insight into the changing mechanical properties during the healing phase, results from removal torque tests are used in a biomechanical model. The ultimate removal torques, which depend on healing time, are described by a time-dependent healing function. The bone behavior is modeled using an elastic law with damage. The evolution of damage is represented with an incremental equation with an initial damage value and two material parameters. The nonlinear relationship between the torque and the angle of rotation up to the ultimate torque can be calculated. By changing the elastic parameter in the elastic damage law, the remodeling process can be characterized. In a further step, the elastic parameters and the limits for shear stress from the biomechanical model for the removal torque will be used in an FE analysis in order to obtain information on the axial loading limits of a dental implant at different healing times.

Iron-silica interaction at extreme conditions and the electrically conducting layer at the base of Earth's mantle.

The boundary between the Earth's metallic core and its silicate mantle is characterized by strong lateral heterogeneity and sharp changes in density, seismic wave velocities, electrical conductivity and chemical composition. To investigate the composition and properties of the lowermost mantle, an understanding of the chemical reactions that take place between liquid iron and the complex Mg-Fe-Si-Al-oxides of the Earth's lower mantle is first required. Here we present a study of the interaction between iron and silica (SiO2) in electrically and laser-heated diamond anvil cells. In a multianvil apparatus at pressures up to 140 GPa and temperatures over 3,800 K we simulate conditions down to the core-mantle boundary. At high temperature and pressures below 40 GPa, iron and silica react to form iron oxide and an iron-silicon alloy, with up to 5 wt% silicon. At pressures of 85-140 GPa, however, iron and SiO2 do not react and iron-silicon alloys dissociate into almost pure iron and a CsCl-structured (B2) FeSi compound. Our experiments suggest that a metallic silicon-rich B2 phase, produced at the core-mantle boundary (owing to reactions between iron and silicate), could accumulate at the boundary between the mantle and core and explain the anomalously high electrical conductivity of this region.

Overdenture attachment selection and the loading of implant and denture-bearing area. Part 1: In vivo verification of stereolithographic model.

Preliminary to a study investigating the force transfer from osseointegrated dental implants to the surrounding bone via various types of overdenture attachment, a stereolithographic model (SL-model) was constructed and compared to an in vivo situation in order to confirm the validity of the modeling technique for the planned measurements of implant strain and denture-bearing area loading. The SL-model was generated using the patient's computer tomographic data and duplicated in a material of known elastic properties. The model was fitted with sensors to measure strains in the peri-implant bone and loading forces within the posterior mandibular bone, i.e. the denture-bearing area of the mandible. Special telescopic copings were constructed to measure implant strain in this model as well as in vivo. Using these copings under identical overdenture loading conditions, the strains measured at the implants in vivo and in vitro were the same and never exceeded a tolerance of two standard deviations or a mean difference of -8.5% of the in vitro value. This indicates that the model was reliable for the measurement of implant strain. Denture-bearing area loading within the alveolar ridge cannot be measured in vivo. Instead, a method of extrapolating in vivo denture-bearing area loading figures from implant strain readings was developed and tested (better than 90% accuracy). These in vivo extrapolated figures were then compared to in vitro readings under otherwise identical loading conditions. The result indicated that the SL-model is reliable for measurements of denture-bearing area loading with an error of 10 to 20%.

Overdenture attachment selection and the loading of implant and denture-bearing area. Part 2: A methodical study using five types of attachment.

In general, an implant is loaded via axial and horizontal forces. Besides this, moment loading can also occur. The aim of this study was to investigate how different prosthetic connectors with overdentures develop force transfer to implant and bone as well as to the denture-bearing alveolar ridge. Five connectors were investigated on a stereolithographic model fabricated according to a real patient situation. The model was fitted with strain gauges on the "bone" distal and medial to the implants and with vertical force transducers in the alveolar "bone" under the denture-bearing area. The parallel-sided rigid telescopic connector developed the highest moment loading of the implant (P<0.001), which would suggest restraint in the use of this connector. The bar construction also showed somewhat high moments but these may have been at least partly exaggerated by the individual patient situation. Loading results through the non-rigid telescopic copings, single spherical attachments and magnet overdentures demonstrated a low level of implant moment loading which would in part result from horizontal forces caused by denture forward shift during force application. The denture-bearing area loading was different with all attachments (P<0.001) and was related to the rigidity of the connector and reached the highest values with the non-rigid telescopic coping. The clinical implications of the various findings are discussed.

Comparative in vitro study of tissue welding using a 808 nm diode laser and a Ho:YAG laser.

In vitro porcine arteries and veins have been welded end-to-end using either a 808 nm diode laser combined with an indocyanine green enhanced albumin solder, or with a continuous-wave (cw) Ho:YAG laser without biological solder. The vascular stumps were approached to each other over a coronary dilatation catheter in order to obtain a precise alignment and good coaptation. Standard histology revealed for both welding techniques lateral tissue damage between 2 and 3 mm caused by laser-induced heat. Good solder attachment to the tissue was observed by the use of a scanning electron microscope. The vessels soldered with the 808 nm diode laser using albumin solder showed considerably higher tensile strength (1 N compared to 0.3 N) than vessels welded exclusively by Ho:YAG laser radiation. In contrast, leaking pressure (350 +/- 200 mmHg) and bursting pressure (457 +/- 200 mmHg) were found to be independent of the welding technique used. This study demonstrates that fast (total welding time about 2-5 min), stable and tight microvascular anastomosis can be achieved with the use of a dye-enhanced albumin laser soldering technique and an ancillary coronary dilatation catheter.

Connective tissue orientation around dental implants in a canine model.

The objective of this study was to evaluate the orientation of collagen in the canine gingival connective tissue to a titanium surface (TI), and to hydroxyapatite coatings applied by plasma-spraying (HAPS) and ion beam assisted deposition (IBAD), on the supracrestal region of dental implants after 3 and 4 months. The effects of induced peri-implantitis on the soft connective tissue apposed to the implant were also evaluated. The use of these three surface types allowed for the evaluation of the effects of chemical composition (TI vs. IBAD; same topography) and topography (HAPS vs. IBAD; similar chemical composition) on the collagen fiber orientation. The majority of collagen fibers were found to be parallel to the implant surface, and there was no significant effect of surface type on orientation. There was a significant effect of inflammation on the connective tissue attachment length. The loss of bone height and concomitant gingival recession reduced the length of soft connective tissue apposed to the implant zone designed for collagen fiber attachment.

Temporal backward projection of optoacoustic pressure transients using fourier transform methods.

In medical imaging different techniques have been developed to gain information from inside a tissue. Optoacoustics is a method to generate tomography pictures of tissue using Q-switched laser pulses. Due to thermal and pressure confinement, a short light pulse generates a pressure distribution inside tissue, which mirrors absorbing structures and can be measured outside the tissue. Using a temporal back-projection method, the pressure distribution measured on the tissue surface allows us to gain a tomography picture of the absorbing structures inside tissue. This study presents a novel computational algorithm, which, at least in principle, yields an exact reconstruction of the absorbing structures in three-dimensional space inside the tissue. The reconstruction is based on 2D pressure distributions captured outside at different delay times. The algorithm is tested in a simulation and back-projection of pressure transients of a small absorber and a single point source.

Laser solder welding of articular cartilage: tensile strength and chondrocyte viability.

BACKGROUND AND OBJECTIVE: The surgical treatment of full-thickness cartilage defects in the knee joint remains a therapeutic challenge. Recently, new techniques for articular cartilage transplantation, such as mosaicplasty, have become available for cartilage repair. The long-term success of these techniques, however, depends not only on the chondrocyte viability but also on a lateral integration of the implant. The goal of this study was to evaluate the feasibility of cartilage welding by using albumin solder that was dye-enhanced to allow coagulation with 808-nm laser diode irradiation. STUDY DESIGN/MATERIALS AND METHODS: Conventional histology of light microscopy was compared with a viability staining to precisely determine the extent of thermal damage after laser welding. Indocyanine green (ICG) enhanced albumin solder (25% albumin, 0.5% HA, 0.1% ICG) was used for articular cartilage welding. For coagulation, the solder was irradiated through the cartilage implant by 808-nm laser light and the tensile strength of the weld was measured. RESULTS: Viability staining revealed a thermal damage of typically 500 m in depth at an irradiance of approximately 10 W/cm(2) for 8 seconds, whereas conventional histologies showed only half of the extent found by the viability test. Heat-bath investigations revealed a threshold temperature of minimum 54 degrees C for thermal damage of chondrocytes. Efficient cartilage bonding was obtained by using bovine albumin solder as adhesive. Maximum tensile strength of more than 10 N/cm(2) was achieved. CONCLUSIONS: Viability tests revealed that the thermal damage is much greater (up to twice) than expected after light microscopic characterization. This study shows the feasibility to strongly laser weld cartilage on cartilage by use of a dye-enhanced albumin solder. Possibilities to reduce the range of damage are suggested.

Scattering and thermal lensing of 2.12- mum laser radiation in biological tissue.

We studied light propagation of holmium:YAG laser radiation (lambda = 2.12 mum) by measuring the two-dimensional laser beam profile before and after propagation through a tissue sample with a modified fast-temperature-measurement technique. The comparison between water and cartilage tissue allowed us to differentiate between beam broadening caused by formation of a thermal lens and broadening due to light scattering. In water, beam propagation is influenced by formation of thermal lensing, whereas in cartilage the broadening was caused by a combination of light scattering and thermal lensing. Additionally, we discovered that the observed effects are subject to dynamic changes during the laser-tissue interaction.

Optoacoustic tomography: time-gated measurement of pressure distributions and image reconstruction.

Optoacoustic imaging is a potential novel medical imaging technology to image structures in turbid media to depths of several millimeters with a resolution of some tens of micrometers. Thereby short laser pulses generate thermoelastic pressure waves inside a tissue, which are detected on the surface with a wideband ultrasonic transducer. Image reconstruction has the goal of calculating the distribution of the absorbing structures in the tissue. We present a method in which the acoustic field distribution is captured as a two-dimensional snapshot at the sample surface, using an optical-reflectance-based detection principle with a detection resolution of 20 mum. A new image reconstruction is accomplished by backprojection of the detected two-dimensional pressure distributions into the sample volume by use of the delay between the laser pulse and the time the snapshot was taken. Two-dimensional pressure-wave distribution and image reconstruction are demonstrated by simulations and experiments, in which small objects are irradiated with laser pulses of 6-ns duration. The method opens the possibility to irradiate the sample hidden in a light-scattering medium directly through the detector plane, thus enabling front-surface detection of the optoacoustic signals, which is especially important if structures close to the tissue surface have to be imaged. Reconstructed tomography images with a depth resolution of 20 mum and a lateral resolution of 200 mum are presented.

Experimental and theoretical identification of a new high-pressure TiO2 polymorph.

Our combined theoretical and experimental investigations have led to the discovery of a new polymorph of titanium dioxide, where titanium is seven-coordinated to oxygen in the orthorhombic OI ( Pbca) structure. The zero-pressure bulk modulus of the new phase measured in the pressure range 19 to 36 GPa is 318(3) GPa. We demonstrate that the group IVa dioxides (TiO2, ZrO2, HfO2) on compression at ambient temperature all follow the common path: rutile -->alpha-PbO2-type --> baddeleyite-type (MI) --> orthorhombic OI (Pbca) structure --> cotunnite-type (OII).

Effect of osseointegrated implants on the coordination of masticatory muscles: a pilot study.

STATEMENT OF PROBLEM: The neuromuscular network of masticatory function is, in part, coordinated with afferent information provided by the periodontal ligament (PDL). Osseointegrated implant-supported prostheses lack this PDL-derived proprioceptive feedback mechanism. PURPOSE: This pilot study was designed to address the hypothesis that implant patients acquire different patterns of functional coordination. Patients with implant-supported prostheses were characterized in regard to masticatory muscle tenderness and fatigue as well as changes in the coordinated activities of masticatory muscles during chewing and maximal occluding force. Results were compared with those of patients with natural teeth and interpreted to assess the functional outcome of implant therapy. MATERIAL AND METHODS: Fifty-seven volunteers (25 partially edentulous patients restored with implantsupported fixed prostheses; 32 control patients) were evaluated. A comprehensive set of clinical examinations was performed, including occlusal analysis and examination of masticatory muscle and TMJ. EMG recordings of 5 volunteers from each group were further evaluated. EMG activities of the masseter and anterior temporalis were recorded during habitual chewing and voluntary maximal occluding force. RESULTS: There were essentially no differences in the clinical evaluations between volunteers in the implant and control groups and no significant alterations in the masticatory muscle coordination for habitual chewing. During the maximal occluding force measurement, EMG recordings revealed a unique masticatory muscle coordination pattern in the implant group with a tendency to activate the working and nonworking side muscles simultaneously. CONCLUSION: Patients with implant-supported prostheses appeared to be well adapted to perform habitual masticatory functions. However, during a nonhabitual function such as maximal occluding force, our pilot data revealed a less coordinated masticatory muscle activity in the implant patients.

Benchmarking the dental implant evidence on MEDLINE.

The purpose of this study was to estimate the quantity of dental implant literature available on MEDLINE for evidence-based clinical decision-making and to identify its location. A search strategy based on Medical Subject Headings for dental implants was developed to examine MEDLINE using the Ovid Web Gateway search engine. Sensitive and specific methodologic search filters identified 4 categories of information: etiology, diagnosis, therapy, and prognosis. The results were then subdivided by year to identify trends and sorted to identify the sources of publications. The searches identified 4,655 articles published in English between 1989 and 1999 on human dental implants on MEDLINE. The mean number of articles (+/- SD) per year ranged from 15 +/- 11 for specific searches to 107 +/- 50 for sensitive searches. The number of articles increased by 14% to 43% each year for the sensitive search. When subdivided by clinical category, the mean numbers of articles per year for sensitive and specific searches were, respectively: diagnosis 12 +/- 7.5 and 1.5 +/- 1.6, etiology 58 +/- 33 and 1.9 +/- 2.5, therapy 23 +/- 15 and 0.3 +/- 0.5, and prognosis 67 +/- 33 and 12 +/- 8.3. Four dental journals account for approximately half of these publications. These results provide 6 key central findings: (1) there appears to be a substantial literature of clinically relevant information on implants upon which to base clinical decisions; (2) the implant literature is significantly biased toward articles addressing prognosis; (3) to stay current, one would need to read between 1 and 2 articles per week 52 weeks per year, and this number increases significantly each year; (4) approximately 50% of the articles were published in 4 journals, whereas the remainder reside in approximately 97 other journals, making it difficult to stay current; (5) these trends reaffirm the need for lifelong learning; (6) these trends also suggest the need for computer-based clinical knowledge systems.

A 5-year prospective clinical and radiographic study of non-submerged dental implants.

Osseointegrated implants as anchors for various prosthetic reconstructions have become a predictable treatment alternative. It was expected that implants required submucosal placement during the healing period for successful tissue integration. However, it has been demonstrated that healing and long-term health of implants could be achieved with equal predictability in a 1-stage, non-submerged approach. This prospective 5-year study not only calculates implant success by life table analysis, but also evaluates the correlation between observed bone level changes with clinical parameters as measured by suppuration, plaque indices, bleeding indices, probing depth, attachment level and mobility. A total of 112 ITI dental implants were inserted in different areas of the jaws. Clinical and radiographic parameters were evaluated annually for 5 years, whereas a portion of the study group for which 6-year evaluations were available were included in the life-table analysis. The overall success rate after 5 years in service was 99.1%, while after 6 years it was reduced to 95.5% due to the fracture of 3 implants in 1 patient. The mean crestal bone loss experienced during the first year was 0.6 mm followed by an annual yearly loss of approximately 0.05 mm. No significant differences could be found between the amount of bone loss measured at each of the yearly follow-up visits. This suggests that statistically the followed implants did not show any radiographically measurable bone loss following the initial period of bone loss associated with implant placement and osseointegration. Low levels of correlation between the individual and cumulative clinical parameters with radiographically measured bone loss suggests that these parameters are of limited clinical value in assessing and predicting future peri-implant bone loss.

Clinical outcomes of three Parkinson's disease patients treated with mandibular implant overdentures.

Parkinson's disease (PD) often affects the oro-pharyngeal musculature, leading to problems with speaking, chewing and swallowing. The inevitable reduction in food and fluid intake contributes to the further deterioration of neurological symptoms. Parkinson's disease patients have great difficulties in adjusting to the use of complete dentures. It is the purpose of this report to evaluate the benefit of using dental implants combined with overdentures to improve chewing and predigestion capacity in severely handicapped PD patients. Three edentulous PD patients (2 male, 1 female; mean age 75.7 years; mean PD duration 4.3 years; PD severity grade III according to Hoehn and Yahr; mean edentulousness 19.3 years) complaining of poor chewing ability were included in this evaluation. One-stage dental implants were placed in the interforaminal region of the mandible. After completion of healing, new overdentures were fabricated. Custom-made non-rigid (resilient) telescopic attachments were used for retention of the overdentures on the implants. Follow-up examinations of the 3 patients were made between 28 and 42 months after the completion of treatment, and peri-implant tissue conditions as well as the patients' self-assessed satisfaction level were recorded. A modified gastrointestinal symptoms questionnaire, Hoehn and Yahr Scale and body weight measurements were used to monitor gastrointestinal impairment and PD severity. The peri-implant parameters indicated healthy soft tissue conditions and all Periotest values were in the negative range. The patients judged their chewing abilities to be greatly improved. Since placing the implants, PD severity had deteriorated to grade IV (Hoehn and Yahr scale) in 2 patients and was stable in 1 patient. The body weight had improved slightly in all patients (mean 2.2 kg). On the gastrointestinal scale, all patients had improved from a mean score of 8.7 to 5.7. Non-rigid telescopic attachments for overdenture stabilization are particularly suitable for PD patients as they are easy to handle and to clean. The patients reported remarkable improvement in their chewing ability, an assessment which would seem to be supported by the improved gastro-intestinal index. The regimen described appears to be a useful adjunctive treatment in edentulous Parkinson's disease patients and may be considered for patients with diseases similarly affecting motor skills.