Biomedical subjects

R D Hilgers

Publications and source records attributed to R D Hilgers.

At least 19 recordsLinked to original sources

PubMed1999

Long-term fluctuations of the normalised rim/disc area ratio quotient in normal eyes.

BACKGROUND: The assessment of the cup of the optic disc in follow-up of glaucomatous optic nerve heads depends on the variability of the cup area over time. We examined the variability of topographic measurements depending on scan focus settings and evaluated the long-term fluctuations of the normalised rim/disc area ratio quotient of normal subjects for 1 year. METHODS: Part 1. Evaluation of the influence of scan focus and corneal curvature on the number of pixels per millimetre in one emmetropic volunteer. The scan focus was varied using contact lenses of different refraction. Part 2. HRT examinations of the optic nerve head of five eyes of five volunteers were repeatedly recorded during a 12-month period. The contour line from the first mean topographic image was transferred into the following seven mean topographic images of each subject. RESULTS: Part 1. The size of pixels depends on the adjusted scan focus for mean corneal curvature radius between 6 and 9 mm. However, after image to image scaling the size of pixels is nearly independent to the scan focus. Part 2. We found the highest variation of normalised rim/disc area ratio for the location of the temporal horizontal sectors, followed by the temporal inferior and the temporal superior sectors. Variation was smallest in the nasal sectors. Mean fluctuation of the normalised rim/disc area ratio quotient of the 95th percentile was 0.09 following image to image scaling compared to 0.16 when using individual image scaling. CONCLUSION: Scan focus variation during HRT follow-up examinations can influence optic disc parameters, especially when image to image scaling has not been performed. A confidence area of an individual optic disc could now be calculated. These confidence bands could help to distinguish more easily between progress of glaucomatous optic nerve head damage and physiological intertopographic variation of optic cup measurements. A decrease of more than 43% in the fluctuations of the normalised rim/disc area ratio could be achieved using image to image scaling techniques. For that reason follow-up of glaucomatous optic nerve heads should only be performed using this software application.

Adult↗

PubMed1998

Adjunctive daunorubicin in the treatment of proliferative vitreoretinopathy: results of a multicenter clinical trial. Daunomycin Study Group.

PURPOSE: To assess the efficacy and safety of adjunctive daunorubicin during vitrectomy surgery in eyes with idiopathic proliferative vitreoretinopathy (PVR). METHODS: Two hundred eighty-six eyes (286 patients) with stage C2 (Retina Society Classification, 1983) or more advanced preoperative PVR in which surgery with silicone oil was planned were enrolled in a multicenter, prospective, randomized, controlled clinical trial. Standardized surgery plus adjunctive daunorubicin perfusion was compared with surgery alone. Outcomes assessed were retinal attachment without additional vitreoretinal surgery 6 months after standardized surgery, number of and time until vitreoretinal reoperations within 1 year of standardized surgery, and change in visual acuity 1 year after standardized surgery, evaluated by photodocumentation, number of reoperations, and measurement of best-corrected visual function. Outcomes were determined 6 months after operation and reevaluated after 1 year of follow-up. RESULTS: Six months after standardized surgery, complete retinal reattachment without additional vitreoretinal surgery was achieved in 62.7% (89/142) of eyes in the daunorubicin group vs 54.1% (73/135) in the control group (P = .07, one-sided). However, in the daunorubicin group, significantly fewer vitreoretinal reoperations were performed within 1 year postoperatively (P = .005, one-sided) to achieve the same overall 1-year retinal reattachment rate (80.2% [105/131] vs 81.8% [103/126]). The rate of patients with no vitreoretinal reoperations was 65.5% (95/145) in the daunorubicin group vs 53.9% (76/141) in the control group. There was no difference in the best-corrected visual acuity. No severe adverse effect related to daunorubicin was identified. CONCLUSIONS: Although the rate of anatomic success after 6 months failed to show significance, some benefit of the adjunctive treatment exists, especially a tendency toward increased rate of reattachment and a significant reduction in the number of reoperations. This shows that human PVR is amenable to pharmacologic treatment.

Adult↗

PubMed1998

Significance of trigeminal sensory input on regrowth of hypoglossal and facial motoneurons after hypoglossal facial anastomosis in rats.

Hypoglossal facial anastomosis (HFA) is a standard surgical technique for restoration of facial movements in cases of intratemporal lesions of the facial nerve. Case reports provide evidence that an affected trigeminal system reduces functional outcome. In order to detect morphological changes in the hypoglossal nucleus responsible for this phenomenon, we used 18 Wistar rats and performed three different surgical combinations. In group 1, six animals received HFA only. In group 2, HFA was combined with resection of the contralateral infraorbital nerve. In group 3, HFA was combined with resection of the ipsilateral infraorbital nerve. Fifty-six days after the operation, horseradish peroxidase (HRP) was injected into the whisker pad. As shown in previous studies using HRP, retrograde-labelled motoneurons occurred in the hypoglossal and facial nuclei. Counts of the labelled motoneurons showed no change in the number of projecting hypoglossal motoneurons in group 2 when compared to HFA only, but a significantly smaller number in group 3 (-35%). Furthermore, the number of projecting facial motoneurons was significantly reduced in group 2 (-85%) and group 3 (-45%). These morphological findings indicate an absent or insufficient functional connection between the contralateral infraorbital nerve and the hypoglossal nucleus, and a strong influence of the infraorbital nerve to the ipsi- and contralateral facial nuclei. Additionally, our study provides morphological evidence that the integrity of the sensory trigeminal system is very important in reconstructive facial nerve surgery.

Analysis of Variance↗

PubMed1998

Slime production of Staphylococcus epidermidis: increased bacterial adherence and accumulation onto pure titanium.

In an in vitro study using Staphylococcus epidermidis RP 62 A, a slime-producing strain and its isogenic slime-negative mutant M7, we demonstrated that both strains adhere to pure titanium discs with significantly higher colony counts for the slime-producing strain. The colony count was dependent on temperature, time and strain. Prolonged incubation time (24 h) under growth conditions leads to higher colony counts for the slime-producing strain RP 62 A. As the slime-negative mutant M7 can adhere to, but not form multiple layers on metallic surfaces, increase of incubation time does not produce higher colony counts on the metallic surface. We conclude that slime production is important for adherence and subsequent accumulation of S. epidermidis onto pure titanium discs in vitro.

Analysis of Variance↗

PubMed1997

Effect of tooth preparation design on bond strengths of resin-bonded prostheses: a pilot study.

STATEMENT OF PROBLEM: The success rate of resin-bonded fixed partial dentures is directly related to the adhesive system and the tooth preparation design for good retention. PURPOSE OF STUDY: This in vitro study evaluated the effect of various tooth preparation designs on the bond strength of retainers for adhesive fixed partial dentures. MATERIAL AND METHODS: Molar teeth were prepared in the conventional form or with occlusal coverage and opposing grooves and retainers were silicoated and bonded to etched enamel by a bis-glycerol methacrylate adhesive. Bond strengths were determined after water storage and thermocycling. RESULTS: The least mean bond strength was recorded for the conventional form of tooth preparation (p < 0.05). CONCLUSION: A combination of 180-degree opposing groove placement at line angles "wraparound" and occlusal coverage resulted in the greatest bonding values.

Analysis of Variance↗

PubMed1997

Spontaneous intracerebral hemorrhage. Prognostic factors in 896 cases.

To determine the prognostic value of etiology and localization in spontaneous intracerebral hemorrhage, 896 patients with spontaneous intracerebral hemorrhage, as proven by CT, operation or autopsy, were retrospectively studied using univariate data analysis. Etiologies were hypertension in 63.5%, cerebrovascular malformations in 8.5% and abnormal hemostasis in 15% of the patients. In 23% no etiology was determined. Main localizations were cerebral lobes in 49.2%, basal ganglia in 34.4%, brain stem in 6.9%, cerebellum in 6.7% and primary intraventricular in 2.3% of the patients. Ventricular extension was present in 47.0%. A higher case fatality correlated with: 1) ventricular extension (P < 0.00001), 2) increasing age (P = 0.00005), 3) surgical treatment (P = 0.00010), 4) localization in basal ganglia (P = 0.0108) and 5) hypertension as only etiology (P = 0.01471). A lower case fatality was found in patients with cerebrovascular malformations (P = 0.00006) and when the hemorrhage was localized to the cerebral lobes (P = 0.0050). We conclude that etiology and localization are of prognostic value in spontaneous intracerebral hemorrhage.

Adolescent↗

PubMed1996

Sequential granulocyte colony-stimulating factor increases cisplatin cytotoxicity in human epithelial ovarian cancer cell lines.

BACKGROUND: To determine the effect of granulocyte colony-stimulating factor (G-CSF) on tumor growth and cisplatin cytotoxicity in human epithelial ovarian cancer. METHODS: Six human epithelial ovarian cancer cell lines were treated with media (control) for 24 hr, G-CSF for 24 hr, cisplatin for 24 hr, simultaneous cisplatin and G-CSF for 24 hr, media (control) for 48 hr, cisplatin for 24 hr and sequential media for 24 hr, cisplatin for 24 hr, and sequential G-CSF for 24 hr. Following incubation, the percentage cell lysis was determined by particle concentration fluorescein immunoassay chemosensitivity assay. RESULTS: G-CSF resulted in tumor cell growth (7-19%) in three cell lines. Simultaneous G-CSF decreased cisplatin cytotoxicity in five cell lines (7-45%). Sequential G-CSF increased cisplatin cytotoxicity in all six cell lines (5-108%). CONCLUSIONS: G-CSF may result in ovarian cancer proliferation. Simultaneous G-CSF may decrease cisplatin cytotoxicity, while sequential G-CSF appears to increase cisplatin cytotoxicity.

Cell Division↗

PubMed1996

Prophylactic granulocyte colony-stimulating factor allows escalation of chemotherapeutic dose intensity in advanced epithelial ovarian cancer.

BACKGROUND: In an effort to discover an effective regimen for use in Phase III evaluation of the efficacy of dose intensification in advanced ovarian cancer, we performed a Phase II trial of dose intensified cisplatin, etoposide, and ifosfamide with granulocyte colony-stimulating factor (G-CSF). METHODS: Thirty patients with primary, FiGO Stage 3 or 4, epithelial ovarian cancer underwent intensified cytoreduction followed by cisplatin 105 mg/m2, etoposide 300 mg/m2 and ifosfamide/mesna 3 g/m2, q 28 days x 6 cycles with G-CSF 5 microg/kg q day for 7 days. The dose of etoposide and ifosfamide was escalated 20% in cohorts of three patients. RESULTS: Intensified cytoreductive surgery was successful in resecting all gross tumor in 24 patients (80%). At the original dose of cisplatin, etoposide, and ifosfamide without G-CSF, 55% of cycles resulted in neutropenia and 38% in thrombocytopenia (dose intensity = 0.8). With the addition of G-CSF, neutropenia developed in 5% of cycles and thrombocytopenia in 38%. At a 20% escalation of etoposide and ifosfamide, neutropenia developed in 17% of cycles and thrombocytopenia in 50% (dose intensity = 1.2). At a 40% escalation of etoposide and ifosfamide, neutropenia developed in 33% of cycles and thrombocytopenia in 83%, which was dose limiting. The remaining 18 patients were treated at a 20% escalation and neutropenia developed in 14% of cycles and thrombocytopenia in 36%. CA125 response was 73%. At a 4.1-year median follow-up, median progression-free survival was 2.6 years and median survival was 3.0 years. CONCLUSION: In 30 women with primary advanced ovarian cancer, G-CSF allowed a 50% dose escalation of etoposide and ifosfamide from 0.8 to 1.2 dose intensity. The maximum tolerated dose of this regimen is cisplatin 105 mg/m2, etoposide 360 mg/m2, and ifosfamide 3.6 g/m2 with G-CSF.

Adult↗

PubMed1996

The cumulative normalised rim/disc area ratio curve.

BACKGROUND: The assessment of the cup of the optic disc depends, among other criteria, on the disc area. A small cup in a small optic disc can indicate an advanced glaucomatous lesion, while on the other hand a large cup in a large optic disc can be normal. Therefore, a cumulative normalised rim/disc area ratio curve could help to distinguish between glaucomatous and normal optic cups. The aim of our study was to calculate normalised rim/disc area ratio curve. METHODS: Heidelberg Retina Tomograph examinations of the optic nerve head of 100 randomly selected eyes of 100 normal subjects were evaluated. We calculated the disc area-adjusted normalised rim/disc area ratio in sectors of 10 degrees. The 95th, 90th and 50th percentiles of each of the 36 sectors were displayed in descending order. RESULTS: In relation to the normal percentile curves, it is possible to display an individual normalised rim/disc area ratio curve. We obtained such curves for a normal optic disc, optic nerve heads with moderate and advanced lesions and a small optic disc with glaucomatous damage. CONCLUSION: We present a new display mode for the results of Heidelberg Retina Tomograph optic nerve head examination, which may be helpful for easy and reliable assessment of the local, diffuse and combined components of glaucomatous optic nerve head damage depending on optic disc size.

Adult↗

PubMed1996

Surgical staging and high dose rate brachytherapy for endometrial cancer: limiting external radiotherapy to node-positive tumors.

OBJECTIVE: To evaluate the efficacy and morbidity of surgical staging and high dose rate brachytherapy for women with stage I-IIIA endometrial cancer. METHODS: Sixty consecutive patients underwent surgical staging consisting of total abdominal hysterectomy, bilateral salpingo-oophorectomy, peritoneal cytology, bilateral pelvic lymphadenectomy, periaortic lymphadenectomy, and omentectomy. High dose rate brachytherapy was delivered postoperatively in three fractions for a total of 2100 cGy. Only patients with nodal metastasis received external radiotherapy. RESULTS: Twenty-two tumors (37%) were considered high-risk uterine disease because of deep invasion (stage IC), cervical involvement (stage II), positive peritoneal cytology (stage IIIA), or poor differentiation (grade 3). Lymph node metastases were detected in five patients. There was no surgical mortality, and morbidity from surgery and high dose rate brachytherapy was minimal. At a median follow-up of 3 years, there has been one recurrence. The conventional practice of postoperative external radiotherapy was altered in 23 of 60 patients (38%): 22 women with high-risk uterine factors did not receive external radiotherapy, and one patient with low-risk uterine factors (less than 50% myometrial invasion, grade 2) received external radiotherapy because of microscopic pelvic lymph node metastasis. CONCLUSION: Surgical staging and high dose rate brachytherapy without external radiotherapy for stage I-IIIA endometrial cancer were associated with minimal morbidity and produced excellent survival.

Adenocarcinoma↗

PubMed1996

Sleep apnoea in treated acromegaly: relative frequency and predisposing factors.

OBJECTIVES: Sleep apnoea is common in active acromegaly. It is associated with increased morbidity and mortality but can be treated effectively. The objective of this study was to determine the largely unknown relative frequency of, and the predictive factors for, sleep apnoea in treated acromegalic patients. DESIGN: Retrospective cohort study. SETTING: Tertiary referral hospital. PATIENTS: Fifty-four of 100 patients with treated acromegaly. If sleep apnoea had been diagnosed before acromegaly, the patient was excluded. MEASUREMENTS: Sleep studies (using the MESAM-4 device measuring oxyhaemoglobin saturation, heart rate, snoring sounds and body position to determine presence and severity of sleep apnoea); GH and IGF-I levels; body mass index, neck and index-finger circumference; daytime symptoms of sleep apnoea, duration of acromegaly before treatment, shoe and neck-size difference since beginning of acromegaly; age, sex and treatment modes of acromegaly. RESULTS: The relative frequency of sleep apnoea was 39% in the 54 patients with sleep studies and at least 21% in the entire study population of 100 patients. In patients with sleep apnoea, statistically significant higher values were observed for GH (P = 0.002), IGF-I (P = 0.029), age (P = 0.014) and neck circumference (P = 0.016). An index-finger circumference of > or = 8.5 cm was associated with a significantly higher desaturation index (P = 0.012, Mann-Whitney U-test). Adenomectomy had been performed significantly less frequently in patients with sleep apnoea (P < 0.001, X2 test). The body mass index was non-significantly higher in the patients with sleep apnoea. CONCLUSIONS: The relative frequency of sleep apnoea in patients with treated acromegaly is at least 21%. Parameters of predictive value for the presence of sleep apnoea in this population are neck and index-finger circumference as measures of soft tissue hypertrophy, age, GH and IGF-I levels, and whether or not operative therapy was applied.

Acromegaly↗

PubMed1996

Fosinopril improves regulation of vascular tone in mesenteric bed of diabetic rats.

Because diabetes mellitus leads to vascular dysfunction, we examined the microvascular endothelial and smooth muscle function in long-term diabetes and a possible influence of fosinopril treatment (10 mg/kg). We investigated isolated perfused mesenteric beds of diabetic rats (4 groups: control, control + fosinopril, diabetes, diabetes + fosinopril; diabetes of 6-month duration, induced by streptozotocin, STC) were investigated using computer-assisted microvideoangiometry. Vascular diameter of four different vascular regions [classified as conductive (G1, 303 +/- 6.5 mu m and G2, 239 +/- 6.3 mu m) and resistance (G3, 192 +/- 4.5 mu m and G4, 124 +/- 2.6 mu m) vessel generations; resting conditions, control group] were increased in diabetes by approximately 20%. However, the endothelium-dependent relaxation in response to 1 mu M acetylcholine (ACh) was reduced from 38-44% to 20-25% (diabetes mellitus) with maximal impairment in G4 vessels. This could be significantly antagonized by fosinopril treatment. Similarly, vasodilation in response to 1 mu M glyceroltrinitrate (GTN) was reduced from 50-58 to 20-30%, but was partially prevented by fosinopril (32-38%), whereas potassium chloride (KCl)-induced vasoconstriction did not show differences between the groups. Inhibition of nitric oxide (NO) synthesis by 3 mu M L-NG-nitro arginine (L-NNA) resulted in a slight vasoconstriction of all vessels (12-25%), with maximum response in G3/G4. This was not altered by disease or treatment. We conclude that (a) long-term diabetes leads to endothelial and smooth muscle dysfunction with reduced capability of vasodilation and either an impairment of NO release or a reduced smooth muscle responsiveness to and (b) a predominant impairment of NO-dependent regulation in small resistance vessels, and (c) that fosinopril treatment can at least partially prevent this vascular dysfunction.

Angiotensin-Converting Enzyme Inhibitors↗

PubMed1996

False positive malignant peritoneal cytology and psammoma bodies in benign gynecologic disease.

OBJECTIVE: To determine the incidence of false positive malignant peritoneal cytology and psammoma bodies associated with benign gynecologic disorders. STUDY DESIGN: Pelvic peritoneal fluid was prospectively collected for cytologic examination from 119 women undergoing laparoscopy for benign conditions (infertility, 67; pelvic pain, 35; elective sterilization, 17). The median age was 30. No patient had laparoscopic gross cancer or histologic evidence of cancer. RESULTS: The peritoneal cytology of 2 of 119 cases (2%) contained cells with features suggestive of malignancy, and 6 of 119 cases (5%) contained psammoma bodies. Both cases of false positive peritoneal cytology and four of six with psammoma bodies were associated with endometriosis. All cases were followed for a minimum of two years, and no patient had developed cancer. CONCLUSION: Peritoneal fluid from cases of benign gynecologic disorders, especially endometriosis, can contain psammoma bodies and cells suggestive of malignancy.

Adult↗

PubMed1995

Conservative management of chemotherapeutic-induced thrombocytopenia in women with gynecologic cancers.

During the course of four recent dose-intense chemotherapy trials, the routine practice of transfusing patients with platelet counts < 20,000/microliters was changed to a more conservative style of management limiting prophylactic transfusions to patients with platelet counts < 5000/microliters. One hundred seventy-nine episodes of thrombocytopenia in 46 patients enrolled in four dose-intense chemotherapy trials were evaluated. Thirty-two patients had advanced carcinoma of the ovary, 10 had pelvic sarcomas, and 4 had cervical cancer. Of the 179 episodes of thrombocytopenia evaluated, 100 exhibited severe thrombocytopenia (platelet count < 20,000/microliters). Of these 100 episodes, 30 received prophylactic platelet transfusions while 70 did not. Thirty-eight episodes of thrombocytopenia were 5000-10,000/microliters, 24 of which received prophylactic platelet transfusions while 14 did not. Eighteen episodes (10%) of thrombocytopenia resulted in minor bleeding and all occurred during severe thrombocytopenia. Minor bleeding occurred in 27% of episodes of severe thrombocytopenia receiving prophylactic platelet transfusions versus 14% not transfused (P = 0.2). Of the 38 episodes of thrombocytopenia 5000-10,000/microliters, minor bleeding occurred in 17% receiving prophylactic platelet transfusions versus 24% not transfused (P = 0.95). None of the 179 episodes of thrombocytopenia resulted in major bleeding, including 70 episodes of thrombocytopenia < 20,000/microliters not receiving prophylactic platelet transfusions which included 14 episodes of thrombocytopenia between 5000-10,000/microliters. In conclusion, in women with gynecologic cancer and chemotherapy-induced thrombocytopenia, we safely limited prophylactic platelet transfusions for episodes of thrombocytopenia < 5000/microliters. We hope our study will prompt prospective, randomized trials evaluating the need of prophylactic platelet transfusions for chemotherapy-induced thrombocytopenia in patients with solid tumors.

Adult↗

PubMed1995

Cisplatin, 5-fluorouracil, and ifosfamide in the treatment of recurrent or advanced cervical cancer.

We performed a prospective, phase II trial of cisplatin, 5-fluorouracil, and ifosfamide in the treatment of 30 women with recurrent or advanced cervical cancer. Median age was 47 years old. Twenty-one tumors were squamous and 83% of tumors were grade 2 or 3. Twenty-six patients (87%) received prior pelvic radiotherapy, and six patients (20%) received prior radiation sensitizing chemotherapy. Median time to recurrence was 6 months. In 11 patients (37%) tumor recurred in the pelvis. A combination of cisplatin 90 mg/m2, 5-fluorouracil 1500 mg/m2, and ifosfamide 3 g/m2 was administered intravenously in divided doses over 3 consecutive days every 28 days. Sixteen patients (53%) responded to chemotherapy with a complete response occurring in 5 patients (17%) and a partial response in 11 patients (36%). One of 11 patients (7%) with a pelvic recurrence responded compared to 15 of 19 (79%) with extrapelvic recurrence (P = 0.001). Tumors recurring after 6 months had a higher response rate (73%) compared to those recurring before 6 months (33%) (P = 0.05). Three of the six patients (50%) treated with prior radiation sensitizing chemotherapy responded. Seven of nine patients (78%) with adenocarcinoma responded. Median survival is 12 months (3-36 months). In conclusion, cisplatin, 5-fluorouracil, and ifosfamide resulted in a favorable response rate (53%) and a median survival of 12 months. As expected, patients with extrapelvic recurrence and recurrence after 6 months had an improved response rate while, surprisingly, those receiving prior radiation sensitizing chemotherapy and those with adenocarcinoma did not exhibit a less favorable response rate.

Adenocarcinoma↗

PubMed1995

Loop electrosurgical excision procedure for intensified cytoreduction of ovarian cancer.

The objective was to evaluate the loop electrosurgical excision procedure (LEEP) for intensified cytoreduction of ovarian cancer. Twenty consecutive women with residual epithelial ovarian cancer following maximum cytoreduction by standard surgical techniques were treated with LEEP-intensified cytoreduction. LEEP was employed to resect metastases involving intestines (18 patients), diaphragm (3 patients), liver (6 patients), spleen (3 patients), and peritoneal surface (18 patients). Median LEEP time was 9 min (range 3-27 min). Blood loss secondary to LEEP was minimal with no patient experiencing bleeding > 20 ml. Following LEEP-intensified cytoreduction, 17 of 20 patients (85%) had no gross residual disease. Seventeen of 18 patients (94%) had all intestinal metastases resected. All superficial liver (6 patients) and splenic metastases (3 patients) were completely resected. Peritoneal metastases were completely resected in all 18 patients. No patient experienced a complication directly related to LEEP. LEEP can be performed rapidly, with minimum blood loss, and results in intensified cytoreduction with minimal morbidity.

Adult↗

PubMed1995

[The force transmission of positioners in different degrees of incisor protrusion. An in-vitro study].

The purpose of this study was to examine the forces exerted on protruded upper incisors by tooth positioners. Methodologically an in vitro force measurement model was used. The tooth positioners were made of 7 readily available materials commonly used in orthodontics. The study found that the values of the forces, which ranged from 0.4 N to 14.0 N per tooth, are dependent on the material used and the degree of tooth protrusion. In addition, the study analyzed the changes in force over a 3-month period during which time the positioners were stored at 37 degrees +/- 1 degree C in an aqueous environment. This environment corresponds closely to that found in the mouth.

Dental Articulators↗

PubMed1995

Fluoride retention of incipient enamel lesions after treatment with a calcium fluoride varnish in vivo.

The aim was to determine the fluoride retention in plaque-covered and clean incipient enamel lesions after topical application of a CaF2/NaF varnish (Bifluorid 12). In 50 specimens of bovine enamel an incipient lesion was produced with acidic hydroxyethylcellulose (pH 4.8; 72 h). 40 specimens were fluoride varnished; the 10 remaining specimens were used for measuring baseline fluoride content. Each six of the fluoridated specimens were recessed in the buccal aspects of an intraoral appliance worn for 5 days. During the experimental period one side of the appliance was kept clean, and plaque growth was allowed on the other. KOH-soluble and structurally bound fluoride were determined immediately, 1 day, 3 days and 5 days after fluoridation, and compared with the baseline fluoride content of the enamel. Immediately after fluoridation, a considerable amount of KOH-soluble fluoride was bound, but after 5 days 80% had been lost. Simultaneously a significant increase of non-KOH-soluble or structurally bound fluoride was detected in both plaque-covered and clean enamel. It is evident that this CaF2/NaF varnish deposits more KOH-soluble fluoride on the surface of demineralized enamel than other varnishes, but after 5 days fluoride retention is similar to that from other varnishes.

Analysis of Variance↗