Use test with l-carvone in toothpaste on sensitized individuals.

BACKGROUND: The mint flavour carvone (l-carvone) is considered a weak contact allergen. However, contact allergy to carvone is more prevalent in patients with oral lichen planus or oral lichenoid lesions (OLP/OLL). OBJECTIVE: Our aim was to investigate how carvone affects sensitized individuals through a use test with toothpaste containing carvone. Non-flavoured toothpaste served as control. METHODS: Subjects were patch tested prior to the use test-14 subjects allergic to carvone (11 with OLP/OLL), 20 subjects with OLP/OLL and 3 healthy controls. The month-long use test comprised of using toothpaste twice daily. Subjects were examined fortnightly. Clinical signs were assessed with a mucosal scoring system. The subjects' oral health-related quality of life was measured with the oral health impact profile (OHIP-49). RESULTS: Local reactions to the carvone toothpaste presented as aggravated OLL (7/10) and peri-oral eczema (2/10) in allergic subjects. They also had significantly higher mucosal and OHIP scores compared with those receiving non-flavoured toothpaste. CONCLUSION: In sensitized individuals, oral exposure to carvone gives aggravated oral lesions and/or peri-oral eczema. The lesions mimic OLP and allergic individuals are therefore at risk of not being assessed with regard to flavour contact allergy.

Implant and prosthesis failure rates with implant-supported maxillary overdentures: a systematic review.

PURPOSE: To assess the clinical outcomes of maxillary overdentures supported by dental implants by conducting a literature review. MATERIALS AND METHODS: An electronic search was undertaken in March 2019. Eligibility criteria included publications reporting cases of implant-supported maxillary overdentures with follow-up information. RESULTS: A total of 131 publications were included (1,478 overdentures supported by 6,681 implants). The mean number of attachments per overdenture was 3.8 ± 1.2 (range: 1 to 9), and a bar-clip system was used in about half of the cases. The prostheses were followed up for a mean of 47.9 ± 32.8 (range 1: to 240) months. A total of 401 implants (6.0%) failed in 219 patients (14.8%), and 55 prostheses (3.7%) failed at a mean of 40.2 ± 53.2 (6 to 240) months after placement. Most of the failures happened within the first year after placement for both implants (52.1%) and prostheses (41.8%). Patients with fewer implants per prosthesis presented higher prosthesis failure rates than patients with more implants per prosthesis. The cumulative survival rate for dental implants after 19 years was 70.4%, and for implant-supported maxillary overdentures was 79.8%. Presence of palatal coverage and/or metallic structure/reinforcement does not seem to have an influence on failure rate. Of the most commonly used attachment systems, the ball/O-ring and the Ceka were the ones with the highest rates of patients having at least one implant failure. CONCLUSION: Most of the prosthesis failures were due to loss of implants, and the first year was the most critical period for failures. The number of dental implants placed per patient seemed to have an impact on the occurrence of overdenture failure.

A Validation Study of the Impression Replica Technique.

PURPOSE: To validate the well-known and often-used impression replica technique for measuring fit between a preparation and a crown in vitro. MATERIALS AND METHODS: The validation consisted of three steps. First, a measuring instrument was validated to elucidate its accuracy. Second, a specimen consisting of male and female counterparts was created and validated by the measuring instrument. Calculations were made for the exact values of three gaps between the male and female. Finally, impression replicas were produced of the specimen gaps and sectioned into four pieces. The replicas were then measured with the use of a light microscope. The values received from measuring the specimen were then compared with the values received from the impression replicas, and the technique was thereby validated. RESULTS: The impression replica technique overvalued all measured gaps. Depending on location of the three measuring sites, the difference between the specimen and the impression replicas varied from 47 to 130 µm. CONCLUSION: The impression replica technique overestimates gaps within the range of 2% to 11%. The validation of the replica technique enables the method to be used as a reference when testing other methods for evaluating fit in dentistry.

Carvone Contact Allergy in Southern Sweden: A 21-year Retrospective Study.

Carvone (l-carvone), a mint flavour in spearmint oil, is considered a mild skin sensitizer. Carvone-sensitization may be linked to oral/perioral signs and oral lichen planus, but studies are sparse. The prevalence of patch test reactions to carvone and relevant findings from the positive group were investigated. Records for patch-tested patients at the Malmö clinic, for the period 1996 to 2016, were studied. Carvone-positive and carvone-negative patients were compared regarding patch test data from baseline series and dental series. Dental series-tested carvone-positive patients were also compared with a matched group. A total of 147 out of 4,221 referred patients had a positive patch test to carvone. Sensitized patients had higher mean age and were primarily women; 73% had oral signs and 57% had oral lichen. Concomitant patch test reactions to gold, nickel and mercury were common. In the matched group-comparison carvone-positive patients had a higher frequency of oral lichen, but no difference was found in sensitization to gold and mercury.

Quantification of l-carvone in toothpastes available on the Swedish market.

BACKGROUND: Toothpastes have widespread use in the population, and contain flavours to give a pleasant and often minty aroma. Flavours are prevalent allergens in toothpastes, and adverse reactions often present as perioral dermatitis or stomatitis. l-Carvone, a mint flavour found in spearmint oil, is one of these allergens. There are few studies on contact allergy to l-carvone, and some of them have indicated a positive relationship with oral lichenoid lesions. OBJECTIVES: To qualitatively and quantitatively investigate the presence of l-carvone in commercially available toothpastes on the Swedish market. METHODS: l-Carvone in 66 toothpastes was analysed with straight-phase high-performance liquid chromatography. The product labels were studied with regard to limonene. RESULTS: l-Carvone was found in 64 of 66 toothpastes (concentration: 0.00005-0.35%). In 10 of these, the concentration exceeded 0.1%. Higher concentrations of l-carvone were found if limonene was listed on the label. CONCLUSION: The majority of toothpastes on the Swedish market contain l-carvone, but the concentration hardly relates to the advertised flavour or labelled ingredients. It is hitherto unknown whether the found concentrations are sufficient for induction of contact allergy in individuals with healthy oral mucosa or in those with oral lichenoid lesions or other mucosal disease.

The necessity of a test reading after 1 week to detect late positive patch test reactions in patients with oral lichen lesions.

OBJECTIVES: Establishing the clinical relevance of contact allergy to dental materials in patients with oral lichen lesions (OLL) may be difficult, and tests are often read only on day 3 or day 4; also, concentration of the tested allergens may vary. Several studies on dermatitis patients have shown that additional positive patch test reactions can be found after day 4. Therefore, the aim of the present study was to analyse the frequency of late positive reactions to potential allergens in patients with OLL. MATERIAL AND METHODS: Eighty-three of 96 consecutive patients with biopsy-verified OLL were patch-tested with a recently developed lichen series. The patches were removed after 48 h and reactions read 3 and 7 days after application. RESULTS: A total of 129 contact allergies were found, and 26 (20.2 %) of the allergic reactions in 23 patients were seen on day 7 only. The 25.2 % increase in positive test reactions with an additional reading on day 7 in addition to day 3 was statistically significant. Metals were the substances with the highest frequency of late positive reactions. CONCLUSIONS: Patients with OLL cannot be considered properly investigated with regard to contact allergy, unless the testing has been performed with mandatory readings on day 3 (or day 4) and day 7. CLINICAL RELEVANCE: Late patch test readings are crucial in order to elucidate the role of contact allergy to dental materials in the aetiology of OLL.

Contact allergies to potential allergens in patients with oral lichen lesions.

OBJECTIVE: The aim of the present controlled study was to investigate a possible relationship between contact allergies to potential allergens and oral lichen lesions. METHODS: Eighty-three patients with oral lichen lesions (OLL) and control groups of age- and gender-matched dermatitis patients (DP, n = 83) and patch-tested dermatitis patients randomly selected from files (PSFF, n = 319) were included in the study. OLL and DP groups were patch-tested epicutaneously and examined intraorally. RESULTS: The frequencies of contact allergy to mercury and carvone were statistically higher in the OLL group than in the DP group. Surfaces of amalgam and composite restorations were statistically more frequent in the OLL group compared to the DP group. Contact allergy to nickel and colophony, the latter with a statistically significant difference, was more common in the DP group. The numerical difference found for nickel allergy was, however, not significant comparing the OLL and PSFF groups. CONCLUSION: Contact allergy to mercury was overrepresented in patients with OLL and has been reported in previous studies, but the present finding of an overrepresentation of contact allergy to carvone in patients with oral lichen lesions has not been reported previously. CLINICAL RELEVANCE: Carvone, in addition to mercury and gold, as previously suggested, can be one of the causative or maintenant factors for oral lichen lesions. Carvone-hypersensitive patients with oral lichen lesions should therefore avoid carvone-containing products for oral use.

Contact allergy to gold in patients with oral lichen lesions.

The aetiology of oral lichen lesions is obscure. In this study the frequency of contact allergy to gold in 83 patients with oral lichen lesions was compared with that in two control groups, comprising 319 age- and gender-matched patients with dermatitis selected from files and 83 clinically examined dermatitis patients. All patients were tested epicutaneously with gold sodium thiosulphate. The two control groups tested were under examination for a tentative diagnosis of allergic dermatitis not related to oral problems. The frequency of contact allergy to gold was 28.9% in the patients with oral lichen lesions, 18.2% in patients selected from files, and 22.9% in the clinically examined control patients. The difference in frequency between patients with oral lichen lesions and those taken from files was statistically significant.

Levels of gold in plasma after dental gold inlay insertion.

OBJECTIVE: Several studies have reported increased levels of gold (Au) in the blood of patients with dental gold restorations. This study analyzed gold levels in blood plasma before dental gold inlay insertion, 0-12 months after, and 15 years after. MATERIAL AND METHODS: Plasma samples from 9 patients were taken before and 0-10 months after gold inlay insertion. Fifteen years after gold inlay insertion, further blood samples taken from 8 of these patients were analyzed for gold using inductively coupled plasma mass spectrometry. An oral examination was also carried out before and 15 years after gold inlay insertion. RESULTS: Gold levels in plasma were significantly higher 0-12 months after gold inlay insertion than before treatment (p=0.008). No significant difference in gold plasma levels was found between 0-12 months after and 15 years after insertion (p=0.109), although there was a significant correlation between the number of gold alloy surfaces and the amount of gold in plasma 15 years after insertion (p=0.028). CONCLUSIONS: This study supports a dose-related release of gold into plasma from dental gold restorations, a release that appears to be stable over time.

Gold concentration in blood in relation to the number of gold restorations and contact allergy to gold.

Previous studies have demonstrated an association between gold allergy and the presence of dental gold restorations. The aim of the present study was to investigate the relationship between the concentration of gold in blood (B-Au) and the number of tooth surfaces with gold alloys in subjects with and without contact allergy to gold. In 80 patients referred for patch testing because of eczematous disease, blood samples were taken and analyzed for B-Au using inductively coupled plasma mass spectrometry. The detection limit for the Au determination was 0.04 microg/L. In addition, a dentist made a clinical and radiological examination of the patients and registered the number of dental gold surfaces. Patients with dental gold restorations had a statistically significantly higher B-Au in Mann-Whitney U test (P = 0.025), (range < 0.04-1.07 microg/L) than patients without (range < 0.04-0.15 microg/L). Furthermore, a positive correlation was found between B-Au and the number of dental gold surfaces (P < 0.01). There was no statistically significant difference in B-Au between persons with and without contact allergy to gold. The study thus indicates that gold is released from dental restorations and taken tip into the circulation.

Contact allergy to gold is correlated to dental gold.

Questionnaire studies have indicated that patients with dental gold will more frequently have contact allergy to gold. This study aimed at investigating the relationship between contact allergy to gold and the presence and amount of dental gold alloys. A total of 102 patients were referred for patch testing because of suspicion of contact allergy. Patch tests were performed with gold sodium thiosulphate 2% and 5%. The patients underwent an oral clinical and radiological examination. Contact allergy to gold was recorded in 30.4% of the patients, and of these 74.2% had dental gold (p=0.009). A significant correlation was found between the amount of gold surfaces and contact allergy to gold (p=0.008), but there was no statistical relationship to oral lesions. It is concluded that there is a positive relationship between contact allergy to gold and presence and amount of dental gold alloys.