The Social Democratic Party of Germany (SPD) is generally considered to be a center-left party. While it has historically positioned itself as a party representing the interests of the working class and advocating for social justice and welfare policies, it has also embraced more centrist positions on certain economic and social issues. The SPD has been part of coalition governments with both center-right and center-left parties, demonstrating its willingness to work across the political spectrum. Overall, the SPD's ideology and policy positions place it closer to the center-left than the center of the political spectrum. **

The most centrist party in Germany is the Free Democratic Party (FDP). The FDP advocates for a liberal and market-oriented economic policy, while also supporting individual freedoms and civil rights. It is known for its pro-business stance and its emphasis on personal responsibility. The FDP has often been a coalition partner in German governments, working with both conservative and progressive parties, which reflects its centrist position in the political spectrum. **

Right-wing and centrist parties in Germany have achieved several important accomplishments. For example, they have implemented economic reforms that have helped to strengthen the German economy and maintain its position as a leading global economic power. Additionally, they have worked to improve the country's infrastructure and invest in renewable energy, contributing to Germany's reputation as a leader in sustainability. Furthermore, these parties have also played a key role in maintaining stability and promoting cooperation within the European Union, contributing to the overall peace and prosperity of the region. **

The CSU (Christian Social Union) is generally considered a center-right party in Germany. While it is part of the conservative bloc along with the CDU (Christian Democratic Union), the CSU has a more regional focus on Bavaria and tends to take more conservative stances on certain issues compared to the CDU. Some may view the CSU as a healthy right-wing party due to its emphasis on traditional values and strong stance on law and order, but it is not typically classified as an extreme right-wing party. **

Both "Zähne putzen" and "Zähne bürsten" are commonly used in German to refer to the act of brushing teeth. "Zähne putzen" directly translates to "cleaning teeth," while "Zähne bürsten" translates to "brushing teeth." Both phrases are widely understood and used interchangeably in everyday language. **

Good oral hygiene involves maintaining a routine of daily practices to keep your mouth clean and healthy. This includes brushing your teeth at least twice a day with fluoride toothpaste, flossing daily to remove plaque and food particles between teeth, and using mouthwash to kill bacteria. Regular dental check-ups and cleanings are also important to prevent and detect any oral health issues early on. Additionally, avoiding tobacco products and maintaining a balanced diet can contribute to good oral hygiene. **

Private health insurance typically does not cover teeth whitening procedures, as they are considered to be cosmetic treatments rather than medically necessary. However, some dental insurance plans may offer coverage for teeth whitening as part of a broader dental care package. It's important to check with your insurance provider to understand what specific dental treatments are covered under your plan. **

Based on the information provided, it is not possible to determine if the friend has poor oral hygiene. The fact that the friend has not visited a dentist in several years could indicate poor oral hygiene, but it could also be due to other reasons such as fear of the dentist, financial constraints, or simply not feeling the need to go. Without more information, it would be unfair to make assumptions about the friend's oral hygiene. **