Infinite getPrev and getNext? I know how to display every next entry, but is it possible when there is no next entry it displays the first one and if there isn’t a previous display the last entry?
You would need query for these entries using the first and the last method.

{% set criteria = craft.entries.section('blog').order('title asc') %}

{% set prevEntry = entry.getPrev(criteria) ?: criteria.last() %}
{% set nextEntry = entry.getNext(criteria) ?: criteria.first() %}

&lt;a href="{{ prevEntry.url }}"&gt;{{ prevEntry.title }}&lt;/a&gt;
&lt;a href="{{ nextEntry.url }}"&gt;{{ nextEntry.title }}&lt;/a&gt;